Invalid num_keypoints field value

[HarrisDePerceptron]

Firstly thanks for sharing the dataset.

While looking into the data in perticular the annotaions dictionary which is suppose to follow the coco format has invalid values for the field num_keypoints.

All columns values seems to indicate a constant 3 value. the coco format for keypoints indicate this field should be the sum of keypoints with visibility > 0 but seems not to be the case:

@Fang-Haoshu @HaoyiZhu