Python cv2.copyMakeBorder() Examples

def inpaint(self, missing_value=0):
        """
        Inpaint missing values in depth image.
        :param missing_value: Value to fill in teh depth image.
        """
        # cv2 inpainting doesn't handle the border properly
        # https://stackoverflow.com/questions/25974033/inpainting-depth-map-still-a-black-image-border
        self.img = cv2.copyMakeBorder(self.img, 1, 1, 1, 1, cv2.BORDER_DEFAULT)
        mask = (self.img == missing_value).astype(np.uint8)

        # Scale to keep as float, but has to be in bounds -1:1 to keep opencv happy.
        scale = np.abs(self.img).max()
        self.img = self.img.astype(np.float32) / scale  # Has to be float32, 64 not supported.
        self.img = cv2.inpaint(self.img, mask, 1, cv2.INPAINT_NS)

        # Back to original size and value range.
        self.img = self.img[1:-1, 1:-1]
        self.img = self.img * scale 

def __getitem__(self, index):
        datafiles = self.files[index]
        image = cv2.imread(datafiles["img"], cv2.IMREAD_COLOR)
        size = image.shape
        name = osp.splitext(osp.basename(datafiles["img"]))[0]
        image = np.asarray(image, np.float32)
        image -= self.mean
        
        img_h, img_w, _ = image.shape
        pad_h = max(self.crop_h - img_h, 0)
        pad_w = max(self.crop_w - img_w, 0)
        if pad_h > 0 or pad_w > 0:
            image = cv2.copyMakeBorder(image, 0, pad_h, 0, 
                pad_w, cv2.BORDER_CONSTANT, 
                value=(0.0, 0.0, 0.0))
        image = image.transpose((2, 0, 1))
        return image, name, size 

def __getitem__(self, index):
        datafiles = self.files[index]
        image = cv2.imread(datafiles["img"], cv2.IMREAD_COLOR)
        label = cv2.imread(datafiles["label"], cv2.IMREAD_GRAYSCALE)
        size = image.shape
        name = datafiles["name"]
        if self.scale:
            image, label = self.generate_scale_label(image, label)
        image = np.asarray(image, np.float32)
        image -= self.mean
        img_h, img_w = label.shape
        pad_h = max(self.crop_h - img_h, 0)
        pad_w = max(self.crop_w - img_w, 0)
        if pad_h > 0 or pad_w > 0:
            img_pad = cv2.copyMakeBorder(image, 0, pad_h, 0, 
                pad_w, cv2.BORDER_CONSTANT, 
                value=(0.0, 0.0, 0.0))
            label_pad = cv2.copyMakeBorder(label, 0, pad_h, 0, 
                pad_w, cv2.BORDER_CONSTANT,
                value=(self.ignore_label,))
        else:
            img_pad, label_pad = image, label

        img_h, img_w = label_pad.shape
        h_off = random.randint(0, img_h - self.crop_h)
        w_off = random.randint(0, img_w - self.crop_w)
        # roi = cv2.Rect(w_off, h_off, self.crop_w, self.crop_h);
        image = np.asarray(img_pad[h_off : h_off+self.crop_h, w_off : w_off+self.crop_w], np.float32)
        label = np.asarray(label_pad[h_off : h_off+self.crop_h, w_off : w_off+self.crop_w], np.float32)
        #image = image[:, :, ::-1]  # change to BGR
        image = image.transpose((2, 0, 1))
        if self.is_mirror:
            flip = np.random.choice(2) * 2 - 1
            image = image[:, :, ::flip]
            label = label[:, ::flip]

        return image.copy(), label.copy(), np.array(size), name 

def _pad_input_image(img, max_steps):
        """pad image to suitable shape"""

        logger.info(msg="_pad_input_image called")
        img_h, img_w, _ = img.shape

        img_pad_h = 0
        if img_h % max_steps > 0:
            img_pad_h = max_steps - img_h % max_steps

        img_pad_w = 0
        if img_w % max_steps > 0:
            img_pad_w = max_steps - img_w % max_steps

        padd_val = np.mean(img, axis=(0, 1)).astype(np.uint8)
        img = cv2.copyMakeBorder(img, 0, img_pad_h, 0, img_pad_w,
                                 cv2.BORDER_CONSTANT, value=padd_val.tolist())
        pad_params = [img_h, img_w, img_pad_h, img_pad_w]

