978 lines
36 KiB
Python
978 lines
36 KiB
Python
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import gc
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import os
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import numpy as np
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import sys
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import xarray as xr
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import rasterio
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from rasterio.windows import Window
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import spectral
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from brdf_model_M02 import M02
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from brdf_model_M02SeaDAS import M02SeaDAS
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from brdf_model_L11 import L11
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from brdf_model_O25 import O25
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from brdf_utils import ADF_OCP, squeeze_trivial_dims
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# 尝试导入 tqdm 进度条库，如果不可用则设为 None
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try:
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from tqdm import tqdm
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except ImportError:
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tqdm = None
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UNC_LUT_CACHE = {}
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"""
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主 BRDF 校正模块
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输入为 xarray 数据集
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所需的光谱维度为 "bands"，其他维度自由
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输入数据集中必填的字段：
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Rw: 方向性海洋反射率
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sza: 太阳天顶角
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vza: 观测天顶角
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raa: 相对方位角（当太阳和观测在同一侧时，raa=0）
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输入数据集中可选的字段：
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Rw_unc: Rw 的不确定度（若缺失，设为零）
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输出数据集中的字段：
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nrrs: 完全归一化的遥感反射率
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rho_ex_w: nrrs * PI
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omega_b: bb/(a+bb)
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eta_b: bbw/bb
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C_brdf: BRDF 校正因子
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brdf_unc: C_brdf 的不确定度
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nrrs_unc: nrrs 的不确定度
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使用和适配 brdf_hypercp 模块需保留的信息：
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Brdf_hypercp 是 EUMETSAT 研究项目的一部分
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"BRDF correction of S3 OLCI water reflectance products"（S3 OLCI 水体反射率产品的 BRDF 校正），
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合同号：RB_EUM-CO-21-4600002626-JIG。
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研究团队成员：Davide D'Alimonte (davide.dalimonte@aequora.org)，
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Tamito Kajiyama (tamito.kajiyama@aequora.org)，
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Jaime Pitarch (jaime.pitarchportero@artov.ismar.cnr.it)，
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Vittorio Brando (vittorio.brando@cnr.it)，
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Marco Talone (talone@icm.csic.es) 以及
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Constant Mazeran (constant.mazeran@solvo.fr)。
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BRDF 查找表中的相对方位角遵循 OLCI 约定。详见 https://www.eumetsat.int/media/50720，图 6。
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"""
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# ---------------------------------------------------------------------------
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# File I/O helpers
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# ---------------------------------------------------------------------------
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def _resolve_envi_header(filepath):
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"""Return the ENVI header path accepted by spectral."""
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if filepath.lower().endswith(".hdr"):
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return filepath
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hdr_path = filepath + ".hdr"
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if os.path.exists(hdr_path):
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return hdr_path
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base, _ext = os.path.splitext(filepath)
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hdr_path = base + ".hdr"
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if os.path.exists(hdr_path):
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return hdr_path
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return filepath
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def read_bsq(filepath, wavelengths=None, dtype=np.float32):
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"""Read an ENVI BSQ hyperspectral image.
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Parameters
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----------
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filepath : str
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Path to the ENVI header (.hdr) or image file.
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wavelengths : array-like, optional
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Band centre wavelengths in nm. When *None*, wavelengths are read
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from the ENVI header if available.
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Returns
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-------
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data : ndarray, shape (bands, rows, cols), float64
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wavelengths : ndarray, shape (bands,)
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img : spectral image object (metadata / transform access)
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"""
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img = spectral.open_image(_resolve_envi_header(filepath))
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data = np.asarray(img.open_memmap(interleave="source"), dtype=dtype)
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# data = np.transpose(data, (2, 0, 1)) # -> (bands, rows, cols)
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if wavelengths is None:
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if hasattr(img, 'bands') and img.bands.centers is not None:
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wavelengths = np.array(img.bands.centers, dtype=np.float32)
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else:
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n_bands = data.shape[0]
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wavelengths = np.arange(1, n_bands + 1, dtype=np.float32)
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return data, np.asarray(wavelengths, dtype=dtype), img
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def relative_azimuth_olci(saa_deg, vaa_deg):
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"""Relative azimuth (RAA / delta_phi) in [0, 180] deg, OLCI convention.
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Same convention as the module docstring: sun and sensor on the same side -> RAA = 0.
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"""
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saa = np.asarray(saa_deg, dtype=np.float64)
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vaa = np.asarray(vaa_deg, dtype=np.float64)
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d = np.abs(saa - vaa)
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out = np.minimum(d, 360.0 - d)
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return out.astype(np.float32)
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def read_bip_angles(filepath, dtype=np.float32):
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"""Read an ENVI BIP geometry file (10 bands) and build BRDF angles.
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Band layout (1-indexed), last dimension = band (BIP):
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1 path length
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2 to-sensor azimuth (VAA)
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3 to-sensor zenith (VZA)
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4 to-sun azimuth (SAA)
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5 to-sun zenith (SZA)
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6 phase angle
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7 slope
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8 aspect
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9 cosine i
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10 UTC time
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RAA is not stored; it is computed from SAA and VAA via :func:`relative_azimuth_olci`.
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Parameters
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----------
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filepath : str
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Path to the ENVI BIP file (header or image file).
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Returns
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-------
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dict with keys 'sza', 'saa', 'vza', 'vaa', 'raa'.
