Python中栅格的5 X 5相邻像素的平均值

问题描述

我有像素分辨率为10 X 10米的倍数栅格，并且栅格值是float格式的，我只想将out栅格值保留为float格式。

我想计算5 x 5窗口像素平均，以消除图像中的噪声并在python中创建平滑的栅格。我从不同的stackoverflow来源研究了下面的代码，但是它不起作用并产生错误。

我将不胜感激。

下面的代码：

import time 
import glob
import os
import gdal
import osr
import numpy as np 

start_time_script = time.clock()

path_ras=r'D:\Firm_SM\F1A/'

for rasterfile in glob.glob(os.path.join(path_ras,'*.tif')):
    rasterfile_name=str(rasterfile[rasterfile.find('IMG'):rasterfile.find('.tif')])

print ('Processing:'+ ' ' + str(rasterfile_name))

ds = gdal.Open(rasterfile,gdal.GA_ReadOnly)
ds_xform = ds.GetGeoTransform()

print (ds_xform)

ds_driver = gdal.GetDriverByName('Gtiff')
srs = osr.SpatialReference()
#srs.ImportFromepsg(4726)

ds_array = ds.ReadAsArray()

sz = ds_array.itemsize

print ('This is the size of the neighbourhood:' + ' ' + str(sz))

h,w = ds_array.shape

print ('This is the size of the Array:' + ' ' + str(h) + ' ' + str(w))

bh,bw = 5,5

shape = (h/bh,w/bw,bh,bw)

print ('This is the new shape of the Array:' + ' ' + str(shape))

strides = sz*np.array([w*bh,bw,w,1])

blocks = np.lib.stride_tricks.as_strided(ds_array,shape=shape,strides=strides)

resized_array = ds_driver.Create(rasterfile_name + '_resized_to_52m.tif',shape[1],shape[0],1,gdal.GDT_Float32)
resized_array.SetGeoTransform((ds_xform[0],ds_xform[1]*2,ds_xform[2],ds_xform[3],ds_xform[4],ds_xform[5]*2))
resized_array.SetProjection(srs.ExportToWkt())
band = resized_array.GetRasterBand(1)

zero_array = np.zeros([shape[0],shape[1]],dtype=np.float32)

print ('I start calculations using neighbourhood')
start_time_blocks = time.clock()

for i in xrange(len(blocks)):
    for j in xrange(len(blocks[i])):

        zero_array[i][j] = np.mean(blocks[i][j])

print ('I finished calculations and I am going to write the new array')

band.WriteArray(zero_array)

end_time_blocks = time.clock() - start_time_blocks

print ('Image Processed for:' + ' ' + str(end_time_blocks) + 'seconds' + '\n')

end_time = time.clock() - start_time_script
print ('Program ran for: ' + str(end_time) + 'seconds')

错误信息：

This is the size of the neighbourhood: 4
This is the size of the Array: 106 144
This is the new shape of the Array: (21.2,28.8,5,5)
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-13-fbee5d0233b0> in <module>
     21 strides = sz*np.array([w*bh,1])
     22 
---> 23 blocks = np.lib.stride_tricks.as_strided(ds_array,strides=strides)
     24 
     25 resized_array = ds_driver.Create(rasterfile_name + '_resized_to_52m.tif',gdal.GDT_Float32)

c:\python37\lib\site-packages\numpy\lib\stride_tricks.py in as_strided(x,shape,strides,subok,writeable)
    101         interface['strides'] = tuple(strides)
    102 
--> 103     array = np.asarray(DummyArray(interface,base=x))
    104     # The route via `__interface__` does not preserve structured
    105     # dtypes. Since dtype should remain unchanged,we set it explicitly.

c:\python37\lib\site-packages\numpy\core\_asarray.py in asarray(a,dtype,order)
     83 
     84     """
---> 85     return array(a,copy=False,order=order)
     86 
     87 

TypeError: 'float' object cannot be interpreted as an integer

解决方法

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