        return img, pad_params 

def __getitem__(self, index):
        datafiles = self.files[index]
        image = cv2.imread(datafiles["img"], cv2.IMREAD_COLOR)
        size = image.shape
        name = osp.splitext(osp.basename(datafiles["img"]))[0]
        image = np.asarray(image, np.float32)
        image -= self.mean
        
        img_h, img_w, _ = image.shape
        pad_h = max(self.crop_h - img_h, 0)
        pad_w = max(self.crop_w - img_w, 0)
        if pad_h > 0 or pad_w > 0:
            image = cv2.copyMakeBorder(image, 0, pad_h, 0, 
                pad_w, cv2.BORDER_CONSTANT, 
                value=(0.0, 0.0, 0.0))
        image = image.transpose((2, 0, 1))
        return image, name, size 

def cut_patch(self, image: np.ndarray, slice_index, border_type=cv2.BORDER_CONSTANT, value=0):
        assert image.shape[0] == self.image_height
        assert image.shape[1] == self.image_width

        orig_shape_len = len(image.shape)
        image = cv2.copyMakeBorder(image, self.margin_top, self.margin_bottom, self.margin_left, self.margin_right, borderType=border_type, value=value)

        # This check recovers possible lack of last dummy dimension for single-channel images
        if len(image.shape) != orig_shape_len:
            image = np.expand_dims(image, axis=-1)

        x, y, tile_width, tile_height = self.crops[slice_index]

        tile = image[y:y + tile_height, x:x + tile_width].copy()
        assert tile.shape[0] == self.tile_size[0]
        assert tile.shape[1] == self.tile_size[1]
        return tile 

def __getitem__(self, index):
        datafiles = self.files[index]
        image = cv2.imread(datafiles["img"], cv2.IMREAD_COLOR)
        label = cv2.imread(datafiles["label"], cv2.IMREAD_GRAYSCALE)
        label = self.id2trainId(label)
        size = image.shape
        name = datafiles["name"]
        if self.scale:
            image, label = self.generate_scale_label(image, label)
        image = np.asarray(image, np.float32)
        image -= self.mean
        img_h, img_w = label.shape
        pad_h = max(self.crop_h - img_h, 0)
        pad_w = max(self.crop_w - img_w, 0)
        if pad_h > 0 or pad_w > 0:
            img_pad = cv2.copyMakeBorder(image, 0, pad_h, 0, 
                pad_w, cv2.BORDER_CONSTANT, 
                value=(0.0, 0.0, 0.0))
            label_pad = cv2.copyMakeBorder(label, 0, pad_h, 0, 
                pad_w, cv2.BORDER_CONSTANT,
                value=(self.ignore_label,))
        else:
            img_pad, label_pad = image, label

        img_h, img_w = label_pad.shape
        h_off = random.randint(0, img_h - self.crop_h)
        w_off = random.randint(0, img_w - self.crop_w)
        # roi = cv2.Rect(w_off, h_off, self.crop_w, self.crop_h);
        image = np.asarray(img_pad[h_off : h_off+self.crop_h, w_off : w_off+self.crop_w], np.float32)
        label = np.asarray(label_pad[h_off : h_off+self.crop_h, w_off : w_off+self.crop_w], np.float32)
        #image = image[:, :, ::-1]  # change to BGR
        image = image.transpose((2, 0, 1))
        if self.is_mirror:
            flip = np.random.choice(2) * 2 - 1
            image = image[:, :, ::flip]
            label = label[:, ::flip]

        return image.copy(), label.copy(), np.array(size), name 

def copyMakeBorder(src, top, bot, left, right, border_type=cv2.BORDER_CONSTANT, value=0):
    """Pad image border
    Wrapper for cv2.copyMakeBorder that uses mx.nd.NDArray

    Parameters
    ----------
    src : NDArray
        Image in (width, height, channels).
        Others are the same with cv2.copyMakeBorder

