fossasia/visdom

Adding support for alpha channels

Open

#694 opened on Jan 2, 2020

View on GitHub
 (4 comments) (0 reactions) (0 assignees)Python (9,831 stars) (1,152 forks)batch import
enhancementhelp wanted

Description

Currently, this project supports displaying greyscale and RGB images. However, many digital images also contain an alpha channel, and it would be nice to display images as RGBA, rather than converting them to RGB.

My initial investigation shows that simply changing the depth of the first axis from 3 to 4 in https://github.com/facebookresearch/visdom/blob/master/py/visdom/__init__.py#L1268 allows for proper display of RGBA images. Grayscale and RGB images would need to be converted to RGBA by adding a 'full' alpha channel.

Changing only the line as described above, and setting the background of the windows to green gives the following result: image

Contributor guide

Tech stack
pythonnumpy
Domain
data
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
PythonNumPybasic git workflow
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
85
Research direction
The issue suggests modifying `py/visdom/ init .py` at line 1268 to change the depth of the first axis from 3 to 4. Additionally, grayscale and RGB images must be converted to RGBA by adding a full alpha channel. The existing code and image loading logic should be reviewed to ensure compatibility. No linked PRs or assignees, so the work is open.