OpenOCR/tools/utils/visual.py

import cv2
import random
import math
import numpy as np
from PIL import Image, ImageDraw, ImageFont

__all__ = ["draw_system", "draw_det"]


def draw_det(dt_boxes, img):
    for box in dt_boxes:
        box = np.array(box).astype(np.int32).reshape(-1, 2)
        cv2.polylines(img, [box], True, color=(255, 255, 0), thickness=2)
    return img


def draw_system(
        image,
        boxes,
        txts=None,
        scores=None,
        drop_score=0.5,
        font_path="./doc/fonts/simfang.ttf", ):
    h, w = image.height, image.width
    img_left = image.copy()
    img_right = np.ones((h, w, 3), dtype=np.uint8) * 255
    random.seed(0)

    draw_left = ImageDraw.Draw(img_left)
    if txts is None or len(txts) != len(boxes):
        txts = [None] * len(boxes)
    for idx, (box, txt) in enumerate(zip(boxes, txts)):
        if scores is not None and scores[idx] < drop_score:
            continue
        color = (random.randint(0, 255), random.randint(0, 255),
                 random.randint(0, 255))
        draw_left.polygon(box, fill=color)
        img_right_text = draw_box_txt_fine((w, h), box, txt, font_path)
        pts = np.array(box, np.int32).reshape((-1, 1, 2))
        cv2.polylines(img_right_text, [pts], True, color, 1)
        img_right = cv2.bitwise_and(img_right, img_right_text)
    img_left = Image.blend(image, img_left, 0.5)
    img_show = Image.new("RGB", (w * 2, h), (255, 255, 255))
    img_show.paste(img_left, (0, 0, w, h))
    img_show.paste(Image.fromarray(img_right), (w, 0, w * 2, h))
    return np.array(img_show)


def draw_box_txt_fine(img_size, box, txt, font_path="./doc/fonts/simfang.ttf"):
    box_height = int(
        math.sqrt((box[0][0] - box[3][0])**2 + (box[0][1] - box[3][1])**2))
    box_width = int(
        math.sqrt((box[0][0] - box[1][0])**2 + (box[0][1] - box[1][1])**2))

    if box_height > 2 * box_width and box_height > 30:
        img_text = Image.new("RGB", (box_height, box_width), (255, 255, 255))
        draw_text = ImageDraw.Draw(img_text)
        if txt:
            font = create_font(txt, (box_height, box_width), font_path)
            draw_text.text([0, 0], txt, fill=(0, 0, 0), font=font)
        img_text = img_text.transpose(Image.ROTATE_270)
    else:
        img_text = Image.new("RGB", (box_width, box_height), (255, 255, 255))
        draw_text = ImageDraw.Draw(img_text)
        if txt:
            font = create_font(txt, (box_width, box_height), font_path)
            draw_text.text([0, 0], txt, fill=(0, 0, 0), font=font)

    pts1 = np.float32(
        [[0, 0], [box_width, 0], [box_width, box_height], [0, box_height]])
    pts2 = np.array(box, dtype=np.float32)
    M = cv2.getPerspectiveTransform(pts1, pts2)

    img_text = np.array(img_text, dtype=np.uint8)
    img_right_text = cv2.warpPerspective(
        img_text,
        M,
        img_size,
        flags=cv2.INTER_NEAREST,
        borderMode=cv2.BORDER_CONSTANT,
        borderValue=(255, 255, 255), )
    return img_right_text


def create_font(txt, sz, font_path="./doc/fonts/simfang.ttf"):
    font_size = int(sz[1] * 0.99)
    font = ImageFont.truetype(font_path, font_size, encoding="utf-8")
    length = font.getlength(txt)
    if length > sz[0]:
        font_size = int(font_size * sz[0] / length)
        font = ImageFont.truetype(font_path, font_size, encoding="utf-8")
    return font


def str_count(s):
    """
    Count the number of Chinese characters,
    a single English character and a single number
    equal to half the length of Chinese characters.
    args:
        s(string): the input of string
    return(int):
        the number of Chinese characters
    """
    import string

    count_zh = count_pu = 0
    s_len = len(s)
    en_dg_count = 0
    for c in s:
        if c in string.ascii_letters or c.isdigit() or c.isspace():
            en_dg_count += 1
        elif c.isalpha():
            count_zh += 1
        else:
            count_pu += 1
    return s_len - math.ceil(en_dg_count / 2)