文档扫描仪iOS OpenCV [英] Document Scanner iOS OpenCV
问题描述
在这里,我尝试使用iOS中的OpenCV库在扫描图像后对其进行处理.但是我无法让您知道如何在imread()函数中传递图像源.
Here I'm trying to process image after scanning it, using OpenCV library in iOS. But I am unable you figure out how to pass image source in imread() function.
我必须通过的图像输入在下面的行中:-
the input for image that I have to pass is in below line :-
cv :: Mat输入= cv :: imread("tesy1.jpeg",IMREAD_UNCHANGED);
cv::Mat input = cv::imread("tesy1.jpeg", IMREAD_UNCHANGED );
究竟如何使用imread()函数传递图像?
Exactly how to use imread() fuction to pass image?
有人可以帮我吗?
//我的代码 +(cv :: Mat)cvMatFromUIImage2:(UIImage *)图像 {
//My code + (cv::Mat)cvMatFromUIImage2:(UIImage*)image {
cv::Mat input = cv::imread("tesy1.jpeg", IMREAD_UNCHANGED );
int maxdim = input.cols; //std::max(input.rows,input.cols);
const int dim = 1024;
if ( maxdim > dim )
{
double scale = (double)dim/(double)maxdim;
cv::Mat t;
cv::resize( input, t, cv::Size(), scale,scale );
input = t;
}
if ( input.type()!=CV_8UC3 )
CV_Error(CV_HAL_ERROR_UNKNOWN,"!bgr");
cv::Mat result;
input.copyTo( result ); // result is just for drawing the text rectangles
cv::Mat median;
cv::medianBlur(input,median,5);
cv::Mat localmax;
// find local maximum
cv::Mat kernel = cv::getStructuringElement(cv::MORPH_RECT,cv::Size(15,15) );
cv::morphologyEx( median,localmax,cv::MORPH_CLOSE,kernel,cv::Point(-1,-1),1,cv::BORDER_REFLECT101 );
std::vector< cv::Rect > bb;
// detectLetters by @William, modified to internally do the grayscale conversion if necessary
// https://stackoverflow.com/questions/23506105/extracting-text-opencv?rq=1
// detectLetters( input, bb );
// compose a simple Gaussian model for text background (still assumed white)
cv::Mat mask( input.size(),CV_8UC1,cv::Scalar( 0 ) );
if ( bb.empty() )
return input; // TODO; none found
for ( size_t i=0;i<bb.size(); ++i )
{
cv::rectangle( result, bb[i], cv::Scalar(0,0,255),2,8 ); // visualize only
cv::rectangle( mask, bb[i], cv::Scalar( 1 ), -1 ); // create a mask for cv::meanStdDev
}
cv::Mat mean,dev;
cv::meanStdDev( localmax, mean, dev, mask );
if ( mean.type()!=CV_64FC1 || dev.type()!=CV_64FC1 || mean.size()!=cv::Size(1,3) || dev.size()!=cv::Size(1,3) )
CV_Error(CV_HAL_ERROR_UNKNOWN, "should never happen");
double minimum[3];
double maximum[3];
// simply truncate the localmax according to our simple Gaussian model (+/- one standard deviation)
for ( unsigned int u=0;u<3;++u )
{
minimum[u] = mean.at<double>(u ) - dev.at<double>( u );
maximum[u] = mean.at<double>(u ) + dev.at<double>( u );
}
for ( int y=0;y<mask.rows;++y){
for ( int x=0;x<mask.cols;++x){
cv::Vec3b & col = localmax.at<cv::Vec3b>(y,x);
for ( unsigned int u=0;u<3;++u )
{
if ( col[u]>maximum[u] )
col[u]=maximum[u];
else if ( col[u]<minimum[u] )
col[u]=minimum[u];
}
}
}
// do the per pixel gain then
cv::Mat dst;
input.copyTo( dst );
for ( int y=0;y<input.rows;++y){
for ( int x=0;x<input.cols;++x){
const cv::Vec3b & v1=input.at<cv::Vec3b>(y,x);
const cv::Vec3b & v2=localmax.at<cv::Vec3b>(y,x);
cv::Vec3b & v3=dst.at<cv::Vec3b>(y,x);
for ( int i=0;i<3;++i )
{
double gain = 255.0/(double)v2[i];
v3[i] = cv::saturate_cast<unsigned char>( gain * v1[i] );
}
}
}
// and dst is the result
return dst;
}
推荐答案
最后解决了问题,我找到了解决方案.需要首先将图像转换为cv:Mat
Finally issue is sorted out,I got the solution. Need to first convert image into cv:Mat
参考文献:-扫描的文档-文本&使用OpenCV + iOS时背景清晰度不好
下面的方法会将UIImage转换为cvMat
Below method will convert UIImage to cvMat
+(cv::Mat)cvMatFromUIImage:(UIImage*)image
{
CGColorSpaceRef colorSpace = CGImageGetColorSpace(image.CGImage);
CGFloat cols = image.size.width;
CGFloat rows = image.size.height;
cv::Mat cvMat(rows, cols, CV_8UC4); // 8 bits per component, 4 channels (color channels + alpha)
CGContextRef contextRef = CGBitmapContextCreate(cvMat.data,
cols,
rows,
8,
cvMat.step[0],
colorSpace,
kCGImageAlphaNoneSkipLast
| kCGBitmapByteOrderDefault);
CGContextDrawImage(contextRef, CGRectMake(0, 0, cols, rows), image.CGImage);
CGContextRelease(contextRef);
return cvMat;
}
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