page_dewarp.py 文件源码

def remap_image(name, img, small, page_dims, params):

    height = 0.5 * page_dims[1] * OUTPUT_ZOOM * img.shape[0]
    height = round_nearest_multiple(height, REMAP_DECIMATE)

    width = round_nearest_multiple(height * page_dims[0] / page_dims[1],
                                   REMAP_DECIMATE)

    print '  output will be {}x{}'.format(width, height)

    height_small = height / REMAP_DECIMATE
    width_small = width / REMAP_DECIMATE

    page_x_range = np.linspace(0, page_dims[0], width_small)
    page_y_range = np.linspace(0, page_dims[1], height_small)

    page_x_coords, page_y_coords = np.meshgrid(page_x_range, page_y_range)

    page_xy_coords = np.hstack((page_x_coords.flatten().reshape((-1, 1)),
                                page_y_coords.flatten().reshape((-1, 1))))

    page_xy_coords = page_xy_coords.astype(np.float32)

    image_points = project_xy(page_xy_coords, params)
    image_points = norm2pix(img.shape, image_points, False)

    image_x_coords = image_points[:, 0, 0].reshape(page_x_coords.shape)
    image_y_coords = image_points[:, 0, 1].reshape(page_y_coords.shape)

    image_x_coords = cv2.resize(image_x_coords, (width, height),
                                interpolation=cv2.INTER_CUBIC)

    image_y_coords = cv2.resize(image_y_coords, (width, height),
                                interpolation=cv2.INTER_CUBIC)

    img_gray = cv2.cvtColor(img, cv2.COLOR_RGB2GRAY)

    remapped = cv2.remap(img_gray, image_x_coords, image_y_coords,
                         cv2.INTER_CUBIC,
                         None, cv2.BORDER_REPLICATE)

    thresh = cv2.adaptiveThreshold(remapped, 255, cv2.ADAPTIVE_THRESH_MEAN_C,
                                   cv2.THRESH_BINARY, ADAPTIVE_WINSZ, 25)

    pil_image = Image.fromarray(thresh)
    pil_image = pil_image.convert('1')

    threshfile = name + '_thresh.png'
    pil_image.save(threshfile, dpi=(OUTPUT_DPI, OUTPUT_DPI))

    if DEBUG_LEVEL >= 1:
        height = small.shape[0]
        width = int(round(height * float(thresh.shape[1])/thresh.shape[0]))
        display = cv2.resize(thresh, (width, height),
                             interpolation=cv2.INTER_AREA)
        debug_show(name, 6, 'output', display)

    return threshfile