Replace copied createIndex/loadRes/evaluate in references/*/coco_eval.py by calls to original functions + contextlib.redirect_stdout to suppress prints

🚀 The feature

Motivation for the copies is only removing prints. In Python 3 this can easily be achieved by using https://docs.python.org/3/library/contextlib.html?highlight=context#contextlib.redirect_stdout around calls to evaluate/loadRes

Motivation, pitch

Less code to maintain, less code for users to copy-paste/read/understand (since currently references code is invited to be simple scaffolding for users to copy and modify)

Alternatives

No response

Additional context

Also, import torch._six could be eliminated

cc @datumbox

[vadimkantorov]

So I think: https://github.com/facebookresearch/detr/blob/eb9f7e03ed8e2ed2cd55528989fe7df890bc3fc0/datasets/coco_eval.py#L51 : img_ids, eval_imgs = evaluate(coco_eval) could be replaced by coco_eval.evaluate(); eval_imgs = np.asarray(coco_eval.evalImgs).reshape(-1, len(coco_eval.params.areaRng), len(coco_eval.params.imgIds))

And then custom evaluate() could go.

Does it make sense @fmassa?

[vadimkantorov]

Maybe also simplify synchronize_between_processes, create_common_coco_eval and merge into a single

    def synchronize_between_processes(self):
        for iou_type, coco_eval in self.coco_eval.items():
            self.eval_imgs[iou_type] = np.concatenate(self.eval_imgs[iou_type], 2)

            all_img_ids = utils.all_gather(self.img_ids)
            all_eval_imgs = utils.all_gather(self.eval_imgs[iou_type])

            merged_img_ids = np.array([s for p in all_img_ids for s in p])
            merged_img_ids, idx = np.unique(merged_img_ids, return_index=True)
            merged_eval_imgs = np.concatenate(all_eval_imgs, 2)
            merged_eval_imgs = merged_eval_imgs[..., idx]

            coco_eval.evalImgs = list(merged_eval_imgs.flatten())
            coco_eval.params.imgIds = list(merged_img_ids)
            coco_eval._paramsEval = copy.deepcopy(coco_eval.params)