Incorrect padding in Market-1501 filenames on export

[archibald1418]

Based on CVAT docs and Datumaro docs

when exporting to Market-1508 format, Datumaro should save annotations to files with certain naming convention:

images_<any_subset_name>.txt

query/image_name_1.jpg
bounding_box_<any_subset_name>/image_name_2.jpg
bounding_box_<any_subset_name>/image_name_3.jpg

image_name = 0001_c1s1_000015_00.jpg

0001 - person id
c1 - camera id (there are totally 6 cameras)
s1 - sequence
000015 - frame number in sequence
00 - means that this bounding box is the first one among the several

but person_id is not being zero-padded on export.

Solution: add f'{pid:04d}'

Notes to consider

• Fixing this in CVAT could lead to ValueError: Unknown format code 'd' for object of type 'float'. Seems that values of label attributes with {"input_type":"number"} turn into floats inside DatasetItem.attributes, need to investigate. Likely culprit is Datumaro because the floated values appear after conversion operations during export, but I couldn't find exactly where.

• CVAT engine/test_rest_api.py unit tests on import-export that use POST api/tasks/{id}/data (e.g. these ones) crash, because of the assertion that the frame filenames will stay the same on import, which is not the case. Solution for now: skip Market-1501 format altogether since it's the only format that has strict naming conventions.