dmlc / gluon-cv

Gluon CV Toolkit
http://gluon-cv.mxnet.io
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transform_test() - bug in original image output #1777

Closed ninafiona closed 7 months ago

ninafiona commented 11 months ago

When using the function load_test() or transform_test() there is a return value origs: "a numpy ndarray as original un-normalized color image for display." (see here: https://cv.gluon.ai/_modules/gluoncv/data/transforms/presets/yolo.html)

That image does not look like the original though, because it is resized with the "area-based" interpolation method. (see here: https://cv.gluon.ai/_modules/gluoncv/data/transforms/image.html#resize_short_within) With that method, values are outside of the 0-255 range and then, when astype('uint8') is applied, the image values over/underflow:

img = timage.resize_short_within(img, short, max_size, mult_base=stride)
orig_img = img.asnumpy().astype('uint8')

When applying functions afterwards, like gluoncv.utils.viz.plot_bbox(), the image looks incorrect at some spots.

github-actions[bot] commented 8 months ago

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