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Each value is a 2-D ndarray of shape (rows, cols).
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"""
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img = spectral.open_image(_resolve_envi_header(filepath))
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data = np.asarray(img.open_memmap(interleave="source"), dtype=dtype)
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n_bands = data.shape[2]
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if n_bands != 10:
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raise ValueError(
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f"Geometry file must have exactly 10 bands (got {n_bands}): "
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"path length, VAA, VZA, SAA, SZA, phase, slope, aspect, cos i, UTC."
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)
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vaa = data[:, :, 1].copy()
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vza = data[:, :, 2].copy()
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saa = data[:, :, 3].copy()
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sza = data[:, :, 4].copy()
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raa = relative_azimuth_olci(saa, vaa)
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return {
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'sza': sza,
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'saa': saa,
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'vza': vza,
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'vaa': vaa,
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'raa': raa,
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}
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def read_water_mask(filepath):
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"""Read a single-band GeoTIFF water mask.
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Parameters
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----------
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filepath : str
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Path to the GeoTIFF file.
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Returns
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-------
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mask : ndarray, shape (rows, cols), int8
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Pixels with value 1 indicate water; all other values are non-water.
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"""
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with rasterio.open(filepath) as src:
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mask = src.read(1).astype(np.int8)
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return mask
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def _block_windows(src, block_size=512):
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"""Yield raster windows for block-wise processing."""
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rows, cols = src.height, src.width
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for row in range(0, rows, block_size):
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row_end = min(row + block_size, rows)
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for col in range(0, cols, block_size):
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col_end = min(col + block_size, cols)
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window = Window(col, row, col_end - col, row_end - row)
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yield window
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def _resolve_output_envi_path(output_file):
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"""Return the ENVI image path used for rasterio writes."""
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if output_file.lower().endswith(".img"):
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return output_file
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if output_file.lower().endswith(".hdr"):
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return output_file[:-4] + ".img"
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return output_file + ".img"
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def _read_wavelengths_from_header(hyperspectral_file):
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"""Read wavelength metadata from ENVI header if available."""
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img = spectral.open_image(_resolve_envi_header(hyperspectral_file))
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if hasattr(img, 'bands') and img.bands.centers is not None:
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wavelengths = img.bands.centers
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else:
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wavelengths = img.metadata.get('wavelength')
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if wavelengths is None:
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return None
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return np.asarray(wavelengths, dtype=np.float32)
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def save_brdf_result(
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ds_out,
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output_file,
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source_file=None,
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output_var="Rw_brdf",
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output_format="ENVI",
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dtype=np.float32,
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):
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"""Save the BRDF result to ENVI or NetCDF."""
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output_format = output_format.upper()
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if output_var not in ds_out:
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raise KeyError(f"Output variable '{output_var}' not found in result dataset.")
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if output_format == "NETCDF":
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if not output_file.lower().endswith(".nc"):
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output_file = output_file + ".nc"
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ds_out.to_netcdf(output_file)
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return output_file
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if output_format != "ENVI":
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raise ValueError("output_format must be 'ENVI' or 'NETCDF'.")
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cube = np.asarray(ds_out[output_var].values, dtype=dtype)
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cube = np.transpose(cube, (1, 2, 0))
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if output_file.lower().endswith(".hdr"):
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hdr_path = output_file
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else:
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hdr_path = output_file + ".hdr"
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metadata = {
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"interleave": "bsq",
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"description": f"BRDF corrected result: {output_var}",
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"bands": cube.shape[2],
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"lines": cube.shape[0],
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"samples": cube.shape[1],
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}
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if "bands" in ds_out.coords:
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metadata["wavelength"] = [str(v) for v in ds_out.coords["bands"].values.tolist()]
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if source_file is not None:
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metadata["source_file"] = source_file
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spectral.envi.save_image(
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hdr_path,
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cube,
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dtype=dtype,
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interleave="bsq",
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metadata=metadata,
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force=True,
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)
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return hdr_path
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def _get_output_filename(base_output_file: str, var_name: str) -> str:
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"""Generate output filename with variable suffix.
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Examples:
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input.hdr + Rw_brdf -> input_Rw_brdf.hdr
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input.hdr + brdf_unc -> input_brdf_unc.hdr
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"""
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base, ext = os.path.splitext(base_output_file)
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if ext.lower() in ('.hdr', '.img'):
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base = base # keep base without extension
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suffix = f"_{var_name}" if var_name.lower() != "rw_brdf" else ""
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return f"{base}{suffix}{ext}"
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def save_multiple_brdf_results(
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ds_out,
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output_file,
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source_file=None,
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output_vars=None,
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output_format="ENVI",
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dtype=np.float32,
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):
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"""Save multiple output variables to separate files."""
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if output_vars is None or len(output_vars) == 0:
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output_vars = ["Rw_brdf"]
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saved_files = []
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for var in output_vars:
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out_file = _get_output_filename(output_file, var)
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try:
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saved_path = save_brdf_result(
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ds_out=ds_out,
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output_file=out_file,
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source_file=source_file,
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output_var=var,
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output_format=output_format,
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dtype=dtype,
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)
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saved_files.append((var, saved_path))
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print(f" Saved {var} to: {saved_path}")
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except KeyError as e:
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print(f" Warning: {e}. Skipping {var}.")
