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BRDF/Flexbrdf/hytools/brdf/universal.py
2026-04-10 16:46:45 +08:00

221 lines
8.7 KiB
Python

# -*- coding: utf-8 -*-
"""
HyTools: Hyperspectral image processing library
Copyright (C) 2021 University of Wisconsin
Authors: Adam Chlus, Zhiwei Ye, Philip Townsend.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, version 3 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
本模块包含用于计算和应用单一(“通用”)组乘法 BRDF 校正系数的函数。系数可以按飞行线计算,也可以跨多个飞行线计算。
"""
from itertools import product
from copy import deepcopy
import numpy as np
import ray
from scipy.optimize import minimize
from .kernels import calc_volume_kernel,calc_geom_kernel
from ..misc import progbar
from ..misc import update_brdf
from ..masks import mask_create
from ..plotting import universal_diagno_plot
def universal_brdf(actors,config_dict):
brdf_dict = config_dict['brdf']
if brdf_dict['grouped']:
actors = calc_universal_group(actors)
else:
_ = ray.get([a.do.remote(calc_universal_single) for a in actors])
if brdf_dict['diagnostic_plots']:
print('Exporting diagnostic plots.')
_ = ray.get([a.do.remote(universal_diagno_plot,config_dict) for a in actors])
def sample_kernels(hy_obj):
'''计算并采样 BRDF 核函数
'''
#Sample kernel images
geom_kernel = hy_obj.geom_kernel(hy_obj.brdf['geometric'],
b_r=hy_obj.brdf["b/r"],
h_b =hy_obj.brdf["h/b"])[hy_obj.mask['calc_brdf']]
vol_kernel = hy_obj.volume_kernel(hy_obj.brdf['volume'])[hy_obj.mask['calc_brdf']]
X = np.vstack([vol_kernel,geom_kernel,
np.ones(vol_kernel.shape)]).T
return X
def subsample_mask(hy_obj):
'''对计算掩膜进行子采样并更新
'''
if hy_obj.brdf['sample_perc'] < 1:
idx = np.array(np.where(hy_obj.mask['calc_brdf'])).T
idx_rand= idx[np.random.choice(range(len(idx)),
int(len(idx)*(1- hy_obj.brdf['sample_perc'])),
replace = False)].T
hy_obj.mask['calc_brdf'][idx_rand[0],idx_rand[1]] = False
def calc_universal_single(hy_obj):
'''逐条飞行线计算 BRDF 系数。
'''
subsample_mask(hy_obj)
X = sample_kernels(hy_obj)
hy_obj.brdf['coeffs'] = {}
for band_num,band in enumerate(hy_obj.bad_bands):
if ~band:
band = hy_obj.get_band(band_num,
corrections = hy_obj.corrections, mask='calc_brdf')
brdf_coeff = np.linalg.lstsq(X, band,rcond=None)[0].flatten().tolist()
hy_obj.brdf['coeffs'][band_num] = brdf_coeff
def calc_universal_group(actors):
'''使用所有飞行线的合并数据计算 BRDF 系数。
'''
_ = ray.get([a.do.remote(subsample_mask) for a in actors])
X = ray.get([a.do.remote(sample_kernels) for a in actors])
X = np.concatenate(X)
bad_bands = ray.get(actors[0].do.remote(lambda x: x.bad_bands))
corections = ray.get(actors[0].do.remote(lambda x: x.corrections))
coeffs = {}
for band_num,band in enumerate(bad_bands):
if ~band:
y = ray.get([a.get_band.remote(band_num,mask='calc_brdf',
corrections = corections) for a in actors])
y = np.concatenate(y)
coeffs[band_num] = np.linalg.lstsq(X, y)[0].flatten().tolist()
progbar(np.sum(~bad_bands[:band_num+1]),np.sum(~bad_bands))
print('\n')
# 更新 BRDF 系数
_ = ray.get([a.do.remote(update_brdf,{'key':'coeffs',
'value': coeffs}) for a in actors])
return actors
def apply_universal(hy_obj,data,dimension,index):
''' 对数据切片应用通用 BRDF 校正
参数:
hy_obj : Hytools 类对象。
data (np.ndarray): 数据切片。
index (int,list): 数据索引。
返回:
data (np.ndarray): BRDF 校正后的数据切片。
'''
if 'k_vol' not in hy_obj.ancillary:
hy_obj.ancillary['k_vol'] = hy_obj.volume_kernel(hy_obj.brdf['volume'])
if 'k_geom' not in hy_obj.ancillary:
hy_obj.ancillary['k_geom'] = hy_obj.geom_kernel(hy_obj.brdf['geometric'],
