Here, I have python code which is helping me in selecting 5 by 5 window from upper left corner of a raster (.tif). I want a process to automate through entire image in 5 by 5 convolution window.

import cv2
import numpy as np
from matplotlib import pyplot as plt 
img = cv2.imread('class.tif')
kernel = np.ones((5,5),np.float32)

How to loop the kernel which will cover all pixels from a raster in 5 by 5 convolution window for getting all pixel values in this convolution window? I don't want to generate another raster. I want location of abnormal values within each window after statistical tests. How is it possible?

closed as unclear what you're asking by xunilk, whyzar, Kersten, nmtoken, Vince Jan 14 '18 at 18:13

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • In a deleted former commentary you said: "I don't want to convert raster to an array..." but, I guess that you want all raster values in a 5x5 window from upper left corner of a raster (.tif) through entire image in 5x 5 window. I would like to know how will you accomplish this if you don't want to read raster values first. – xunilk Jan 13 '18 at 1:26
  • Sir, may be I am wrong but using "cv2" module I am able to read an image without converting it into an array . It is reading pixel values only. So I thought if someone has idea to modify it further and serve the purpose. Further, I don't mind in converting raster to an array but ultimately I need lat-lon of highlighted pixels . If you it is possible even after converting it into an array then I would happy to do that. @xunilk – vigna purohit Jan 13 '18 at 4:36
  • I voted this question for reopening but, why did you choose this cv2 python module? Did you read its documentation? If you print 'img', you will see that it is a very strange array (yes, an ARRAY!). If you had read the documentation, you would have seen the need to use flags for a good use of 'imread' method. – xunilk Jan 17 '18 at 13:39
  • I found out because you chose this amazing python module named cv2. I also found out how to loop the kernel for covering all pixels from a raster in 5 by 5 convolution window. – xunilk Jan 17 '18 at 22:55
  • Thank you for reopening sir. As i said I am not a python pro but I have to use it as I want automation in my thesis work. Yes, I had read the documentation and I found worth trying it. If you have better option suggest any other module to complete this task. Previously I was working with GDAL and nupy for all raster operations should I continue with it? @xunilk – vigna purohit Jan 18 '18 at 6:51