    Returns
    -------
    img : NDArray
        padded image
    """
    hdl = NDArrayHandle()
    check_call(_LIB.MXCVcopyMakeBorder(src.handle, ctypes.c_int(top), ctypes.c_int(bot),
                                       ctypes.c_int(left), ctypes.c_int(right),
                                       ctypes.c_int(border_type), ctypes.c_double(value),
                                       ctypes.byref(hdl)))
    return mx.nd.NDArray(hdl) 

def split(self, image, border_type=cv2.BORDER_CONSTANT, value=0):
        assert image.shape[0] == self.image_height
        assert image.shape[1] == self.image_width

        orig_shape_len = len(image.shape)
        image = cv2.copyMakeBorder(image, self.margin_top, self.margin_bottom, self.margin_left, self.margin_right, borderType=border_type, value=value)

        # This check recovers possible lack of last dummy dimension for single-channel images
        if len(image.shape) != orig_shape_len:
            image = np.expand_dims(image, axis=-1)

        tiles = []
        for x, y, tile_width, tile_height in self.crops:
            tile = image[y:y + tile_height, x:x + tile_width].copy()
            assert tile.shape[0] == self.tile_size[0]
            assert tile.shape[1] == self.tile_size[1]

            tiles.append(tile)

        return tiles 

def step(self, amt=1):
        image = self._capFrame()

        if self.crop:
            image = image[self._cropY + self.yoff:self._ih - self._cropY +
                          self.yoff, self._cropX + self.xoff:self._iw - self._cropX + self.xoff]
        else:
            t, b, l, r = self._pad
            image = cv2.copyMakeBorder(
                image, t, b, l, r, cv2.BORDER_CONSTANT, value=[0, 0, 0])

        resized = cv2.resize(image, (self.width, self.height),
                             interpolation=cv2.INTER_LINEAR)
        if self.mirror:
            resized = cv2.flip(resized, 1)

        for y in range(self.height):
            for x in range(self.width):
                self.layout.set(x, y, tuple(resized[y, x][0:3])) 

def __getitem__(self, index):
        datafiles = self.files[index]
        image = cv2.imread(datafiles["img"], cv2.IMREAD_COLOR)
        image = cv2.resize(image, None, fx=0.5, fy=0.5, interpolation=cv2.INTER_LINEAR)
        size = image.shape
        name = osp.splitext(osp.basename(datafiles["img"]))[0]
        image = np.asarray(image, np.float32)
        image = (image - image.min()) / (image.max() - image.min())
        
        img_h, img_w, _ = image.shape
        pad_h = max(self.crop_h - img_h, 0)
        pad_w = max(self.crop_w - img_w, 0)
        if pad_h > 0 or pad_w > 0:
            image = cv2.copyMakeBorder(image, 0, pad_h, 0, 
                pad_w, cv2.BORDER_CONSTANT, 
                value=(0.0, 0.0, 0.0))
        image = image.transpose((2, 0, 1))
        return image, np.array(size), name 

def _resize_image(img):
    dst_width = CFG.ARCH.INPUT_SIZE[0]
    dst_height = CFG.ARCH.INPUT_SIZE[1]
    h_old, w_old, _ = img.shape
    height = dst_height
    width = int(w_old * height / h_old)
    if width < dst_width:
        left_padding = int((dst_width - width)/2)
        right_padding = dst_width - width - left_padding
        resized_img = cv2.resize(img, (width, height), interpolation=cv2.INTER_CUBIC)
        resized_img = cv2.copyMakeBorder(resized_img, 0, 0, left_padding, right_padding,
            cv2.BORDER_CONSTANT, value=[255, 255, 255])
    else:
        resized_img = cv2.resize(img, (dst_width, height), interpolation=cv2.INTER_CUBIC)

    return resized_img 

def pad_width(img,
                  stride,
                  pad_value,
                  min_dims):
        h, w, _ = img.shape
        h = min(min_dims[0], h)
        min_dims[0] = math.ceil(min_dims[0] / float(stride)) * stride
        min_dims[1] = max(min_dims[1], w)
        min_dims[1] = math.ceil(min_dims[1] / float(stride)) * stride
        top = int(math.floor((min_dims[0] - h) / 2.0))
        left = int(math.floor((min_dims[1] - w) / 2.0))
        bottom = int(min_dims[0] - h - top)
        right = int(min_dims[1] - w - left)
        pad = [top, left, bottom, right]
        padded_img = cv2.copyMakeBorder(
            src=img,
            top=top,
            bottom=bottom,
            left=left,
            right=right,
            borderType=cv2.BORDER_CONSTANT,
            value=pad_value)
        return padded_img, pad

