feature request: imshow() like matplotlib or cv2

[YoniChechik]

i'm familiar with go.layout.Image(), but it missing for me crucial "show closes data on hover" pixel RGB value + it can't show image from np.array.

I guess that the closest thing to start from when implementing this is heatmaps with the ability to control each pixel RGB value

it can really bring plotly to a lot more computer vision oriented programing (mainly in jupyter) and make plotly even better.

[jonmmease]

Hi @YoniChechik,

Yeah, this would be really nice. There's an open issue with the plotly.js project to add a native trace for doing this (plotly/plotly.js#3898).

One approach that I've thought of trying, but haven't yet, is overlaying a transparent heatmap on top of a layout.image. Heatmaps have an opacity property that can be set to 0 while still preserving tooltips. If this was a helpful approach, we could automate it as a figure factory or plotly express utility until plotly.js adds native support.

One downside, though, is that the pixels of a layout.image object are smoothed. So you don't get the crisp heatmap-style pixel boundaries when you zoom in. But this might be something that could be addressed as a new option in plotly.js for layout.image objects.

Are you interested in investigating this approach?

[YoniChechik]

@jonmmease I'd be happy to help, but I no nothing about node js... The one input I can give is that the use of layout.image is wrong since the need of per-pixel separation is key! I think that changing the heatmap input to accept 3D arrays and choose each pixel color accordingly is the way to go

[jonmmease]

The one input I can give is that the use of layout.image is wrong since the need of per-pixel separation is key!

Yeah, I agree. So we'll need to wait for something to be added in the plotly.js layer.

[YoniChechik]

@jonmmease check this out: plotly/plotly.js#3898 plotly/plotly.js#4289

[nicolaskruchten]

Yep @YoniChechik we've designed image in plotly.js specifically to support this feature, which should come out in Plotly.py v4.3 :)