1#!/usr/bin/env python3
2# Copyright (c) 2021 Huawei Device Co., Ltd.
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7#     http://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14
15import cv2
16import sys
17import os
18from datetime import datetime
19
20DEBUG = False
21DEBUG = True
22TARGET_WIDTH = 128
23TARGET_HEIGHT = 64
24PIXEL_PER_BYTE = 8
25WIDTH_BYTES = int(TARGET_WIDTH/PIXEL_PER_BYTE)
26PIXEL_THRESHOLD = 128.0
27
28# 将多个灰度像素打包到一个整数中
29def pack_pixels(pixels, threshold):
30    value = 0
31    for gray in pixels:
32        bit = 1 if gray >= threshold else 0 # 二值化
33        value = (value << 1) + bit # 多个二值化像素值拼接为一个字节值
34    return value
35
36frameCount = 0
37def resize_and_binarize_image(frame, width, height, threshold):
38    data = []
39    # count = 0 # for debug
40    start = datetime.now()
41    frame = cv2.resize(frame, (width, height)) # 缩放
42    frame = cv2.cvtColor(frame, cv2.COLOR_RGB2GRAY) # 转为灰度图
43    _, binary = cv2.threshold(frame, threshold, 255, cv2.THRESH_BINARY) # 二值化
44
45    for r in range(height):
46        for b in range(int(width / PIXEL_PER_BYTE)):
47            colStart = b * PIXEL_PER_BYTE
48            pixels = frame[r, colStart: colStart + PIXEL_PER_BYTE]
49            byte = pack_pixels(pixels, threshold)
50            data.append(byte)
51    if DEBUG:
52        global frameCount
53        cv2.imwrite(os.path.join('debug', str(frameCount) + '.png'), frame)
54        cv2.imwrite(os.path.join('debug', str(frameCount) + '-bin.png'), binary)
55        frameCount += 1
56        end = datetime.now()
57        print('time cost:', end - start)
58    return bytes(data)
59
60def convert_frame_to_bytes(frame):
61    return resize_and_binarize_image(frame, TARGET_WIDTH, TARGET_HEIGHT, PIXEL_THRESHOLD)
62
63def main():
64    if len(sys.argv) < 3:
65        print("Usage: {} input outdir [width] [height] [threshod]".format(sys.argv[0]))
66        exit(-1)
67
68    imgPath = sys.argv[1]
69    outdir = sys.argv[2]
70    width = len(sys.argv) > 3 and int(sys.argv[3]) or TARGET_WIDTH
71    height = len(sys.argv) > 4 and int(sys.argv[4]) or TARGET_HEIGHT
72    threshold = len(sys.argv) > 5 and int(sys.argv[5]) or PIXEL_THRESHOLD
73    imgFile = os.path.split(imgPath)[-1]
74    imgBase = imgFile.split('.')[-2]
75    codeFile = os.path.join(outdir, imgBase + '.c')
76    if not os.path.exists(outdir):
77        os.mkdir(outdir)
78
79    frame = cv2.imread(imgPath) # 加载图片
80    bitmap = resize_and_binarize_image(frame, width, height, threshold) # 转为目标格式的数组
81
82    with open(codeFile, 'w+') as f: # 输出到.c文件
83        f.write('const unsigned char {}_size[] = {{ {}, {} }};\n'.format(imgBase, width, height))
84        f.write('const unsigned char {}[] = {{\n'.format(imgBase))
85        for i in range(len(bitmap)):
86            v = bitmap[i]
87            sep = '\n' if (i+1) % (TARGET_WIDTH/PIXEL_PER_BYTE) == 0 else ' '
88            f.write('0x%02X,%s' % (v, sep))
89        f.write('};\n')
90    print(imgFile, '=>', codeFile, 'done!')
91
92if __name__ == "__main__":
93    main()
94