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return saved_files
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def run_brdf_correction_block(
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hyperspectral_file,
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angle_file,
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output_file,
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mask_file=None,
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wavelengths=None,
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brdf_model='L11',
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output_vars=None, # 支持列表
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block_size=512,
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compute_uncertainty=False,
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progress_bar=True,
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):
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"""
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Run BRDF correction block-wise and write multiple variables to separate ENVI files.
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``angle_file`` must be a 10-band raster (same grid as hyperspectral); RAA is derived
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from bands 2 (VAA) and 4 (SAA); see :func:`read_bip_angles` for band order.
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If ``mask_file`` is None, every pixel is corrected (full scene); otherwise only pixels
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with mask value 1 are corrected (other pixels pass through unchanged for Rw_brdf).
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"""
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if output_vars is None:
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output_vars = ["Rw_brdf"]
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if isinstance(output_vars, str):
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output_vars = [output_vars]
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# 1. Open all inputs
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src_rw = rasterio.open(hyperspectral_file)
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n_bands = src_rw.count
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n_rows = src_rw.height
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n_cols = src_rw.width
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src_ang = rasterio.open(angle_file)
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if src_ang.height != n_rows or src_ang.width != n_cols:
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raise ValueError("Angle file dimensions do not match hyperspectral file.")
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if src_ang.count != 10:
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raise ValueError(
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f"Geometry file must have 10 bands (got {src_ang.count}). "
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"Expected: path length, VAA, VZA, SAA, SZA, phase, slope, aspect, cos i, UTC."
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)
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use_mask = mask_file is not None
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src_mask = rasterio.open(mask_file) if use_mask else None
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if use_mask and (src_mask.height != n_rows or src_mask.width != n_cols):
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raise ValueError("Mask file dimensions do not match hyperspectral file.")
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# 2. Wavelengths
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if wavelengths is None:
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wavelengths = _read_wavelengths_from_header(hyperspectral_file)
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if wavelengths is None:
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wavelengths = np.arange(1, n_bands + 1, dtype=np.float32)
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bands_xr = xr.DataArray(wavelengths, dims=('bands',), coords={'bands': wavelengths}, name='bands')
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# 3. Prepare multiple output files (one per variable)
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out_meta = src_rw.meta.copy()
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out_meta.update({
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'driver': 'ENVI',
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'dtype': 'float32',
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'count': n_bands,
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'interleave': 'bsq',
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})
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# Open one output file for each variable
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output_dsts = {}
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output_paths = {}
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for var_name in output_vars:
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var_file = _get_output_filename(output_file, var_name)
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out_path = _resolve_output_envi_path(var_file)
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output_dsts[var_name] = rasterio.open(out_path, 'w', **out_meta)
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output_paths[var_name] = out_path
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print(f" Writing {var_name} to {out_path}")
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# 4. Band indices in geometry file (1-based); RAA computed from SAA and VAA
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band_vaa = 2
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band_vza = 3
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band_saa = 4
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band_sza = 5
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# 5. Map output_var to ds_corr field (support uncertainty variables)
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var_map = {
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'Rw_brdf': 'rho_ex_w',
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'rho_ex_w': 'rho_ex_w',
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'nrrs': 'nrrs',
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'C_brdf': 'C_brdf',
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'brdf_unc': 'brdf_unc',
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'nrrs_unc': 'nrrs_unc',
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}
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# Validate all requested output variables
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for v in output_vars:
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if v not in var_map and v not in ['Rw_brdf']:
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raise ValueError(
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f"Unknown output_var '{v}'. Allowed: {list(var_map.keys())}"
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)
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# 6. Progress bar setup
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iterator = _block_windows(src_rw, block_size=block_size)
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if progress_bar and tqdm is not None:
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total_blocks = ((n_rows + block_size - 1) // block_size) * ((n_cols + block_size - 1) // block_size)
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iterator = tqdm(iterator, total=total_blocks, desc="Processing blocks", unit="block")
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elif progress_bar:
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print("Warning: tqdm not installed, progress bar disabled.")