# --------------------------------------------------------------------------------------------------------------------- 

def pad_width(img,
                  stride,
                  pad_value,
                  min_dims):
        h, w, _ = img.shape
        h = min(min_dims[0], h)
        min_dims[0] = math.ceil(min_dims[0] / float(stride)) * stride
        min_dims[1] = max(min_dims[1], w)
        min_dims[1] = math.ceil(min_dims[1] / float(stride)) * stride
        top = int(math.floor((min_dims[0] - h) / 2.0))
        left = int(math.floor((min_dims[1] - w) / 2.0))
        bottom = int(min_dims[0] - h - top)
        right = int(min_dims[1] - w - left)
        pad = [top, left, bottom, right]
        padded_img = cv2.copyMakeBorder(
            src=img,
            top=top,
            bottom=bottom,
            left=left,
            right=right,
            borderType=cv2.BORDER_CONSTANT,
            value=pad_value)
        return padded_img, pad

# --------------------------------------------------------------------------------------------------------------------- 

def pad_width(img,
                  stride,
                  pad_value,
                  min_dims):
        h, w, _ = img.shape
        h = min(min_dims[0], h)
        min_dims[0] = math.ceil(min_dims[0] / float(stride)) * stride
        min_dims[1] = max(min_dims[1], w)
        min_dims[1] = math.ceil(min_dims[1] / float(stride)) * stride
        top = int(math.floor((min_dims[0] - h) / 2.0))
        left = int(math.floor((min_dims[1] - w) / 2.0))
        bottom = int(min_dims[0] - h - top)
        right = int(min_dims[1] - w - left)
        pad = [top, left, bottom, right]
        padded_img = cv2.copyMakeBorder(
            src=img,
            top=top,
            bottom=bottom,
            left=left,
            right=right,
            borderType=cv2.BORDER_CONSTANT,
            value=pad_value)
        return padded_img, pad

# --------------------------------------------------------------------------------------------------------------------- 

def pad_width(img,
                  stride,
                  pad_value,
                  min_dims):
        h, w, _ = img.shape
        h = min(min_dims[0], h)
        min_dims[0] = math.ceil(min_dims[0] / float(stride)) * stride
        min_dims[1] = max(min_dims[1], w)
        min_dims[1] = math.ceil(min_dims[1] / float(stride)) * stride
        top = int(math.floor((min_dims[0] - h) / 2.0))
        left = int(math.floor((min_dims[1] - w) / 2.0))
        bottom = int(min_dims[0] - h - top)
        right = int(min_dims[1] - w - left)
        pad = [top, left, bottom, right]
        padded_img = cv2.copyMakeBorder(
            src=img,
            top=top,
            bottom=bottom,
            left=left,
            right=right,
            borderType=cv2.BORDER_CONSTANT,
            value=pad_value)
        return padded_img, pad

# --------------------------------------------------------------------------------------------------------------------- 

def __apply_template_matching(angle, template, image):
    # Rotate the template
    template_rotated = __rotate_image_size_corrected(template, angle)

    # Apply template matching
    image_templated = cv2.matchTemplate(image, template_rotated, cv2.TM_CCOEFF_NORMED)

    # Correct template matching image size difference
    template_rotated_height, template_rotated_width = template_rotated.shape
    template_half_height = template_rotated_height // 2
    template_half_width = template_rotated_width // 2

    image_templated_inrange_size_corrected = cv2.copyMakeBorder(image_templated, template_half_height, template_half_height, template_half_width, template_half_width, cv2.BORDER_CONSTANT, value=0)

    # Calculate maximum match coefficient
    max_match = numpy.max(image_templated_inrange_size_corrected)

    return (max_match, angle, template_rotated, image_templated_inrange_size_corrected) 

def __getitem__(self, index):
        datafiles = self.files[index]
        image = cv2.imread(datafiles["img"], cv2.IMREAD_COLOR)
        size = image.shape
        name = osp.splitext(osp.basename(datafiles["img"]))[0]
        image = np.asarray(image, np.float32)
        image -= self.mean
        
