Recadrer l'image avec OpenCV

Question

J'ai un problème avec le rognage de l'image en utilisant la bibliothèque OpenCV sur iPhone. J'ai une image avec la zone sélectionnée et je voudrais recadrer l'image avec cette zone. Mais la nouvelle image n'est pas carte au rectangle et la nouvelle image a aussi la couleur bleue du texte.

J'utiliser ce code à l'image des cultures:

IplImage *src = [OpenCV CreateIplImageFromUIImage:image]; 


NSValue *val = [corners objectAtIndex:0]; 
CGPoint p1 = [val CGPointValue]; 
val = [corners objectAtIndex:1]; 
CGPoint p2 = [val CGPointValue]; 
val = [corners objectAtIndex:2]; 
CGPoint p3 = [val CGPointValue]; 
val = [corners objectAtIndex:3]; 
CGPoint p4 = [val CGPointValue]; 

float minX = fmin(fmin(p1.x, p2.x), fmin(p3.x, p4.x)); 
float minY = fmin(fmin(p1.y, p2.y), fmin(p3.y, p4.y)); 
float maxX = fmax(fmax(p1.x, p2.x), fmax(p3.x, p4.x)); 
float maxY = fmax(fmax(p1.y, p2.y), fmax(p3.y, p4.y)); 

CGFloat width = maxX - minX; 
CGFloat height = maxY - minY; 

IplImage *dst = cvCreateImage(cvSize(width, height), 8, 3); 

p1 = CGPointMake(p1.x - minX, p1.y - minY); 
p2 = CGPointMake(p2.x - minX, p2.y - minY); 
p3 = CGPointMake(p3.x - minX, p3.y - minY); 
p4 = CGPointMake(p4.x - minX, p4.y - minY); 

IplImage* cropped = cvCreateImage(cvSize(width, height), src->depth, src->nChannels); 

cvSetImageROI(src, cvRect(minX, minY, width, height)); 

cvCopy(src, cropped, NULL); 
cvResetImageROI(src); 
cvReleaseImage(&src); 

CvMat* mmat = cvCreateMat(3, 3, CV_32FC1); 

CvPoint2D32f *c1 = (CvPoint2D32f *)malloc(4 * sizeof(CvPoint2D32f)); 
CvPoint2D32f *c2 = (CvPoint2D32f *)malloc(4 * sizeof(CvPoint2D32f)); 

c1[0].x = p1.x; c1[0].y = p1.y; 
c1[1].x = p4.x; c1[1].y = p4.y; 
c1[2].x = p2.x; c1[2].y = p2.y; 
c1[3].x = p3.y; c1[3].y = p3.y; 

c2[0].x = 0; c2[0].y = 0; 
c2[1].x = width; c2[1].y = 0; 
c2[2].x = 0; c2[2].y = height; 
c2[3].x = width; c2[3].y = height; 

    mmat = cvGetPerspectiveTransform(c1, c2, mmat); 
cvWarpPerspective(cropped, dst, mmat, CV_INTER_LINEAR+CV_WARP_FILL_OUTLIERS, cvScalarAll(0)); 

Je serai reconnaissant pour toute aide.

Answer 1

J'ai eu une erreur dans mon code. Si quelqu'un est intéressé, voici le code de travail:

IplImage *src = [OpenCV CreateIplImageFromUIImage:image]; 

IplImage *dst = cvCloneImage(src); 
dst->origin = src->origin; 
dst->nChannels = src->nChannels; 
dst->depth = src->depth; 

cvZero(dst); 

NSValue *val = [corners objectAtIndex:0]; 
CGPoint p1 = [val CGPointValue]; 
val = [corners objectAtIndex:1]; 
CGPoint p2 = [val CGPointValue]; 
val = [corners objectAtIndex:2]; 
CGPoint p3 = [val CGPointValue]; 
val = [corners objectAtIndex:3]; 
CGPoint p4 = [val CGPointValue]; 

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(p1.x); c1[0].y = round(p1.y); 
c1[1].x = round(p4.x); c1[1].y = round(p4.y); 
c1[2].x = round(p2.x); c1[2].y = round(p2.y); 
c1[3].x = round(p3.x); c1[3].y = round(p3.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 = [OpenCV UIImageFromIplImage:dst]; 
cvReleaseImage(&dst);