(target, num_level_grids)
return level_targets
Convert targets by image to targets by feature level.

    [target_img0, target_img1] -> [target_level0, target_level1, ...]
Convert targets by image to targets by feature level.
Convert targets by image to targets by feature level .
def images_to_levels(target, num_level_grids):
    """Convert targets by image to targets by feature level.

    [target_img0, target_img1] -> [target_level0, target_level1, ...]
    """
    target = torch.stack(target, 0)
    level_targets = []
    start = 0
    for n in num_level_grids:
        end = start + n
        level_targets.append(target[:, start:end].squeeze(0))
        start = end
    return level_targets
def images_to_levels ( target , num_level_grids ) : target = torch . stack ( target , 0 ) level_targets = [ ] start = 0 for n in num_level_grids : end = start + n level_targets . append ( target [ : , start : end ] . squeeze ( 0 ) ) start = end return level_targets