        img_h, img_w, _ = image.shape
        pad_h = max(self.crop_h - img_h, 0)
        pad_w = max(self.crop_w - img_w, 0)
        if pad_h > 0 or pad_w > 0:
            image = cv2.copyMakeBorder(image, 0, pad_h, 0, 
                pad_w, cv2.BORDER_CONSTANT, 
                value=(0.0, 0.0, 0.0))
        image = image.transpose((2, 0, 1))
        return image, np.array(size), name 

def load_label(self, idx):
        """
        Load label image as 1 x height x width integer array of label indices.
        The leading singleton dimension is required by the loss.
        """
        im = Image.open(self.data_root + self.label_lst[idx])
        label = np.array(im) / 255#cv2.imread(self.data_root + self.label_lst[idx], 0) / 255
        #if self.scales != None:
        #    label = cv2.resize(label, None, None, fx=self.scales[self.scale_ind], fy=self.scales[self.scale_ind], \
        #            interpolation=cv2.INTER_NEAREST)
        #height, width = label.shape[:2]
        #h_off = self.crop_size - height
        #w_off = self.crop_size - width
        #label = cv2.copyMakeBorder(label, 0, max(0, h_off), 0, max(0, w_off), cv2.BORDER_CONSTANT, value=[-1,])
        #label = label[self.h_off:self.h_off+self.height, self.w_off:self.w_off+self.width]
        label = label[np.newaxis, ...]
        if self.flip == 1:
            label = label[:,:,::-1]
        return label 

def load_region(self, idx):
        """
        Load label image as 1 x height x width integer array of label indices.
        The leading singleton dimension is required by the loss.
        """
        im = Image.open(self.data_root + self.region_lst[idx])
        region = np.array(im, dtype=np.float32) / 15.0
        #print np.unique(region)
        #if self.scales != None:
        #    label = cv2.resize(label, None, None, fx=self.scales[self.scale_ind], fy=self.scales[self.scale_ind], \
        #            interpolation=cv2.INTER_NEAREST)
        #height, width = label.shape[:2]
        #h_off = self.crop_size - height
        #w_off = self.crop_size - width
        #label = cv2.copyMakeBorder(label, 0, max(0, h_off), 0, max(0, w_off), cv2.BORDER_CONSTANT, value=[-1,])
        region = region[np.newaxis, ...]
        if self.flip == 1:
            region = region[:,:,::-1]
        return region 

def __getitem__(self, index):
        datafiles = self.files[index]
        image = cv2.imread(datafiles["img"], cv2.IMREAD_COLOR)
        size = image.shape
        name = osp.splitext(osp.basename(datafiles["img"]))[0]
        image = np.asarray(image, np.float32)
        image -= self.mean
        
        img_h, img_w, _ = image.shape
        pad_h = max(self.crop_h - img_h, 0)
        pad_w = max(self.crop_w - img_w, 0)
        if pad_h > 0 or pad_w > 0:
            image = cv2.copyMakeBorder(image, 0, pad_h, 0, 
                pad_w, cv2.BORDER_CONSTANT, 
                value=(0.0, 0.0, 0.0))
        image = image.transpose((2, 0, 1))
        return image, name, size 

def PreprocessImage(name, args):
    """Preprocess according to the original author's code."""

    image = cv2.imread(name, 1).astype(np.float32) - args.mean

    if args.resize_dims is not None:
        image = cv2.resize(image, dsize = (args.resize_dims[0], args.resize_dims[1]))

    im_height = image.shape[0]
    im_width = image.shape[1]

    label_margin = 186
    input_image = cv2.copyMakeBorder(image, label_margin, label_margin,
                                     label_margin, label_margin, cv2.BORDER_REFLECT_101)
    input_size = [args.pad_size[1], args.pad_size[0]] # Order is H x W
    margin = [0, input_size[0] - input_image.shape[0],
              0, input_size[1] - input_image.shape[1]]

    input_image = cv2.copyMakeBorder(input_image, margin[0], margin[1], margin[2],
                                     margin[3], cv2.BORDER_REFLECT_101)

    input_image = input_image.transpose([2,0,1]) # To make it C x H x W
    return input_image, im_height, im_width, image 