b_r=hy_obj.brdf["b/r"],
h_b =hy_obj.brdf["h/b"])
if ('k_vol_nadir' not in hy_obj.ancillary) or ('k_geom_nadir' not in hy_obj.ancillary):
solar_zn = hy_obj.brdf['solar_zn_norm_radians'] * np.ones((hy_obj.lines,hy_obj.columns))
hy_obj.ancillary['k_vol_nadir'] = calc_volume_kernel(0,solar_zn,
0,0,hy_obj.brdf['volume'])
hy_obj.ancillary['k_geom_nadir'] = calc_geom_kernel(0,solar_zn,
0,0,hy_obj.brdf['geometric'],
b_r=hy_obj.brdf["b/r"],
h_b =hy_obj.brdf["h/b"])
if 'apply_brdf' not in hy_obj.mask:
hy_obj.gen_mask(mask_create,'apply_brdf',hy_obj.brdf['apply_mask'])
brdf_bands = [int(x) for x in hy_obj.brdf['coeffs'].keys()]
fvol, fgeo, fiso = np.array([hy_obj.brdf['coeffs'][band] for band in hy_obj.brdf['coeffs'].keys()]).T
# 转换为浮点数
data = data.astype(np.float32)
if dimension == 'line':
brdf = fvol[:,np.newaxis]*hy_obj.ancillary['k_vol'][[index],:]
brdf+= fgeo[:,np.newaxis]*hy_obj.ancillary['k_geom'][[index],:]
brdf+= fiso[:,np.newaxis]
brdf_nadir = fvol[:,np.newaxis]*hy_obj.ancillary['k_vol_nadir'][[index],:]
brdf_nadir+= fgeo[:,np.newaxis]*hy_obj.ancillary['k_geom_nadir'][[index],:]
brdf_nadir+= fiso[:,np.newaxis]
correction_factor = brdf_nadir/brdf
correction_factor[:,~hy_obj.mask['apply_brdf'][index,:]] = 1
data[:,brdf_bands] = data[:,brdf_bands]*correction_factor.T
elif dimension == 'column':
brdf = fvol[np.newaxis,:]*hy_obj.ancillary['k_vol'][:,[index]]
brdf+= fgeo[np.newaxis,:]*hy_obj.ancillary['k_geom'][:,[index]]
brdf+= fiso[np.newaxis,:]
brdf_nadir = fvol[np.newaxis,:]*hy_obj.ancillary['k_vol_nadir'][:,[index]]
brdf_nadir+= fgeo[np.newaxis,:]*hy_obj.ancillary['k_geom_nadir'][:,[index]]
brdf_nadir+= fiso[np.newaxis,:]
correction_factor = brdf_nadir/brdf
correction_factor[~hy_obj.mask['apply_brdf'][:,index],:] = 1
data[:,brdf_bands] = data[:,brdf_bands]*correction_factor.T
elif dimension == 'band':
fvol, fgeo, fiso = hy_obj.brdf['coeffs'][index]
brdf = fvol*hy_obj.ancillary['k_vol']
brdf += fgeo*hy_obj.ancillary['k_geom']
brdf+=fiso
brdf_nadir = fvol*hy_obj.ancillary['k_vol_nadir']
brdf_nadir+= fgeo*hy_obj.ancillary['k_geom_nadir']
brdf_nadir+= fiso
correction_factor = brdf_nadir/brdf
correction_factor[~hy_obj.mask['apply_brdf']] = 1
data= data* correction_factor
elif dimension == 'chunk':
x1,x2,y1,y2 = index
brdf = fvol[np.newaxis,np.newaxis,:]*hy_obj.ancillary['k_vol'][y1:y2,x1:x2,np.newaxis]
brdf+= fgeo[np.newaxis,np.newaxis,:]*hy_obj.ancillary['k_geom'][y1:y2,x1:x2,np.newaxis]
brdf+= fiso[np.newaxis,np.newaxis,:]
brdf_nadir = fvol[np.newaxis,np.newaxis,:]*hy_obj.ancillary['k_vol_nadir'][y1:y2,x1:x2,np.newaxis]
brdf_nadir+= fgeo[np.newaxis,np.newaxis,:]*hy_obj.ancillary['k_geom_nadir'][y1:y2,x1:x2,np.newaxis]
brdf_nadir+= fiso[np.newaxis,np.newaxis,:]
correction_factor = brdf_nadir/brdf
correction_factor[~hy_obj.mask['apply_brdf'][y1:y2,x1:x2]] = 1
data[:,:,brdf_bands] = data[:,:,brdf_bands]*correction_factor
elif dimension == 'pixels':
y,x = index
brdf = fvol[np.newaxis,:]*hy_obj.ancillary['k_vol'][y,x,np.newaxis]
brdf+= fgeo[np.newaxis,:]*hy_obj.ancillary['k_geom'][y,x,np.newaxis]
brdf+= fiso[np.newaxis,:]
brdf_nadir = fvol[np.newaxis,:]*hy_obj.ancillary['k_vol_nadir'][y,x,np.newaxis]
brdf_nadir+= fgeo[np.newaxis,:]*hy_obj.ancillary['k_geom_nadir'][y,x,np.newaxis]
brdf_nadir+= fiso[np.newaxis,:]
correction_factor = brdf_nadir/brdf
correction_factor[~hy_obj.mask['apply_brdf'][y,x]] = 1
data[:,brdf_bands] = data[:,brdf_bands]*correction_factor
return data