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How to remove specific shade of grey from a greyscale image in python PIL


How can I remove a trailing newline in Python?How do I remove an element from a list by index in Python?How do I trim whitespace from a Python string?How to remove items from a list while iterating?Remove specific characters from a string in PythonPIL convert('L') to greyscale distorts some imagesPython Image Library fails with message “decoder JPEG not available” - PILPython: Cannot open converted bitmap image file, converted using PILHow to remove a key from a Python dictionary?Replicating ImageMagicks 'Badge using Lighting Effects' using PIL






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0















I have a python PIL script that is turning an image into greyscale and then removing a specific shade of grey. I can do this by converting first to rgb and then removing the grey, but I'd like to only be in greyscale.



color = [149, 149, 149]
white = [255, 255, 255]
im2 = Image.open('example-files/step1.jpg')
im = im2.convert('RGB')
data = np.array(im)
rgb = data[:, :, :3]
mask = np.all(rgb == color, axis=-1)
data[mask] = white
new_im = Image.fromarray(data).convert('L')
new_im.save('example-files/step3.png')


This works, except I don't ever want to .convert('RGB'), I always want to remain in greyscale, as I want to make this as fast as possible and I found that that extra convert add about .04 seconds. I tried using the data[mask] method while in greyscale and it doesn't work:



color = [149]
white = [255]
im = Image.open('example-files/step1.jpg').convert('L')
data = np.array(im)
mask = np.all(data == color, axis=-1)
data[mask] = white
new_im = Image.fromarray(data)
new_im.save('example-files/step6.png')


What can I do to either remove that color of grey as fast as possible or get it to remove while remaining in greyscale?










share|improve this question




























    0















    I have a python PIL script that is turning an image into greyscale and then removing a specific shade of grey. I can do this by converting first to rgb and then removing the grey, but I'd like to only be in greyscale.



    color = [149, 149, 149]
    white = [255, 255, 255]
    im2 = Image.open('example-files/step1.jpg')
    im = im2.convert('RGB')
    data = np.array(im)
    rgb = data[:, :, :3]
    mask = np.all(rgb == color, axis=-1)
    data[mask] = white
    new_im = Image.fromarray(data).convert('L')
    new_im.save('example-files/step3.png')


    This works, except I don't ever want to .convert('RGB'), I always want to remain in greyscale, as I want to make this as fast as possible and I found that that extra convert add about .04 seconds. I tried using the data[mask] method while in greyscale and it doesn't work:



    color = [149]
    white = [255]
    im = Image.open('example-files/step1.jpg').convert('L')
    data = np.array(im)
    mask = np.all(data == color, axis=-1)
    data[mask] = white
    new_im = Image.fromarray(data)
    new_im.save('example-files/step6.png')


    What can I do to either remove that color of grey as fast as possible or get it to remove while remaining in greyscale?










    share|improve this question
























      0












      0








      0








      I have a python PIL script that is turning an image into greyscale and then removing a specific shade of grey. I can do this by converting first to rgb and then removing the grey, but I'd like to only be in greyscale.



      color = [149, 149, 149]
      white = [255, 255, 255]
      im2 = Image.open('example-files/step1.jpg')
      im = im2.convert('RGB')
      data = np.array(im)
      rgb = data[:, :, :3]
      mask = np.all(rgb == color, axis=-1)
      data[mask] = white
      new_im = Image.fromarray(data).convert('L')
      new_im.save('example-files/step3.png')


      This works, except I don't ever want to .convert('RGB'), I always want to remain in greyscale, as I want to make this as fast as possible and I found that that extra convert add about .04 seconds. I tried using the data[mask] method while in greyscale and it doesn't work:



      color = [149]
      white = [255]
      im = Image.open('example-files/step1.jpg').convert('L')
      data = np.array(im)
      mask = np.all(data == color, axis=-1)
      data[mask] = white
      new_im = Image.fromarray(data)
      new_im.save('example-files/step6.png')


      What can I do to either remove that color of grey as fast as possible or get it to remove while remaining in greyscale?










      share|improve this question














      I have a python PIL script that is turning an image into greyscale and then removing a specific shade of grey. I can do this by converting first to rgb and then removing the grey, but I'd like to only be in greyscale.



      color = [149, 149, 149]
      white = [255, 255, 255]
      im2 = Image.open('example-files/step1.jpg')
      im = im2.convert('RGB')
      data = np.array(im)
      rgb = data[:, :, :3]
      mask = np.all(rgb == color, axis=-1)
      data[mask] = white
      new_im = Image.fromarray(data).convert('L')
      new_im.save('example-files/step3.png')


      This works, except I don't ever want to .convert('RGB'), I always want to remain in greyscale, as I want to make this as fast as possible and I found that that extra convert add about .04 seconds. I tried using the data[mask] method while in greyscale and it doesn't work:



      color = [149]
      white = [255]
      im = Image.open('example-files/step1.jpg').convert('L')
      data = np.array(im)
      mask = np.all(data == color, axis=-1)
      data[mask] = white
      new_im = Image.fromarray(data)
      new_im.save('example-files/step6.png')


      What can I do to either remove that color of grey as fast as possible or get it to remove while remaining in greyscale?







      python numpy python-imaging-library






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked Mar 8 at 4:23









      EricEric

      1116




      1116






















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