Visualization support for single channel images #288
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frgfm
reviewed
Nov 13, 2024
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Thanks for the PR!
Good fix, let's only add one test to avoid regression and I added a comment to make this more robust. Could you add a test case here: https://github.com/frgfm/torch-cam/blob/main/tests/test_utils.py ?
torchcam/utils.py
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| if len(img.getbands()) == 1: | ||
| overlay = (255 * cmap(np.asarray(overlay) ** 2)[:, :, 0]).astype(np.uint8) | ||
| else: | ||
| overlay = (255 * cmap(np.asarray(overlay) ** 2)[:, :, :3]).astype(np.uint8) | ||
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Let's make this even more robust:
- the visualization can only work properly for single channel & 3 channel colormaps
- so let's raise an AssertionError if we don't have one of those two even before creating the
cmap. - since we're only doing broadcasting, I suggest to do:
overlay = (255 * cmap(np.asarray(overlay) ** 2)[:, :, :len(img.getbands())]).astype(np.uint8)There was a problem hiding this comment.
overlay = (255 * cmap(np.asarray(overlay) ** 2)[:, :, 2 if len(img.getbands())==1 else slice(0, 3)]).astype(np.uint8)
this will be more correct
frgfm
added
module: utils
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PR updated, test added |
frgfm
reviewed
Nov 19, 2024
frgfm
reviewed
Dec 10, 2024
| cmap = cm.get_cmap(colormap) | ||
| # Resize mask and apply colormap | ||
| overlay = mask.resize(img.size, resample=Resampling.BICUBIC) | ||
| overlay = (255 * cmap(np.asarray(overlay) ** 2)[:, :, :3]).astype(np.uint8) | ||
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| overlay = (255 * cmap(np.asarray(overlay) ** 2)[:, :, 2 if len(img.getbands()) == 1 else slice(0, 3)]).astype( |
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Final question: why taking the last channel, not first or second? Is any of those better for viz in grayscale? Or should we average accross the channel dimension?
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What does this PR do?
Added support for single channel images into overlay_mask