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# Statistics for performance monitoring
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blocks_processed = 0
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blocks_skipped = 0
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total_corrected_pixels = 0
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# 7. Block-wise processing with early filtering
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for window in iterator:
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# Step 1: Read mask FIRST to enable early exit for pure land blocks (mask mode only)
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if use_mask:
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mask_block = src_mask.read(1, window=window).astype(np.int8)
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water_mask = (mask_block == 1)
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else:
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mask_block = None
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water_mask = np.ones((window.height, window.width), dtype=bool)
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n_water = np.count_nonzero(water_mask)
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if n_water == 0:
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# Fast path: pure land/no-water block - minimal processing (only when mask is used)
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blocks_skipped += 1
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# Still need to read hyperspectral for Rw_brdf output, but skip angles
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rw_block = src_rw.read(window=window).astype(np.float32)
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output_blocks = {}
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for var_name in output_vars:
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if var_name == 'Rw_brdf':
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output_blocks[var_name] = rw_block.copy()
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else:
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output_blocks[var_name] = np.full_like(rw_block, np.nan, dtype=np.float32)
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for var_name, block_data in output_blocks.items():
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output_dsts[var_name].write(block_data, window=window)
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del rw_block, water_mask
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gc.collect()
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continue
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# Step 2: Has water pixels - full processing
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blocks_processed += 1
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total_corrected_pixels += n_water
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# Read remaining data only for blocks that need processing
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rw_block = src_rw.read(window=window).astype(np.float32)
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sza_block = src_ang.read(band_sza, window=window).astype(np.float32)
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vza_block = src_ang.read(band_vza, window=window).astype(np.float32)
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saa_block = src_ang.read(band_saa, window=window).astype(np.float32)
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vaa_block = src_ang.read(band_vaa, window=window).astype(np.float32)
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raa_block = relative_azimuth_olci(saa_block, vaa_block)
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water_idx = np.where(water_mask)
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# Prepare output blocks for all variables
|
||
output_blocks = {}
|
||
for var_name in output_vars:
|
||
if var_name == 'Rw_brdf':
|
||
output_blocks[var_name] = rw_block.copy()
|
||
else:
|
||
output_blocks[var_name] = np.full_like(rw_block, np.nan, dtype=np.float32)
|
||
|
||
# Process water pixels
|
||
rw_water = rw_block[:, water_idx[0], water_idx[1]].T # (n_water, bands)
|
||
sza_water = sza_block[water_idx]
|
||
vza_water = vza_block[water_idx]
|
||
raa_water = raa_block[water_idx]
|
||
|
||
pixel_ids = np.arange(n_water)
|
||
ds_block = xr.Dataset(
|
||
{
|
||
'Rw': xr.DataArray(rw_water, dims=('n', 'bands'), coords={'n': pixel_ids, 'bands': bands_xr}),
|
||
'sza': xr.DataArray(sza_water, dims='n', coords={'n': pixel_ids}),
|
||
'vza': xr.DataArray(vza_water, dims='n', coords={'n': pixel_ids}),
|
||
'raa': xr.DataArray(raa_water, dims='n', coords={'n': pixel_ids}),
|
||
}
|
||
)
|
||
|
||
ds_corr = brdf_prototype(
|
||
ds_block,
|
||
brdf_model=brdf_model,
|
||
compute_uncertainty=compute_uncertainty,
|
||
)
|
||
|
||
# Write each requested variable to the water pixels
|
||
for var_name in output_vars:
|
||
field_name = var_map.get(var_name, 'rho_ex_w')
|
||
if var_name == 'Rw_brdf':
|
||
field_name = 'rho_ex_w'
|
||
if field_name in ds_corr:
|
||
values = ds_corr[field_name].values.T
|
||
output_blocks[var_name][:, water_idx[0], water_idx[1]] = values
|
||
|
||
# Write all variables for this block
|
||
for var_name, block_data in output_blocks.items():
|
||
output_dsts[var_name].write(block_data, window=window)
|
||
|
||
del (rw_block, sza_block, vza_block, saa_block, vaa_block, raa_block,
|
||
output_blocks, water_mask, water_idx, rw_water, sza_water, vza_water,
|
||
raa_water, pixel_ids, ds_block, ds_corr)
|
||
if mask_block is not None:
|
||
del mask_block
|
||
gc.collect()
