我有同样的问题，不同的数据。这是我编写的使用并行处理和滑动窗口方法的脚本：
import gdal, osr
import numpy as np
from scipy.interpolate import RectBivariateSpline
from numpy.lib.stride_tricks import as_strided as ast
import dask.array as da
from joblib import Parallel, delayed, cpu_count
import os
from skimage.feature import greycomatrix, greycoprops
def im_resize(im,Nx,Ny):
'''
resize array by bivariate spline interpolation
'''
ny, nx = np.shape(im)
xx = np.linspace(0,nx,Nx)
yy = np.linspace(0,ny,Ny)
try:
im = da.from_array(im, chunks=1000) #dask implementation
except:
pass
newKernel = RectBivariateSpline(np.r_[:ny],np.r_[:nx],im)
return newKernel(yy,xx)
def p_me(Z, win):
'''
loop to calculate greycoprops
'''
try:
glcm = greycomatrix(Z, [5], [0], 256, symmetric=True, normed=True)
cont = greycoprops(glcm, 'contrast')
diss = greycoprops(glcm, 'dissimilarity')
homo = greycoprops(glcm, 'homogeneity')
eng = greycoprops(glcm, 'energy')
corr = greycoprops(glcm, 'correlation')
ASM = greycoprops(glcm, 'ASM')
return (cont, diss, homo, eng, corr, ASM)
except:
return (0,0,0,0,0,0)
def read_raster(in_raster):
in_raster=in_raster
ds = gdal.Open(in_raster)
data = ds.GetRasterBand(1).ReadAsArray()
data[data<=0] = np.nan
gt = ds.GetGeoTransform()
xres = gt[1]
yres = gt[5]
# get the edge coordinates and add half the resolution
# to go to center coordinates
xmin = gt[0] + xres * 0.5
xmax = gt[0] + (xres * ds.RasterXSize) - xres * 0.5
ymin = gt[3] + (yres * ds.RasterYSize) + yres * 0.5
ymax = gt[3] - yres * 0.5
del ds
# create a grid of xy coordinates in the original projection
xx, yy = np.mgrid[xmin:xmax+xres:xres, ymax+yres:ymin:yres]
return data, xx, yy, gt
def norm_shape(shap):
'''
Normalize numpy array shapes so they're always expressed as a tuple,
even for one-dimensional shapes.
'''
try:
i = int(shap)
return (i,)
except TypeError:
# shape was not a number
pass
try:
t = tuple(shap)
return t
except TypeError:
# shape was not iterable
pass
raise TypeError('shape must be an int, or a tuple of ints')
def sliding_window(a, ws, ss = None, flatten = True):
'''
Source: http://www.johnvinyard.com/blog/?p=268#more-268
Parameters:
a - an n-dimensional numpy array
ws - an int (a is 1D) or tuple (a is 2D or greater) representing the size
of each dimension of the window
ss - an int (a is 1D) or tuple (a is 2D or greater) representing the
amount to slide the window in each dimension. If not specified, it
defaults to ws.
flatten - if True, all slices are flattened, otherwise, there is an
extra dimension for each dimension of the input.
Returns
an array containing each n-dimensional window from a
'''
if None is ss:
# ss was not provided. the windows will not overlap in any direction.
ss = ws
ws = norm_shape(ws)
ss = norm_shape(ss)
# convert ws, ss, and a.shape to numpy arrays
ws = np.array(ws)
ss = np.array(ss)
shap = np.array(a.shape)
# ensure that ws, ss, and a.shape all have the same number of dimensions
ls = [len(shap),len(ws),len(ss)]
if 1 != len(set(ls)):
raise ValueError(\
'a.shape, ws and ss must all have the same length. They were %s' % str(ls))
# ensure that ws is smaller than a in every dimension
if np.any(ws > shap):
raise ValueError(\
'ws cannot be larger than a in any dimension.\
a.shape was %s and ws was %s' % (str(a.shape),str(ws)))
# how many slices will there be in each dimension?
newshape = norm_shape(((shap - ws) // ss) + 1)
# the shape of the strided array will be the number of slices in each dimension
# plus the shape of the window (tuple addition)
newshape += norm_shape(ws)
# the strides tuple will be the array's strides multiplied by step size, plus
# the array's strides (tuple addition)
newstrides = norm_shape(np.array(a.strides) * ss) + a.strides
a = ast(a,shape = newshape,strides = newstrides)
if not flatten:
