roboflow / roboflow/roboflow-python
Transparency (alpha) band of PNG images not used when training
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- Dominant language
- Python
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Description
A normal image is composed by red, green, and blue (RGB) channels. Some image format, like .png, allow to have 4, where the 4th usually it's the transparency of the image (this is called alpha channel sometimes). In most of our dataset, we exploit this extra channel to put an extra color information, the infrared band (since we use satellite images with 4 bands). When we upload PNG images with 4 bands, and then we download it back from roboflow, this information is lost, as the downloaded images have in the alpha band only 255 as value, and also the RGB values seems slightly modified.
I'm attaching to this email a link to a COCO dataset that can be uploaded to debug this problem: here
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by reproducing the issue with the linked COCO dataset and four-band PNG images, comparing the uploaded images with the downloaded results. Done means the downloaded PNGs preserve the alpha/infrared band values and do not unexpectedly modify the RGB channels.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- computer-vision
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 28/100