|
||
|
||
# Close all files
|
||
src_rw.close()
|
||
src_ang.close()
|
||
if src_mask is not None:
|
||
src_mask.close()
|
||
for dst in output_dsts.values():
|
||
dst.close()
|
||
|
||
# Print performance statistics
|
||
total_blocks = blocks_processed + blocks_skipped
|
||
if total_blocks > 0:
|
||
skip_ratio = blocks_skipped / total_blocks * 100
|
||
print(f"Block processing completed:")
|
||
print(f" - Total blocks: {total_blocks}")
|
||
print(f" - Processed blocks (corrected): {blocks_processed}")
|
||
print(f" - Skipped blocks (no mask pixels): {blocks_skipped} ({skip_ratio:.1f}%)")
|
||
print(f" - Total pixels BRDF-corrected: {total_corrected_pixels:,}")
|
||
|
||
return list(output_paths.values())
|
||
|
||
|
||
# ---------------------------------------------------------------------------
|
||
# Top-level pipeline
|
||
# ---------------------------------------------------------------------------
|
||
def brdf_uncertainty(ds, adf=None):
|
||
''' Compute uncertainty of BRDF factor and propagate to nrrs '''
|
||
|
||
# Read LUT
|
||
if adf is None:
|
||
adf = ADF_OCP
|
||
|
||
unc_lut_path = adf % 'UNC'
|
||
if unc_lut_path not in UNC_LUT_CACHE:
|
||
UNC_LUT_CACHE[unc_lut_path] = xr.open_dataset(unc_lut_path, engine='netcdf4')
|
||
LUT = UNC_LUT_CACHE[unc_lut_path]
|
||
|
||
# Interpolate relative uncertainty
|
||
unc = LUT['unc'].interp(lambda_unc=ds.bands, theta_s_unc=ds.sza, theta_v_unc=ds.vza,
|
||
delta_phi_unc=ds.raa)
|
||
|
||
# Compute absolute uncertainty of factor
|
||
ds['brdf_unc'] = unc * ds['C_brdf']
|
||
|
||
# Flag BRDF_unc where NaN and set to 0
|
||
ds['brdf_unc_fail'] = np.isnan(ds['brdf_unc'])
|
||
ds['brdf_unc'] = xr.where(ds['brdf_unc_fail'], 0, ds['brdf_unc'])
|
||
|
||
# Propagate to nrrs
|
||
Rwex_unc2 = ds['brdf_unc'] * ds['brdf_unc'] * ds['Rw'] * ds['Rw']
|
||
if 'Rw_unc' in ds:
|
||
Rwex_unc2 += ds['C_brdf'] * ds['C_brdf'] * ds['Rw_unc'] * ds['Rw_unc']
|
||
ds['nrrs_unc'] = np.sqrt(Rwex_unc2)/np.pi
|
||
|
||
return ds
|
||
|
||
|
||
def brdf_prototype(ds, adf=None, brdf_model='L11', compute_uncertainty=True):
|
||
# 测试 BRDF 模型在 GUI 中不支持：强制覆盖
|
||
# brdf_model = 'M02SeaDAS'
|
||
|
||
# 压缩单一维度（例如，投放次数、提取次数等）以避免插值问题
|
||
ds, squeezedDims = squeeze_trivial_dims(ds)
|
||
|
||
# Initialise model
|
||
if brdf_model == 'M02':
|
||
BRDF_model = M02(bands=ds.bands, aot=ds.aot, wind=ds.wind, adf=None) # Don't use brdf_py.ADF context
|
||
elif brdf_model == 'M02SeaDAS':
|
||
BRDF_model = M02SeaDAS(bands=ds.bands, adf=None) # Don't use brdf_py.ADF context
|
||
elif brdf_model == 'L11':
|
||
BRDF_model = L11(bands=ds.bands, adf=None) # Don't use brdf_py.ADF context
|
||
elif brdf_model == 'O25':
|
||
BRDF_model = O25(bands=ds.bands, adf=None) # Don't use brdf_py.ADF context
|
||
else:
|
||
print("BRDF model %s not supported" % brdf_model)
|
||
sys.exit(1)
|
||
|
||
# Init pixel
|
||
BRDF_model.init_pixels(ds['sza'], ds['vza'], ds['raa'])
|
||
|
||
# Compute IOP and normalize by iterating
|
||
ds['nrrs'] = ds['Rw'] / np.pi
|
||
|
||
ds['convergeFlag'] = (0 * ds['sza']).astype(bool)
|
||
ds['C_brdf'] = 0 * ds['nrrs'] + 1
|
||
|
||
for iter_brdf in range(int(BRDF_model.niter)):
|
||
|
||
# M02: Initialise chl_iter
|
||
if brdf_model in ['M02', 'M02SeaDAS'] and (iter_brdf == 0):
|
||
chl_iter = {}
|
||
ds['log10_chl'] = 0 * ds['sza'] + float(np.log10(BRDF_model.OC4MEchl0))
|
||
chl_iter[-1] = 0 * ds['sza'] + float(BRDF_model.OC4MEchl0)
|
||
|
||
ds = BRDF_model.backward(ds, iter_brdf)
|
||
|
||
# M02: Check convergence (dummy for M02SeaDAS for the moment... epsilon set to 0)
|
||
if brdf_model in ['M02', 'M02SeaDAS']:
|
||
chl_iter[iter_brdf] = 10 ** ds['log10_chl']
|
||
# Check if convergence is reached |chl_old-chl_new| < epsilon * chl_new
|
||
ds['convergeFlag'] = (ds['convergeFlag']) | (
|
||
(np.abs(chl_iter[iter_brdf - 1] - chl_iter[iter_brdf]) < float(BRDF_model.OC4MEepsilon) * chl_iter[
|
||
iter_brdf]))
|
||
|
||
# Apply forward model in both geometries
|
||
forward_mod = BRDF_model.forward(ds)
|
||
forward_mod0 = BRDF_model.forward(ds, normalized=True)
|
||
|
||
ratio = forward_mod0 / forward_mod
|
||
|
||
# Drop remnant coordinates to avoid ambiguities in the update of the BRDF factor.
|
||
for coord in ratio.coords:
|
||
if coord not in ds['C_brdf'].coords:
|
||
ratio = ratio.drop(coord)
|
||
|
||
# Normalize reflectance
|
||
ds['C_brdf'] = xr.where(ds['convergeFlag'], ds['C_brdf'], ratio)
|
||
ds['nrrs'] = ds['Rw'] / np.pi * ds['C_brdf']
|
||
|
||
# Flag BRDF where NaN and set to 1 (no correction applied).
|
||
ds['C_brdf_fail'] = np.isnan(ds['C_brdf'])
|
||
ds['C_brdf'] = xr.where(ds['C_brdf_fail'], 1, ds['C_brdf'])
|
||
ds['nrrs'] = xr.where(ds['C_brdf_fail'], ds['Rw'] / np.pi, ds['nrrs'])
|
||
|
||
# If QAA_fail is raised, raise C_brdf_fail (but still apply C_brdf).
|
||
if 'QAA_fail' in ds:
|
||
ds['C_brdf_fail'] = (ds['C_brdf_fail']) | (ds['QAA_fail'])
|
||
|
||
# Compute uncertainty only if requested
|
||
if compute_uncertainty:
|
||
ds = brdf_uncertainty(ds)
|
||
|
||
# Compute flag
|
||
ds['flags_level2'] = ds['Rw'] * 0 # TODO
|
||
|
||
# Convert to reflectance unit
|
||
ds['rho_ex_w'] = ds['nrrs'] * np.pi
|
||
|
||
# Expand squeezed trivial dimensions
|
||
for dim,d0 in squeezedDims.items():
|
||
ds = ds.expand_dims(dim,axis=d0)
|
||
|
||
return ds
|
||
|
||
|
||
def run_brdf_correction(
|
||
hyperspectral_file,
|
||
angle_file,
|
||
mask_file=None,
|
||
wavelengths=None,
|
||
brdf_model='L11',
|
||
chunk_size=4096,
|
||
output_var=None, # if None, keep full output (original behaviour)
|
||
compute_uncertainty=True, # compute uncertainty only if requested
|
||
progress_bar=True, # 是否显示进度条
|
||
):
|
||
"""BRDF correction pipeline for water pixels in a hyperspectral scene.
