init

backend/ppocr/data/imaug/random_crop_data.py

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+# copyright (c) 2020 PaddlePaddle Authors. All Rights Reserve.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""
+This code is refer from:
+https://github.com/WenmuZhou/DBNet.pytorch/blob/master/data_loader/modules/random_crop_data.py
+"""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+from __future__ import unicode_literals
+
+import numpy as np
+import cv2
+import random
+
+
+def is_poly_in_rect(poly, x, y, w, h):
+    poly = np.array(poly)
+    if poly[:, 0].min() < x or poly[:, 0].max() > x + w:
+        return False
+    if poly[:, 1].min() < y or poly[:, 1].max() > y + h:
+        return False
+    return True
+
+
+def is_poly_outside_rect(poly, x, y, w, h):
+    poly = np.array(poly)
+    if poly[:, 0].max() < x or poly[:, 0].min() > x + w:
+        return True
+    if poly[:, 1].max() < y or poly[:, 1].min() > y + h:
+        return True
+    return False
+
+
+def split_regions(axis):
+    regions = []
+    min_axis = 0
+    for i in range(1, axis.shape[0]):
+        if axis[i] != axis[i - 1] + 1:
+            region = axis[min_axis:i]
+            min_axis = i
+            regions.append(region)
+    return regions
+
+
+def random_select(axis, max_size):
+    xx = np.random.choice(axis, size=2)
+    xmin = np.min(xx)
+    xmax = np.max(xx)
+    xmin = np.clip(xmin, 0, max_size - 1)
+    xmax = np.clip(xmax, 0, max_size - 1)
+    return xmin, xmax
+
+
+def region_wise_random_select(regions, max_size):
+    selected_index = list(np.random.choice(len(regions), 2))
+    selected_values = []
+    for index in selected_index:
+        axis = regions[index]
+        xx = int(np.random.choice(axis, size=1))
+        selected_values.append(xx)
+    xmin = min(selected_values)
+    xmax = max(selected_values)
+    return xmin, xmax
+
+
+def crop_area(im, text_polys, min_crop_side_ratio, max_tries):
+    h, w, _ = im.shape
+    h_array = np.zeros(h, dtype=np.int32)
+    w_array = np.zeros(w, dtype=np.int32)
+    for points in text_polys:
+        points = np.round(points, decimals=0).astype(np.int32)
+        minx = np.min(points[:, 0])
+        maxx = np.max(points[:, 0])
+        w_array[minx:maxx] = 1
+        miny = np.min(points[:, 1])
+        maxy = np.max(points[:, 1])
+        h_array[miny:maxy] = 1
+    # ensure the cropped area not across a text
+    h_axis = np.where(h_array == 0)[0]
+    w_axis = np.where(w_array == 0)[0]
+
+    if len(h_axis) == 0 or len(w_axis) == 0:
+        return 0, 0, w, h
+
+    h_regions = split_regions(h_axis)
+    w_regions = split_regions(w_axis)
+
+    for i in range(max_tries):
+        if len(w_regions) > 1:
+            xmin, xmax = region_wise_random_select(w_regions, w)
+        else:
+            xmin, xmax = random_select(w_axis, w)
+        if len(h_regions) > 1:
+            ymin, ymax = region_wise_random_select(h_regions, h)
+        else:
+            ymin, ymax = random_select(h_axis, h)
+
+        if xmax - xmin < min_crop_side_ratio * w or ymax - ymin < min_crop_side_ratio * h:
+            # area too small
+            continue
+        num_poly_in_rect = 0
+        for poly in text_polys:
+            if not is_poly_outside_rect(poly, xmin, ymin, xmax - xmin,
+                                        ymax - ymin):
+                num_poly_in_rect += 1
+                break
+
+        if num_poly_in_rect > 0:
+            return xmin, ymin, xmax - xmin, ymax - ymin
+
+    return 0, 0, w, h
+
+
+class EastRandomCropData(object):
+    def __init__(self,
+                 size=(640, 640),
+                 max_tries=10,
+                 min_crop_side_ratio=0.1,
+                 keep_ratio=True,
+                 **kwargs):
+        self.size = size
