由于最近做项目要使用opencv的原因，需要使用到这个功能
是要将image 转成 cv::Mat 识别
- (cv::Mat)cvMatFromUIImage:(UIImage*)image{
@autoreleasepool {
CGColorSpaceRef colorSpace = CGImageGetColorSpace(image.CGImage);
CGFloatcols = image.size.width;
CGFloatrows = image.size.height;
cv::Mat cvMat(rows, cols, CV_8UC4); // 8 bits per component, 4 channels (color channels + alpha)
CGContextRefcontextRef =CGBitmapContextCreate(cvMat.data, // Pointer to data
cols, // Width of bitmap
rows, // Height of bitmap
8, // Bits per component
cvMat.step[0], // Bytes per row
colorSpace, // Colorspace
// kCGImageAlphaNoneSkipLast |kCGBitmapByteOrderDefault // 此处有修改适配laplacian的接入色值转换
kCGBitmapByteOrder32Little|kCGImageAlphaPremultipliedFirst);// Bitmap info flags
CGContextDrawImage(contextRef,CGRectMake(0,0, cols, rows), image.CGImage);
CGColorSpaceRelease(colorSpace);
CGContextRelease(contextRef);
colorSpace =NULL;
contextRef =NULL;
returncvMat;
}
}
而且这个方法要频繁使用，会导致内存不断飙升，最终闪退。使用了@autoreleasepool {} 和 CGColorSpaceRelease(colorSpace); CGContextRelease(contextRef); 释放内存和管理，都发现没用，很崩溃！目前似乎都还没解决成功。
最终使用了其他方式：UIImage --> base64 --> CVMat 完美解决了。但是识别率下降了
代码如下
-(NSString *)UIImageToBase64Str:(UIImage *) image{
NSData *data = UIImagePNGRepresentation(image);
NSString* str = [database64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
return str;
}
static cv::MatBase2Mat(std::string&base64_data) {
cv::Mat img;
std::strings_mat;
s_mat =base64Decode(base64_data.data(), base64_data.size());
std::vector base64_img(s_mat.begin(), s_mat.end());
img =cv::imdecode(base64_img, CV_LOAD_IMAGE_COLOR);
return img;
}
staticstd::stringbase64Decode(constchar* Data,intDataByte) {
//解码表
constcharDecodeTable[] =
{
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
62,// '+'
0,0,0,
63,// '/'
52,53,54,55,56,57,58,59,60,61,// '0'-'9'
0,0,0,0,0,0,0,
0,1,2,3,4,5,6,7,8,9,10,11,12,
13,14,15,16,17,18,19,20,21,22,23,24,25,// 'A'-'Z'
0,0,0,0,0,0,
26,27,28,29,30,31,32,33,34,35,36,37,38,
39,40,41,42,43,44,45,46,47,48,49,50,51,// 'a'-'z'
};
std::stringstrDecode;
intnValue;
inti =0;
while(i < DataByte) {
if(*Data !='\r'&& *Data !='\n') {
nValue = DecodeTable[*Data++] <<18;
nValue += DecodeTable[*Data++] <<12;
strDecode += (nValue &0x00FF0000) >>16;
if(*Data !='=') {
nValue += DecodeTable[*Data++] <<6;
strDecode += (nValue &0x0000FF00) >>8;
if(*Data !='=') {
nValue += DecodeTable[*Data++];
strDecode += nValue &0x000000FF;
}
}
i +=4;
}
else{
Data++;
i++;
}
}
returnstrDecode;
}
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