|
||
|
||
``angle_file`` must be a 10-band ENVI geometry cube (see :func:`read_bip_angles`);
|
||
relative azimuth is computed from to-sun and to-sensor azimuths.
|
||
|
||
If ``mask_file`` is None, a mask of all ones is used (full-scene correction).
|
||
"""
|
||
# ------------------------------------------------------------------
|
||
# 1. Read all inputs
|
||
# ------------------------------------------------------------------
|
||
rw_data, wvl, _img_meta = read_bsq(hyperspectral_file, wavelengths, dtype=np.float32)
|
||
angles = read_bip_angles(angle_file, dtype=np.float32)
|
||
|
||
n_bands, n_rows, n_cols = rw_data.shape
|
||
|
||
if mask_file is None:
|
||
water_mask = np.ones((n_rows, n_cols), dtype=np.int8)
|
||
else:
|
||
water_mask = read_water_mask(mask_file)
|
||
|
||
# Sanity-check spatial dimensions
|
||
if angles['sza'].shape != (n_rows, n_cols):
|
||
raise ValueError(
|
||
f"Angle file spatial shape {angles['sza'].shape} does not match "
|
||
f"hyperspectral image shape ({n_rows}, {n_cols})."
|
||
)
|
||
if water_mask.shape != (n_rows, n_cols):
|
||
raise ValueError(
|
||
f"Mask shape {water_mask.shape} does not match "
|
||
f"hyperspectral image shape ({n_rows}, {n_cols})."
|
||
)
|
||
|
||
# ------------------------------------------------------------------
|
||
# 2. Identify water pixels
|
||
# ------------------------------------------------------------------
|
||
water_rows, water_cols = np.where(water_mask == 1)
|
||
n_water = water_rows.size
|
||
if n_water == 0:
|
||
raise RuntimeError("No water pixels found in the mask (no pixels == 1).")
|
||
|
||
# ------------------------------------------------------------------
|
||
# 3. Determine which output variable(s) we need to keep
|
||
# ------------------------------------------------------------------
|
||
# If output_var is None, we keep everything (original behaviour)
|
||
keep_all = (output_var is None)
|
||
|
||
# Map output_var to the field in ds_corr
|
||
var_map = {
|
||
'Rw_brdf': 'rho_ex_w',
|
||
'rho_ex_w': 'rho_ex_w',
|
||
'nrrs': 'nrrs',
|
||
'C_brdf': 'C_brdf'
|
||
}
|
||
if not keep_all:
|
||
if output_var not in var_map:
|
||
raise ValueError(f"Unknown output_var '{output_var}'. Allowed: {list(var_map.keys())}")
|
||
field_name = var_map[output_var]
|
||
else:
|
||
field_name = None
|
||
|
||
# ------------------------------------------------------------------
|
||
# 4. Allocate output arrays (only those needed)
|
||
# ------------------------------------------------------------------
|
||
shape3 = (n_bands, n_rows, n_cols)
|
||
shape2 = (n_rows, n_cols)
|
||
|
||
if keep_all:
|
||
# Original behaviour: allocate all arrays
|
||
nrrs_full = np.full(shape3, np.nan, dtype=np.float32)
|
||
rho_ex_w_full = np.full(shape3, np.nan, dtype=np.float32)
|
||
C_brdf_full = np.full(shape3, np.nan, dtype=np.float32)
|
||
brdf_unc_full = np.full(shape3, np.nan, dtype=np.float32)
|
||
nrrs_unc_full = np.full(shape3, np.nan, dtype=np.float32)
|
||
C_brdf_fail_full = np.zeros(shape2, dtype=bool)
|
||
rw_brdf_full = rw_data.copy()
|
||
else:
|
||
# Only allocate the requested output array
|
||
output_full = np.full(shape3, np.nan, dtype=np.float32)
|
||
# We may also need C_brdf_fail if requested? Not for output_var, but could be used internally? Skip.
|
||
# For simplicity, we do not allocate extra arrays.
|
||
|
||
# ------------------------------------------------------------------
|
||
# 5–6. Chunked BRDF correction
|
||
# ------------------------------------------------------------------
|
||
n_chunks = int(np.ceil(n_water / chunk_size))
|
||
|
||
# 初始化进度条
|
||
iterator = range(n_chunks)
|
||
if progress_bar and tqdm is not None:
|
||
iterator = tqdm(iterator, desc="Processing chunks", unit="chunk")
|
||
elif progress_bar:
|
||
print("Warning: tqdm not installed, progress bar disabled.")