return a
# Collapse strided so that it has one more dimension than the window. I.e.,
# the new array is a flat list of slices.
meat = len(ws) if ws.shape else 0
firstdim = (np.product(newshape[:-meat]),) if ws.shape else ()
dim = firstdim + (newshape[-meat:])
# remove any dimensions with size 1
dim = filter(lambda i : i != 1,dim)
return a.reshape(dim), newshape
def CreateRaster(xx,yy,std,gt,proj,driverName,outFile):
'''
Exports data to GTiff Raster
'''
std = np.squeeze(std)
std[np.isinf(std)] = -99
driver = gdal.GetDriverByName(driverName)
rows,cols = np.shape(std)
ds = driver.Create( outFile, cols, rows, 1, gdal.GDT_Float32)
if proj is not None:
ds.SetProjection(proj.ExportToWkt())
ds.SetGeoTransform(gt)
ss_band = ds.GetRasterBand(1)
ss_band.WriteArray(std)
ss_band.SetNoDataValue(-99)
ss_band.FlushCache()
ss_band.ComputeStatistics(False)
del ds
#Stuff to change
if __name__ == '__main__':
win_sizes = [7]
for win_size in win_sizes[:]:
in_raster = #Path to input raster
win = win_size
meter = str(win/4)
#Define output file names
contFile =
dissFile =
homoFile =
energyFile =
corrFile =
ASMFile =
merge, xx, yy, gt = read_raster(in_raster)
merge[np.isnan(merge)] = 0
Z,ind = sliding_window(merge,(win,win),(win,win))
Ny, Nx = np.shape(merge)
w = Parallel(n_jobs = cpu_count(), verbose=0)(delayed(p_me)(Z[k]) for k in xrange(len(Z)))
cont = [a[0] for a in w]
diss = [a[1] for a in w]
homo = [a[2] for a in w]
eng = [a[3] for a in w]
corr = [a[4] for a in w]
ASM = [a[5] for a in w]
#Reshape to match number of windows
plt_cont = np.reshape(cont , ( ind[0], ind[1] ) )
plt_diss = np.reshape(diss , ( ind[0], ind[1] ) )
plt_homo = np.reshape(homo , ( ind[0], ind[1] ) )
plt_eng = np.reshape(eng , ( ind[0], ind[1] ) )
plt_corr = np.reshape(corr , ( ind[0], ind[1] ) )
plt_ASM = np.reshape(ASM , ( ind[0], ind[1] ) )
del cont, diss, homo, eng, corr, ASM
#Resize Images to receive texture and define filenames
contrast = im_resize(plt_cont,Nx,Ny)
contrast[merge==0]=np.nan
dissimilarity = im_resize(plt_diss,Nx,Ny)
dissimilarity[merge==0]=np.nan
homogeneity = im_resize(plt_homo,Nx,Ny)
homogeneity[merge==0]=np.nan
energy = im_resize(plt_eng,Nx,Ny)
energy[merge==0]=np.nan
correlation = im_resize(plt_corr,Nx,Ny)
correlation[merge==0]=np.nan
ASM = im_resize(plt_ASM,Nx,Ny)
ASM[merge==0]=np.nan
del plt_cont, plt_diss, plt_homo, plt_eng, plt_corr, plt_ASM
del w,Z,ind,Ny,Nx
driverName= 'GTiff'
epsg_code=26949
proj = osr.SpatialReference()
proj.ImportFromEPSG(epsg_code)
CreateRaster(xx, yy, contrast, gt, proj,driverName,contFile)
CreateRaster(xx, yy, dissimilarity, gt, proj,driverName,dissFile)
CreateRaster(xx, yy, homogeneity, gt, proj,driverName,homoFile)
CreateRaster(xx, yy, energy, gt, proj,driverName,energyFile)
CreateRaster(xx, yy, correlation, gt, proj,driverName,corrFile)
CreateRaster(xx, yy, ASM, gt, proj,driverName,ASMFile)
del contrast, merge, xx, yy, gt, meter, dissimilarity, homogeneity, energy, correlation, ASM
此脚本为定义的窗口大小计算 GLCM 属性，相邻窗口之间没有重叠。
