draw_bbox fails for grayscale images

[lgvaz]

🐛 Bug

draw_data contains the line: img = PIL.Image.fromarray(img). If the image is grayscale and in the format (h,w,1) (which is what icevision expects` it fails with the error:

TypeError: Cannot handle this data type: (1, 1, 1), |u1

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More info:
https://stackoverflow.com/questions/63367136/pil-typeerror-cannot-handle-this-data-type-1-1-1-u1

[lgvaz]

It seems draw_masks and draw_keypoints also use this logic, so they will all fail

[lgvaz]

in #807 i tried to squeeze the images into two channels - it works, but now the error has moved somewhere else, it complains because we're trying to draw a colored bbox into a grayscale image

https://stackoverflow.com/a/42322058/6772672

[FraPochetti]

Not relevant anymore.