开头吐槽:

垃圾Swift, 本来低版本系统直接编译成功, 结果到了高版本的系统报Swift版本低, 故有这篇文章. 虽然Swift是大势所趋, 但是吹Swift省省吧, 多余的时间用来享受不香吗, 折腾不成熟的东西, 脑袋大.

还有本来我调试arm64已成功, 最终兼容模拟器的时候又去编译x86_ 64, 引出问题4/5, 蛋疼.

😄😄😄想要 opencv2.framework 的直接看最后, 别浪费时间

先说环境:

macos Monterey 12.6.3 / M1 MacbookAir / Xcode14.2

opencv: 4.6.0

opencv_contrib: 4.6.0

下载opencv_ contrib后把里面的wechat _qrcode目前拷贝到/opencv-4.6.0/modules/wechat_qrcode

编译及问题

cd到你的opencv-4.6.0目录, 直接使用默认的python编译(python3):

python platforms/ios/build_framework.py ios
得到如下错误:
-- Configuring incomplete, errors occurred!
See also "/Users/ ****** * ***/Desktop/opencv-4.6.0/ios/build/build-arm64-iphoneos/CMakeFiles/CMakeOutput.log".***
See also "/Users/ ****** * ***/Desktop/opencv-4.6.0/ios/build/build-arm64-iphoneos/CMakeFiles/CMakeError.log".***
CMakeErrorLog
出现此问题:
Undefined symbols for architecture arm64:
  "_*iconv", referenced from:*
      _*main in src.o*
  "_*iconv_close", referenced from:*
      _*main in src.o*
  "_*iconv_open", referenced from:*
      _*main in src.o*
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
解决方案: 安装libiconv
xu@VIVO-S3 opencv-4.6.0 % brew install libiconv
重新编译得到错误
In file included from /Users/ ****** * ***/Desktop/opencv-4.6.0/3rdparty/libjpeg-turbo/src/jdphuff.c:26:***
******/Users/ ****** * ***/Desktop/opencv-4.6.0/3rdparty/libjpeg-turbo/src/jdhuff.h:77:19:* **** ***********error:* ****
****invalid token at start of a preprocessor expression****
if SIZEOF_SIZE_T == 8 || defined(_*WIN64)*
** **^** **
1 error generated.
解决方案: 
降低cmake版本, 安装 3.24.0
https://cmake.org/files/  下载对应的dmg包. 然后拖到/Applications目录, 然后安装命令行: 
sudo "/Applications/CMake.app/Contents/bin/cmake-gui" --install
⚠️⚠️⚠️此处多说一句, Xcode和cmake有个对应关系, 两者版本不一致, 编译各种问题. 大多数问题在编译x86_64的情况下出现, 自己善于查看CMakeError.log和CMakeOutput.log, 有时日志最后显示BUILD SUCCESS, 记得往上面翻*** BUILD FAILED
重新编译得到错误
  CMake Error at CMakeLists.txt:113 (enable_language):
  No CMAKE_CXX_COMPILER could be found.
  CMake Error at CMakeLists.txt:113 (enable_language):
  No CMAKE_C_COMPILER could be found.
解决方案:
删掉缓存目录, 之前编译生成的ios目录, 你的opencv-4.6.0目录下面的ios目录
CMake Error at CMakeLists.txt:11 (message):
  FATAL: In-source builds are not allowed.
         You should create a separate directory for build files.
解决方案:
不熟悉C++和cmake, 所以直接直接删掉opencv-4.6.0, 重新弄一个新的再次cd进去编译
github issue里面提到删除CMakeCache.txt, 我测试无效  issue链接: https://github.com/opencv/opencv/pull/8582
错误5(兼容问题):
error: Cannot code sign because the target does not have an Info.plist file and one is not being generated automatically. Apply an Info.plist file to the target using the INFOPLIST_FILE build setting or generate one automatically by setting the GENERATE_INFOPLIST_FILE build setting to YES (recommended). (in target 'CompilerIdC' from project 'CompilerIdC')
调整cmake版本为3.24.0😖
重新编译, 成功.
针对不熟悉C++的朋友, 比如我. 其实编译后的opencv都有封装成oc代码, 所以直接用就行了.  直接查看header里面, 很多封装好的oc对象, 参考下面几个头文件
#import "opencv2/opencv2.h"
#import "opencv2/imgcodecs/ios.h"  
#import "opencv2/imgproc/types_c.h"
#import "opencv2/imgproc/imgproc_c.h"
#import "opencv2/core/types_c.h"
Image和Mat对象的转换也是有的 (opencv2/imgcodecs/ios.h):
CV_EXPORTS CGImageRef MatToCGImage(const cv::Mat& image) CF_RETURNS_RETAINED;
CV_EXPORTS void CGImageToMat(const CGImageRef image, cv::Mat& m, bool alphaExist = false);
CV_EXPORTS UIImage* MatToUIImage(const cv::Mat& image);
CV_EXPORTS void UIImageToMat(const UIImage* image,
                            cv::Mat& m, bool alphaExist = false);
微信的那几个模型文件其实在编译时, 会自动给你下载 /Users/*******/Desktop/opencv-4.6.0/ios/build/build-arm64-iphoneos/downloads/wechat_qrcode:
**sr.prototxt**
**sr.caffemodel**
**detect.caffemodel**
**detect.prototxt**
OC简单使用:
NSString *path = [[NSBundle mainBundle] pathForResource:@"wechat_qrcode" ofType:@"bundle"];
WeChatQRCode  *wechatQRCode = [[WeChatQRCode alloc] initWithDetector_prototxt_path:[NSString stringWithFormat:@"%@/%@", path, @"detect.prototxt"] detector_caffe_model_path:[NSString stringWithFormat:@"%@/%@", path, @"detect.caffemodel"] super_resolution_prototxt_path:[NSString stringWithFormat:@"%@/%@", path, @"sr.prototxt"] super_resolution_caffe_model_path:[NSString stringWithFormat:@"%@/%@", path, @"sr.caffemodel"]];
Mat *mat = [[Mat alloc] init];
UIImageToMat(image, mat.nativeRef);
NSArray *results = [wechatQRCode detectAndDecode:mat];
参考链接:
opencv_wechat_qrcode文档
编译好的opencv2.framework, 密码:xxxx
这个东西只是识别二维码, 相机录制视频帧截取以及后续集成请自己努力. 同时感谢微信团队的开源, 让我们这些垃圾仔多摸鱼.