datasets.py 文件源码

def _retrieve_sample(self, annotation):
        epsilon = 0.05
        high_val = 1 - epsilon
        low_val = 0 + epsilon
        coco_image = self._coco.loadImgs(annotation['image_id'])[0]
        image_path = os.path.join(self._config.data_dir['images'], coco_image['file_name'])
        image = utils.load_image(image_path)

        ann_mask = self._coco.annToMask(annotation)

        mask_categorical = np.full((ann_mask.shape[0], ann_mask.shape[1], self.num_classes()), low_val, dtype=np.float32)
        mask_categorical[:, :, 0] = high_val  # every pixel begins as background

        class_index = self._cid_to_id[annotation['category_id']]
        mask_categorical[ann_mask > 0, class_index] = high_val
        mask_categorical[ann_mask > 0, 0] = low_val  # remove background label from pixels of this (non-bg) category
        return image, mask_categorical