|
||
|
||
for chunk_idx in iterator:
|
||
lo = chunk_idx * chunk_size
|
||
hi = min(lo + chunk_size, n_water)
|
||
|
||
rows_c = water_rows[lo:hi]
|
||
cols_c = water_cols[lo:hi]
|
||
|
||
# Extract batch vectors
|
||
rw_c = rw_data[:, rows_c, cols_c].T # (chunk, bands)
|
||
sza_c = angles['sza'][rows_c, cols_c] # (chunk,)
|
||
vza_c = angles['vza'][rows_c, cols_c]
|
||
raa_c = angles['raa'][rows_c, cols_c]
|
||
|
||
pixel_idx_c = np.arange(hi - lo)
|
||
ds_chunk = xr.Dataset(
|
||
{
|
||
'Rw': xr.DataArray(rw_c, dims=('n', 'bands'),
|
||
coords={'n': pixel_idx_c, 'bands': wvl}),
|
||
'sza': xr.DataArray(sza_c, dims='n',
|
||
coords={'n': pixel_idx_c}),
|
||
'vza': xr.DataArray(vza_c, dims='n',
|
||
coords={'n': pixel_idx_c}),
|
||
'raa': xr.DataArray(raa_c, dims='n',
|
||
coords={'n': pixel_idx_c}),
|
||
}
|
||
)
|
||
|
||
# Run BRDF model with uncertainty control
|
||
ds_corr = brdf_prototype(ds_chunk, brdf_model=brdf_model, compute_uncertainty=compute_uncertainty)
|
||
|
||
if keep_all:
|
||
# Write all results back
|
||
nrrs_full[:, rows_c, cols_c] = ds_corr['nrrs'].values.T
|
||
rho_ex_w_full[:, rows_c, cols_c] = ds_corr['rho_ex_w'].values.T
|
||
C_brdf_full[:, rows_c, cols_c] = ds_corr['C_brdf'].values.T
|
||
if compute_uncertainty:
|
||
brdf_unc_full[:, rows_c, cols_c] = ds_corr['brdf_unc'].values.T
|
||
nrrs_unc_full[:, rows_c, cols_c] = ds_corr['nrrs_unc'].values.T
|
||
C_brdf_fail_full[rows_c, cols_c] = ds_corr['C_brdf_fail'].values
|
||
rw_brdf_full[:, rows_c, cols_c] = ds_corr['rho_ex_w'].values.T
|
||
else:
|
||
# Only write the requested output field
|
||
values = ds_corr[field_name].values.T
|
||
output_full[:, rows_c, cols_c] = values
|
||
|
||
# Release batch objects so GC can reclaim memory
|
||
del rw_c, sza_c, vza_c, raa_c, pixel_idx_c, ds_chunk, ds_corr
|
||
gc.collect()
|
||
|
||
# ------------------------------------------------------------------
|
||
# 7. Assemble full-scene output Dataset
|
||
# ------------------------------------------------------------------
|
||
full_coords = {'bands': wvl, 'y': np.arange(n_rows), 'x': np.arange(n_cols)}
|
||
dims3 = ('bands', 'y', 'x')
|
||
dims2 = ('y', 'x')
|
||
|
||
if keep_all:
|
||
# Original behaviour: return all variables
|
||
ds_out = xr.Dataset(
|
||
{
|
||
'Rw': xr.DataArray(rw_data, dims=dims3, coords=full_coords),
|
||
'Rw_brdf': xr.DataArray(rw_brdf_full, dims=dims3, coords=full_coords),
|
||
'nrrs': xr.DataArray(nrrs_full, dims=dims3, coords=full_coords),
|
||
'rho_ex_w': xr.DataArray(rho_ex_w_full, dims=dims3, coords=full_coords),
|
||
'C_brdf': xr.DataArray(C_brdf_full, dims=dims3, coords=full_coords),
|
||
'C_brdf_fail': xr.DataArray(C_brdf_fail_full, dims=dims2),
|
||
'water_mask': xr.DataArray(water_mask, dims=dims2),
|
||
'sza': xr.DataArray(angles['sza'], dims=dims2),
|
||
'saa': xr.DataArray(angles['saa'], dims=dims2),
|
||
'vza': xr.DataArray(angles['vza'], dims=dims2),
|
||
'vaa': xr.DataArray(angles['vaa'], dims=dims2),
|
||
'raa': xr.DataArray(angles['raa'], dims=dims2),
|
||
}
|
||
)
|
||
if compute_uncertainty:
|
||
ds_out['brdf_unc'] = xr.DataArray(brdf_unc_full, dims=dims3, coords=full_coords)
|
||
ds_out['nrrs_unc'] = xr.DataArray(nrrs_unc_full, dims=dims3, coords=full_coords)
|
||
else:
|
||
# Return only the requested output variable + geometry + mask
|
||
ds_out = xr.Dataset(
|
||
{
|
||
output_var: xr.DataArray(output_full, dims=dims3, coords=full_coords),
|
||
'Rw': xr.DataArray(rw_data, dims=dims3, coords=full_coords),
|
||
'water_mask': xr.DataArray(water_mask, dims=dims2),
|
||
'sza': xr.DataArray(angles['sza'], dims=dims2),
|
||
'saa': xr.DataArray(angles['saa'], dims=dims2),
|
||
'vza': xr.DataArray(angles['vza'], dims=dims2),
|
||
'vaa': xr.DataArray(angles['vaa'], dims=dims2),
|
||
'raa': xr.DataArray(angles['raa'], dims=dims2),
|
||
}
|
||
)
