Wrong coordinate conversion from Wildtrack to COCO

Hi Kostadinov,

The conversion from Wildtrack bbox coordinates to coco in wildtrack2mvcoco.py should actually be

        x = xmin
        y = ymin
        w = xmax - xmin
        h = ymax - ymin

instead of

        x = (xmax + xmin) / 2
        y = (ymax + ymin) / 2
        w = xmax - xmin
        h = ymax - ymin

I validated this claim visually with the following code snippet:

    from pycocotools.coco import COCO
    import numpy as np
    import skimage.io as io
    from matplotlib import pyplot as plt

    def check_coco_from_wildtrack(coco_dir='data/WILDTRACK/C1/train', annotation_file='data/WILDTRACK/C1/annotations/train.json', img_id=None):
        """
        Visualize generated COCO data. Only used for debugging.
        """
        if os.path.isdir("debug_images") is False:
            os.makedirs("debug_images")

        coco = COCO(annotation_file)
        cat_ids = coco.getCatIds(catNms=['person'])
        if img_id == None:
            img_ids = coco.getImgIds(catIds=cat_ids)

        for _ in range(20):
            #_ = 4
            #index = np.random.randint(0, len(img_ids))
            img_id = img_ids[_]
            img = coco.loadImgs(img_id)[0]

            i = io.imread(os.path.join(coco_dir, img['file_name']))

            plt.imshow(i)
            plt.axis('off')
            ann_ids = coco.getAnnIds(imgIds=img['id'], catIds=cat_ids, iscrowd=None)
            anns = coco.loadAnns(ann_ids)
            coco.showAnns(anns, draw_bbox=True)
            plt.savefig(f'debug_images/debug_{img["file_name"]}')
            # clear figures/bboxes for next picture
            plt.clf()

Best Regards Tobias

KostadinovShalon / MVViT

Wrong coordinate conversion from Wildtrack to COCO #2