def label_images(images, labels):
    font = cv.FONT_HERSHEY_SIMPLEX
    new_imgs = []
    for i, img in enumerate(images):
        new_img = ((img.copy() + 1.) * 127.5).astype(np.uint8)
        if new_img.shape[-1] == 3:
            new_img = new_img[..., ::-1]
            new_img = cv.resize(new_img, (100, 100), interpolation=cv.INTER_LINEAR)
            new_img = cv.putText(new_img, str(labels[i]), (10, 30), font, 1, (255, 255, 255), 2, cv.LINE_AA)
            new_img = cv.copyMakeBorder(new_img, top=2, bottom=2, left=2, right=2, borderType=cv.BORDER_CONSTANT,
                                        value=(255, 255, 255))
        else:
            new_img = np.squeeze(new_img)
            new_img = cv.resize(new_img, (100, 100), interpolation=cv.INTER_LINEAR)
            new_img = cv.putText(new_img, str(labels[i]), (10, 30), font, 1, (255), 2, cv.LINE_AA)
            new_img = new_img[..., None]

        new_img = (new_img / 127.5 - 1.0).astype(np.float32)
        new_imgs.append(new_img[..., ::-1])
    return np.stack(new_imgs, axis=0) 

def step(self, amt=1):
        ret, frame = self._vid.read()

        image = cv2.cvtColor(frame, cv2.COLOR_RGB2BGRA)

        if self.crop:
            image = image[self._cropY + self.yoff:self._ih - self._cropY +
                          self.yoff, self._cropX + self.xoff:self._iw - self._cropX + self.xoff]
        else:
            t, b, l, r = self._pad
            image = cv2.copyMakeBorder(
                image, t, b, l, r, cv2.BORDER_CONSTANT, value=[0, 0, 0])

        resized = cv2.resize(image, (self.width, self.height),
                             interpolation=cv2.INTER_CUBIC)
        if self.mirror:
            resized = cv2.flip(resized, 1)

        for y in range(self.height):
            for x in range(self.width):
                self.layout.set(x, y, tuple(resized[y, x][0:3]))

        if not isinstance(self.videoSource, int):
            self._frameCount += 1
            if self._frameCount >= self._frameTotal:
                self._vid.set(1, 0)  # CV_CAP_PROP_POS_FRAMES
                self._frameCount = 0
                self.animComplete = True 

def __getitem__(self, index):
        datafiles = self.files[index]
        image = cv2.imread(datafiles["img"], cv2.IMREAD_COLOR)
        label = cv2.imread(datafiles["label"], cv2.IMREAD_GRAYSCALE)
        size = image.shape
        name = datafiles["name"]
        if self.scale:
            image, label = self.generate_scale_label(image, label)
        image = np.asarray(image, np.float32)
        image -= self.mean
        img_h, img_w = label.shape
        pad_h = max(self.crop_h - img_h, 0)
        pad_w = max(self.crop_w - img_w, 0)
        if pad_h > 0 or pad_w > 0:
            img_pad = cv2.copyMakeBorder(image, 0, pad_h, 0, 
                pad_w, cv2.BORDER_CONSTANT, 
                value=(0.0, 0.0, 0.0))
            label_pad = cv2.copyMakeBorder(label, 0, pad_h, 0, 
                pad_w, cv2.BORDER_CONSTANT,
                value=(self.ignore_label,))
        else:
            img_pad, label_pad = image, label

        img_h, img_w = label_pad.shape
        h_off = random.randint(0, img_h - self.crop_h)
        w_off = random.randint(0, img_w - self.crop_w)
        # roi = cv2.Rect(w_off, h_off, self.crop_w, self.crop_h);
        image = np.asarray(img_pad[h_off : h_off+self.crop_h, w_off : w_off+self.crop_w], np.float32)
        label = np.asarray(label_pad[h_off : h_off+self.crop_h, w_off : w_off+self.crop_w], np.float32)
        #image = image[:, :, ::-1]  # change to BGR
        image = image.transpose((2, 0, 1))
        if self.is_mirror:
            flip = np.random.choice(2) * 2 - 1
            image = image[:, :, ::flip]
            label = label[:, ::flip]

        return image.copy(), label.copy(), np.array(size), name 

def scale_and_centre(img, size, margin=0, background=0):
	"""Scales and centres an image onto a new background square."""
	h, w = img.shape[:2]

	def centre_pad(length):
		"""Handles centering for a given length that may be odd or even."""
		if length % 2 == 0:
			side1 = int((size - length) / 2)
			side2 = side1
		else:
			side1 = int((size - length) / 2)
			side2 = side1 + 1
		return side1, side2

