我在真正的iPhone上使用OpenCV库裁剪图像时遇到问题。
我有一个选定区域的图像,我想对这个区域的图像应用透视变换。这在模拟器上工作正常但在iphone上新图像没有映射到矩形,新图像也是蓝色。
这是我的代码:
+ (IplImage *)CreateIplImageFromUIImage:(UIImage *)image {
// Getting CGImage from UIImage
CGImageRef imageRef = image.CGImage;
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
// Creating temporal IplImage for drawing
IplImage *iplimage = cvCreateImage(
cvSize(image.size.width,image.size.height), IPL_DEPTH_8U, 4
);
// Creating CGContext for temporal IplImage
CGContextRef contextRef = CGBitmapContextCreate(
iplimage->imageData, iplimage->width, iplimage->height,
iplimage->depth, iplimage->widthStep,
colorSpace, kCGImageAlphaPremultipliedLast|kCGBitmapByteOrderDefault
);
// Drawing CGImage to CGContext
CGContextDrawImage(
contextRef,
CGRectMake(0, 0, image.size.width, image.size.height),
imageRef
);
CGContextRelease(contextRef);
CGColorSpaceRelease(colorSpace);
// Creating result IplImage
IplImage *ret = cvCreateImage(cvGetSize(iplimage), IPL_DEPTH_8U, 3);
cvCvtColor(iplimage, ret, CV_RGBA2BGR);
cvReleaseImage(&iplimage);
return ret;
}
+ (UIImage *)UIImageFromIplImage:(IplImage *)img {
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
// Creating result IplImage
IplImage *image = cvCreateImage(cvGetSize(img), IPL_DEPTH_8U, 4);
cvCvtColor(img, image, CV_BGR2RGBA);
// Allocating the buffer for CGImage
NSData *data =
[NSData dataWithBytes:image->imageData length:image->imageSize];
CGDataProviderRef provider =
CGDataProviderCreateWithCFData((CFDataRef)data);
// Creating CGImage from chunk of IplImage
CGImageRef imageRef = CGImageCreate(
image->width, image->height,
image->depth, image->depth * image->nChannels, image->widthStep,
colorSpace, kCGImageAlphaNone|kCGBitmapByteOrderDefault,
provider, NULL, false, kCGRenderingIntentDefault
);
// Getting UIImage from CGImage
UIImage *ret = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
CGDataProviderRelease(provider);
CGColorSpaceRelease(colorSpace);
return ret;
}
+ (UIImage *)perspectiveTransform: (UIImage*) originalImage :(CGFloat) h :(CGFloat) w :(CGPoint) point1 :(CGPoint) point2 :(CGPoint) point3 :(CGPoint) point4
{
CvPoint2D32f srcQuad[4];
srcQuad[0].x = point1.x;
srcQuad[0].y = point1.y;
srcQuad[1].x = point2.x;
srcQuad[1].y = point2.y;
srcQuad[2].x = point3.x;
srcQuad[2].y = point3.y;
srcQuad[3].x = point4.x;
srcQuad[3].y = point4.y;
IplImage *src = [self CreateIplImageFromUIImage:originalImage];
IplImage *dst = cvCreateImage(cvGetSize(src),
src->depth,
src->nChannels);
cvZero(dst);
CGFloat width = src->width;
CGFloat height = src->height;
CvMat* mmat = cvCreateMat(3, 3, CV_32FC1);
CvPoint2D32f *c1 = (CvPoint2D32f *)malloc(4 * sizeof(CvPoint2D32f));
CvPoint2D32f *c2 = (CvPoint2D32f *)malloc(4 * sizeof(CvPoint2D32f));
c1[0].x = round((width/w)*srcQuad[0].x); c1[0].y = round((height/h)*srcQuad[0].y);
c1[1].x = round((width/w)*srcQuad[1].x); c1[1].y = round((height/h)*srcQuad[1].y);
c1[2].x = round((width/w)*srcQuad[2].x); c1[2].y = round((height/h)*srcQuad[2].y);
c1[3].x = round((width/w)*srcQuad[3].x); c1[3].y = round((height/h)*srcQuad[3].y);
c2[0].x = 0; c2[0].y = 0;
c2[1].x = width - 1; c2[1].y = 0;
c2[2].x = 0; c2[2].y = height - 1;
c2[3].x = width - 1; c2[3].y = height - 1;
mmat = cvGetPerspectiveTransform(c1, c2, mmat);
free(c1);
free(c2);
cvWarpPerspective(src, dst, mmat, CV_INTER_LINEAR+CV_WARP_FILL_OUTLIERS, cvScalarAll(0));
cvReleaseImage(&src);
cvReleaseMat(&mmat);
UIImage *newImage = [self UIImageFromIplImage:dst];
cvReleaseImage(&dst);
return newImage;
}
感谢您的帮助!