enter image description hereHi I want to divide an image (200x200) into 100 blocks of equal sizes and then I want to find average of each block. I have looked around a lot on how to divide the image into 10x10 blocks(10 rows 10 columns) but not able to grasp the concept on how to do so. Can anyone help.
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I'll assume you have numpy, since you have it as a tag. If you don't have the Pillow module, run
pip install Pillow
and grab that. The following code will split the image into a 400 blocks of 10x10.
import numpy as np
from PIL import Image
image = Image.open("your_file.jpg", "r")
arr = np.asarray(image)
arr = np.split(arr, 20)
arr = np.array([np.split(x, 20, 1) for x in arr])
Then, to grab the i-j'th block, index into it via:
arr[i][j]
Daniel Nguyen
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Is it possible to get the average of each block? – Christina Evans Oct 10 '19 at 04:54
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arr[i][j].matrix.mean() should do the trick. @ChristinaEvans – Daniel Nguyen Oct 10 '19 at 04:58
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it gives an error that j is not defined – Christina Evans Oct 10 '19 at 05:01
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Try [arr[i][j].matrix.mean() for i in range(40) for j in range(40)] – Daniel Nguyen Oct 10 '19 at 05:03
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It gives an error 'numpy.ndarray' object has no attribute 'matrix' – Christina Evans Oct 10 '19 at 05:11
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Oops, try [arr[i][j].mean() for i in range(40) for j in range(40)] – Daniel Nguyen Oct 10 '19 at 05:19
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Thanks a lot. You are a life savor @Daniel – Christina Evans Oct 10 '19 at 05:23
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I have one more small question. Since we have 400 blocks shouldn't there be 400 mean values? I found the mean of each block and it shows that the length is 1600. – Christina Evans Oct 10 '19 at 05:45
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Yeah, my original post had an error. The 40 in my previous comments should be changed to a 20 with the updated code. My apologies. – Daniel Nguyen Oct 10 '19 at 06:19