	def scale(r, x):
		return int(r * x)

	if h > w:
		t_pad = int(margin / 2)
		b_pad = t_pad
		ratio = (size - margin) / h
		w, h = scale(ratio, w), scale(ratio, h)
		l_pad, r_pad = centre_pad(w)
	else:
		l_pad = int(margin / 2)
		r_pad = l_pad
		ratio = (size - margin) / w
		w, h = scale(ratio, w), scale(ratio, h)
		t_pad, b_pad = centre_pad(h)

	img = cv2.resize(img, (w, h))
	img = cv2.copyMakeBorder(img, t_pad, b_pad, l_pad, r_pad, cv2.BORDER_CONSTANT, None, background)
	return cv2.resize(img, (size, size)) 

def show_digits(digits, colour=255):
    """Shows list of 81 extracted digits in a grid format"""
    rows = []
    with_border = [cv2.copyMakeBorder(img.copy(), 1, 1, 1, 1, cv2.BORDER_CONSTANT, None, colour) for img in digits]
    for i in range(9):
        row = np.concatenate(with_border[i * 9:((i + 1) * 9)], axis=1)
        rows.append(row)
    img = show_image(np.concatenate(rows))
    return img 

def __getitem__(self, index):
        datafiles = self.files[index]
        image = cv2.imread(datafiles["img"], cv2.IMREAD_COLOR)
        label = cv2.imread(datafiles["label"], cv2.IMREAD_GRAYSCALE)
        label = self.id2trainId(label)
        size = image.shape
        name = datafiles["name"]
        if self.scale:
            image, label = self.generate_scale_label(image, label)
        image = np.asarray(image, np.float32)
        image -= self.mean
        img_h, img_w = label.shape
        pad_h = max(self.crop_h - img_h, 0)
        pad_w = max(self.crop_w - img_w, 0)
        if pad_h > 0 or pad_w > 0:
            img_pad = cv2.copyMakeBorder(image, 0, pad_h, 0, 
                pad_w, cv2.BORDER_CONSTANT, 
                value=(0.0, 0.0, 0.0))
            label_pad = cv2.copyMakeBorder(label, 0, pad_h, 0, 
                pad_w, cv2.BORDER_CONSTANT,
                value=(self.ignore_label,))
        else:
            img_pad, label_pad = image, label

        img_h, img_w = label_pad.shape
        h_off = random.randint(0, img_h - self.crop_h)
        w_off = random.randint(0, img_w - self.crop_w)
        # roi = cv2.Rect(w_off, h_off, self.crop_w, self.crop_h);
        image = np.asarray(img_pad[h_off : h_off+self.crop_h, w_off : w_off+self.crop_w], np.float32)
        label = np.asarray(label_pad[h_off : h_off+self.crop_h, w_off : w_off+self.crop_w], np.float32)
        #image = image[:, :, ::-1]  # change to BGR
        image = image.transpose((2, 0, 1))
        if self.is_mirror:
            flip = np.random.choice(2) * 2 - 1
            image = image[:, :, ::flip]
            label = label[:, ::flip]

        return image.copy(), label.copy(), np.array(size), name 

def pad(img, offeset, value=0):
    h1, w1, h2, w2 = offeset
    img = cv2.copyMakeBorder(
        img, h1, h2, w1, w2, cv2.BORDER_CONSTANT, value=value)
    return img 

def letterbox(img, height=416, color=(127.5, 127.5, 127.5)):
    # Resize a rectangular image to a padded square
    shape = img.shape[:2]  # shape = [height, width]
    ratio = float(height) / max(shape)  # ratio  = old / new
    new_shape = (round(shape[1] * ratio), round(shape[0] * ratio))
    dw = (height - new_shape[0]) / 2  # width padding
    dh = (height - new_shape[1]) / 2  # height padding
    top, bottom = round(dh - 0.1), round(dh + 0.1)
    left, right = round(dw - 0.1), round(dw + 0.1)
    img = cv2.resize(img, new_shape, interpolation=cv2.INTER_AREA)  # resized, no border
    img = cv2.copyMakeBorder(img, top, bottom, left, right, cv2.BORDER_CONSTANT, value=color)  # padded square
    return img, ratio, dw, dh