raster trace type: matplotlib imshow equivalent

Could/should we have some trace type that would be equivalent to matplotlib’s imshow() for showing full-color images? https://matplotlib.org/api/_as_gen/matplotlib.pyplot.imshow.html

basically heatmap but with r,g,b channels or something?

[YoniChechik]

@antoinerg , I think that a good line to follow is matplotlib.pyplot.imshow. Key functions not to be missed IMHO are:

• labeling (data on hover)
• aspect ratio! it’s very hard to set with bokeh the original image aspect ratio, or “equal” ratio, if needed.
• [0,0] origin: matlab and matplotlib both uses the origin as upper-left, which has since became standard.
• 2D and 3D (or 4D) input: 2D input should be like heatmap, with easy ability to change color limit min and max (default is data min and max). 3D/4D (RGB/A) input should be default to np.uint8 ([0,255]) or other types which will be in range [0,1].
• input array: must be able to take np.array and list of lists.

[alexcjohnson]

I’m for it - I really like the idea of being able to specify 3 (or 2 or 4) 2D arrays and specifying whether they’re RGB, HSV, HSL, or whatever. I had some instances in grad school of multiple independent 2D channels of data I wanted to overlay… never did find a mapping that was intelligible for 3 channels but for 2 channels either R+G, R+B, or L+H worked fairly well in my case.