|
||
# If uncertainties were computed, we could add them optionally, but user didn't request them.
|
||
# For memory efficiency, we skip them here.
|
||
|
||
return ds_out
|
||
|
||
|
||
def process_brdf_files(
|
||
hyperspectral_file,
|
||
angle_file,
|
||
output_file,
|
||
mask_file=None,
|
||
wavelengths=None,
|
||
brdf_model="L11",
|
||
output_vars=None,
|
||
output_format="ENVI",
|
||
chunk_size=4096,
|
||
block_size=512,
|
||
compute_uncertainty=False,
|
||
progress_bar=True,
|
||
):
|
||
"""Run BRDF correction from input files and save multiple variables to separate files.
|
||
|
||
The geometry file must contain 10 bands as documented for :func:`read_bip_angles`.
|
||
If ``mask_file`` is None, the full scene is corrected (same as :func:`run_brdf_correction_block`).
|
||
"""
|
||
if output_format.upper() != "ENVI":
|
||
raise NotImplementedError("Only ENVI output format is supported in block-wise version.")
|
||
|
||
if output_vars is None:
|
||
output_vars = ["Rw_brdf"]
|
||
if isinstance(output_vars, str):
|
||
output_vars = [output_vars]
|
||
|
||
print(f"Computing BRDF correction with variables: {output_vars}")
|
||
print(f"Output base name: {output_file}")
|
||
|
||
saved_paths = run_brdf_correction_block(
|
||
hyperspectral_file=hyperspectral_file,
|
||
angle_file=angle_file,
|
||
mask_file=mask_file,
|
||
output_file=output_file,
|
||
wavelengths=wavelengths,
|
||
brdf_model=brdf_model,
|
||
output_vars=output_vars,
|
||
block_size=block_size,
|
||
compute_uncertainty=compute_uncertainty,
|
||
progress_bar=progress_bar,
|
||
)
|
||
return None, saved_paths
|
||
|
||
|
||
def main():
|
||
import argparse
|
||
|
||
parser = argparse.ArgumentParser(description="Water-region BRDF correction for hyperspectral data.")
|
||
parser.add_argument("hyperspectral_file", help="Input ENVI BSQ hyperspectral file or .hdr path.")
|
||
parser.add_argument(
|
||
"angle_file",
|
||
help="10-band ENVI geometry file or .hdr: path length, VAA, VZA, SAA, SZA, "
|
||
"phase, slope, aspect, cos i, UTC (RAA computed from VAA and SAA).",
|
||
)
|
||
parser.add_argument("output_file", help="Output path prefix. ENVI writes .hdr/.img, NetCDF writes .nc.")
|
||
parser.add_argument(
|
||
"--mask",
|
||
dest="mask_file",
|
||
default=None,
|
||
metavar="PATH",
|
||
help="Optional water mask GeoTIFF; pixels == 1 are corrected. "
|
||
"If omitted, BRDF correction is applied to the full image.",
|
||
)
|
||
parser.add_argument("--brdf-model", default="L11", choices=["L11", "M02", "M02SeaDAS", "O25"])
|
||
parser.add_argument("--output-var", nargs='+', default=["Rw_brdf"],
|
||
help="Output variables to save (one or more). "
|
||
"Supported: Rw_brdf, rho_ex_w, nrrs, C_brdf, brdf_unc, nrrs_unc. "
|
||
"Example: --output-var Rw_brdf nrrs brdf_unc")
|
||
parser.add_argument("--output-format", default="ENVI", choices=["ENVI"])
|
||
parser.add_argument("--chunk-size", type=int, default=4096,
|
||
help="Number of water pixels per processing batch (default: 4096).")
|
||
parser.add_argument("--block-size", type=int, default=512,
|
||
help="Spatial block size for block-wise processing (default: 512).")
|
||
parser.add_argument("--compute-uncertainty", action="store_true",
|
||
help="Compute BRDF uncertainty (may increase runtime and output size).")
|
||
parser.add_argument("--no-progress-bar", action="store_true",
|
||
help="Disable progress bar (useful for non-interactive environments).")
|
||
args = parser.parse_args()
|
||
|
||
progress_bar = not args.no_progress_bar
|
||
|
||
_ds_out, saved_paths = process_brdf_files(
|
||
hyperspectral_file=args.hyperspectral_file,
|
||
angle_file=args.angle_file,
|
||
mask_file=args.mask_file,
|
||
output_file=args.output_file,
|
||
brdf_model=args.brdf_model,
|
||
output_vars=args.output_var,
|
||
output_format=args.output_format,
|
||
chunk_size=args.chunk_size,
|
||
block_size=args.block_size,
|
||
compute_uncertainty=args.compute_uncertainty,
|
||
progress_bar=progress_bar,
|
||
)
|
||
|
||
if isinstance(saved_paths, list):
|
||
print(f"BRDF correction finished. Saved {len(saved_paths)} files:")
|
||
for path in saved_paths:
|
||
print(f" - {path}")
|
||
else:
|
||
print(f"BRDF correction finished. Saved to: {saved_paths}")
|
||
|
||
if __name__ == "__main__":
|
||
main() |