Remove the black border and keep the image size same in python

Question

I am rotating an image 45 degree. When I rotate the image it has a black border and the image size changes from 256x256 to 364x364. I want to remove the values of this black border and keep the size 256. In pillow if I put fill color then the black border will go away but the size is still the same. Is there any way that I can remove the black border and retain the original shape

code to rotate

path = "E:\\download\\1.jpeg"
image = cv2.imread(path)
rotated = imutils.rotate_bound(image, -33)

Original Image

Rotate image

With what you want to replace the black border ? – David Jan 30 '22 at 21:09 — David, Jan 30 '22 at 21:09
just use opencv's warpAffine and getRotationMatrix2D – Christoph Rackwitz Jan 30 '22 at 21:47 — Christoph Rackwitz, Jan 30 '22 at 21:47

score 1 · Answer 1 · edited Jan 31 '22 at 00:30

1

Keeping the shape while rotating an image is simply not possible in the way you want to. Just like rotating a square-shaped sheet of paper, the horizontal width would enlarge when rotating by e.g. 45°. If you now crop the image on 256x256, you would obtain again black area in the image (see example below). So you would have too crop it even more or zoom in then.

Example of cropped image, click here

edited Jan 31 '22 at 00:30

Jeremy Caney

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answered Jan 30 '22 at 21:15

Soaring

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score 0 · Accepted Answer · edited Jan 30 '22 at 21:31

you can try to crop the image as much as part of the image you want. Although the cropping in python is possible in the form of pixels. Hence, you can try to crop the image as much is required. The following code might help you to crop

im=Image.open(r"specify the path of the image")`

width, height = im.size

left = "specify the value in pixels"
top = "specify the value in pixels"
right = "specify the value in pixels"
bottom = "specify the value in pixels"
# Cropped image of above dimension
# (It will not change original image)
im1 = im.crop((left, top, right, bottom))
#im1.show()
im1.save('specify destination path')

Remove the black border and keep the image size same in python

2 Answers2