[refactor] Init

texteller/api/detection/preprocess.py

@@ -0,0 +1,161 @@
+import copy
+
+import cv2
+import numpy as np
+
+
+def decode_image(img_path):
+    if isinstance(img_path, str):
+        with open(img_path, "rb") as f:
+            im_read = f.read()
+        data = np.frombuffer(im_read, dtype="uint8")
+    else:
+        assert isinstance(img_path, np.ndarray)
+        data = img_path
+
+    im = cv2.imdecode(data, 1)  # BGR mode, but need RGB mode
+    im = cv2.cvtColor(im, cv2.COLOR_BGR2RGB)
+    img_info = {
+        "im_shape": np.array(im.shape[:2], dtype=np.float32),
+        "scale_factor": np.array([1.0, 1.0], dtype=np.float32),
+    }
+    return im, img_info
+
+
+class Resize(object):
+    """resize image by target_size and max_size
+    Args:
+        target_size (int): the target size of image
+        keep_ratio (bool): whether keep_ratio or not, default true
+        interp (int): method of resize
+    """
+
+    def __init__(self, target_size, keep_ratio=True, interp=cv2.INTER_LINEAR):
+        if isinstance(target_size, int):
+            target_size = [target_size, target_size]
+        self.target_size = target_size
+        self.keep_ratio = keep_ratio
+        self.interp = interp
+
+    def __call__(self, im, im_info):
+        """
+        Args:
+            im (np.ndarray): image (np.ndarray)
+            im_info (dict): info of image
+        Returns:
+            im (np.ndarray):  processed image (np.ndarray)
+            im_info (dict): info of processed image
+        """
+        assert len(self.target_size) == 2
+        assert self.target_size[0] > 0 and self.target_size[1] > 0
+        im_channel = im.shape[2]
+        im_scale_y, im_scale_x = self.generate_scale(im)
+        im = cv2.resize(im, None, None, fx=im_scale_x, fy=im_scale_y, interpolation=self.interp)
+        im_info["im_shape"] = np.array(im.shape[:2]).astype("float32")
+        im_info["scale_factor"] = np.array([im_scale_y, im_scale_x]).astype("float32")
+        return im, im_info
+
+    def generate_scale(self, im):
+        """
+        Args:
+            im (np.ndarray): image (np.ndarray)
+        Returns:
+            im_scale_x: the resize ratio of X
+            im_scale_y: the resize ratio of Y
+        """
+        origin_shape = im.shape[:2]
+        im_c = im.shape[2]
+        if self.keep_ratio:
+            im_size_min = np.min(origin_shape)
+            im_size_max = np.max(origin_shape)
+            target_size_min = np.min(self.target_size)
+            target_size_max = np.max(self.target_size)
+            im_scale = float(target_size_min) / float(im_size_min)
+            if np.round(im_scale * im_size_max) > target_size_max:
+                im_scale = float(target_size_max) / float(im_size_max)
+            im_scale_x = im_scale
+            im_scale_y = im_scale
+        else:
+            resize_h, resize_w = self.target_size
+            im_scale_y = resize_h / float(origin_shape[0])
+            im_scale_x = resize_w / float(origin_shape[1])
+        return im_scale_y, im_scale_x
+
+
+class NormalizeImage(object):
+    """normalize image
+    Args:
+        mean (list): im - mean
+        std (list): im / std
+        is_scale (bool): whether need im / 255
+        norm_type (str): type in ['mean_std', 'none']
+    """
+
+    def __init__(self, mean, std, is_scale=True, norm_type="mean_std"):
+        self.mean = mean
+        self.std = std
+        self.is_scale = is_scale
+        self.norm_type = norm_type
+
+    def __call__(self, im, im_info):
+        """
+        Args:
+            im (np.ndarray): image (np.ndarray)
+            im_info (dict): info of image
+        Returns:
+            im (np.ndarray):  processed image (np.ndarray)
+            im_info (dict): info of processed image
+        """
+        im = im.astype(np.float32, copy=False)
+        if self.is_scale:
+            scale = 1.0 / 255.0
+            im *= scale
+
+        if self.norm_type == "mean_std":
+            mean = np.array(self.mean)[np.newaxis, np.newaxis, :]
+            std = np.array(self.std)[np.newaxis, np.newaxis, :]
+            im -= mean
+            im /= std
+        return im, im_info
+
+
+class Permute(object):
+    """permute image
+    Args:
+        to_bgr (bool): whether convert RGB to BGR
+        channel_first (bool): whether convert HWC to CHW
+    """
+
+    def __init__(
+        self,
+    ):
+        super(Permute, self).__init__()
+
+    def __call__(self, im, im_info):
+        """
+        Args:
+            im (np.ndarray): image (np.ndarray)
+            im_info (dict): info of image
+        Returns:
+            im (np.ndarray):  processed image (np.ndarray)
+            im_info (dict): info of processed image
+        """
+        im = im.transpose((2, 0, 1)).copy()
+        return im, im_info
+
+
+class Compose:
+    def __init__(self, transforms):
+        self.transforms = []
+        for op_info in transforms:
+            new_op_info = op_info.copy()
+            op_type = new_op_info.pop("type")
+            self.transforms.append(eval(op_type)(**new_op_info))
+
+    def __call__(self, img_path):
+        img, im_info = decode_image(img_path)
+        for t in self.transforms:
+            img, im_info = t(img, im_info)
+        inputs = copy.deepcopy(im_info)
+        inputs["image"] = img
+        return inputs