Convert the annotations of thing to COCO instance format about panopticapi

[alexander-kirillov]

Hi Yun,

pan = pan_format[:,:,0] + 256 * pan_format[:,:,1] + 256*256*pan_format[:,:,2]
This line converts RGB values to IDs that encode different segments in panoptic COCO format. Please see, note 2 in panoptic segmentation section of COCO data format.

When I print the results after converting to the COCO instance format, it seems that there are all the binary encoding for the "segmentation" rather than the decimal code as the COCO instance format.

Original COCO segmentations are stored as polygons (decimal code represents their vertices) instance_data.py stores in the "segmentation" field RLE encoding of the corresponding mask. Note that COCO API supports the format as well as the polygon description. Current version of Detectron, however, does not support RLE encoded segments. There is a pull request you can use to add the support.

I hope this answers your question. Let me know if something else is not clear.

[karenyun]

Hi, thanks for your quick reply, I will read them carefully!

[karenyun]

Hi @alexander-kirillov,

Sorry to bother you again, when I make the PNG file I only know the color of different categories while for different segments which belong to the same class in the same image how to diff them in color format, I find in the gt_png file, it does not simple as changing the last channel. So I have some problems when making the "id" for every segment. Could you give some suggestions?

Thanks very much!

[karenyun]

Hi, I think I have known how to make it, thanks!

[alexander-kirillov]

Hi Shen,

In general, IDs are arbitrary. So you can assign any color to each segment except [0, 0, 0]. The only requirement - for different segments in the same image colors must be different.

If you want IDs that look nice, then there is a class ColorGenerator in format_converter.py script. This class allows to generate colors for segments so that they are similar to class color but each segment will have a unique color. I hope this helps in your case.

[karenyun]

got it, thanks!

[ranjiewwen]

Hi Shen,

In general, IDs are arbitrary. So you can assign any color to each segment except [0, 0, 0]. The only requirement - for different segments in the same image colors must be different.

If you want IDs that look nice, then there is a class ColorGenerator in format_converter.py script. This class allows to generate colors for segments so that they are similar to class color but each segment will have a unique color. I hope this helps in your case.

i also have some question:
#15