+        self.max_tries = max_tries
+        self.min_crop_side_ratio = min_crop_side_ratio
+        self.keep_ratio = keep_ratio
+
+    def __call__(self, data):
+        img = data['image']
+        text_polys = data['polys']
+        ignore_tags = data['ignore_tags']
+        texts = data['texts']
+        all_care_polys = [
+            text_polys[i] for i, tag in enumerate(ignore_tags) if not tag
+        ]
+        # 计算crop区域
+        crop_x, crop_y, crop_w, crop_h = crop_area(
+            img, all_care_polys, self.min_crop_side_ratio, self.max_tries)
+        # crop 图片 保持比例填充
+        scale_w = self.size[0] / crop_w
+        scale_h = self.size[1] / crop_h
+        scale = min(scale_w, scale_h)
+        h = int(crop_h * scale)
+        w = int(crop_w * scale)
+        if self.keep_ratio:
+            padimg = np.zeros((self.size[1], self.size[0], img.shape[2]),
+                              img.dtype)
+            padimg[:h, :w] = cv2.resize(
+                img[crop_y:crop_y + crop_h, crop_x:crop_x + crop_w], (w, h))
+            img = padimg
+        else:
+            img = cv2.resize(
+                img[crop_y:crop_y + crop_h, crop_x:crop_x + crop_w],
+                tuple(self.size))
+        # crop 文本框
+        text_polys_crop = []
+        ignore_tags_crop = []
+        texts_crop = []
+        for poly, text, tag in zip(text_polys, texts, ignore_tags):
+            poly = ((poly - (crop_x, crop_y)) * scale).tolist()
+            if not is_poly_outside_rect(poly, 0, 0, w, h):
+                text_polys_crop.append(poly)
+                ignore_tags_crop.append(tag)
+                texts_crop.append(text)
+        data['image'] = img
+        data['polys'] = np.array(text_polys_crop)
+        data['ignore_tags'] = ignore_tags_crop
+        data['texts'] = texts_crop
+        return data
+
+
+class RandomCropImgMask(object):
+    def __init__(self, size, main_key, crop_keys, p=3 / 8, **kwargs):
+        self.size = size
+        self.main_key = main_key
+        self.crop_keys = crop_keys
+        self.p = p
+
+    def __call__(self, data):
+        image = data['image']
+
+        h, w = image.shape[0:2]
+        th, tw = self.size
+        if w == tw and h == th:
+            return data
+
+        mask = data[self.main_key]
+        if np.max(mask) > 0 and random.random() > self.p:
+            # make sure to crop the text region
+            tl = np.min(np.where(mask > 0), axis=1) - (th, tw)
+            tl[tl < 0] = 0
+            br = np.max(np.where(mask > 0), axis=1) - (th, tw)
+            br[br < 0] = 0
+
+            br[0] = min(br[0], h - th)
+            br[1] = min(br[1], w - tw)
+
+            i = random.randint(tl[0], br[0]) if tl[0] < br[0] else 0
+            j = random.randint(tl[1], br[1]) if tl[1] < br[1] else 0
+        else:
+            i = random.randint(0, h - th) if h - th > 0 else 0
+            j = random.randint(0, w - tw) if w - tw > 0 else 0
+
+        # return i, j, th, tw
+        for k in data:
+            if k in self.crop_keys:
+                if len(data[k].shape) == 3:
+                    if np.argmin(data[k].shape) == 0:
+                        img = data[k][:, i:i + th, j:j + tw]
+                        if img.shape[1] != img.shape[2]:
+                            a = 1
+                    elif np.argmin(data[k].shape) == 2:
+                        img = data[k][i:i + th, j:j + tw, :]
+                        if img.shape[1] != img.shape[0]:
+                            a = 1
+                    else:
+                        img = data[k]
+                else:
+                    img = data[k][i:i + th, j:j + tw]
+                    if img.shape[0] != img.shape[1]:
+                        a = 1
+                data[k] = img
+        return data