在黑色图像上叠加精明的边缘

Question

我有一些简单的代码，可以执行精明的边缘检测并将边缘覆盖在原始图像上。

代码是有效的，但我希望边缘是用黑色绘制的，目前它们是用白色绘制的。

static void sketchImage(Mat srcColor, Mat& dst, bool sketchMode, int debugType)
{
   Mat srcGray;
   Mat edgesBgr;
   cvtColor(srcColor, srcGray, CV_BGRA2GRAY);
   cvtColor(srcColor, srcColor, CV_BGRA2BGR);
   GaussianBlur(srcGray, srcGray, cvSize(5, 5),1.2,1.2);
   GaussianBlur(srcColor, srcColor, cvSize(5,5), 1.4, 1.4);
   CvSize size = srcColor.size();
   Mat edges = Mat(size, CV_8U);
   Canny(srcGray, edges, 150, 150);
   cvtColor(edges, edgesBgr, cv::COLOR_GRAY2BGR);
   dst = srcColor + edgesBgr;
}

我相信这很简单，但我是openCV的新手，我很感激任何帮助。

要求的完整代码：

#import "ViewController.h"
#import "opencv2/highgui.hpp"
#import "opencv2/core.hpp"
#import "opencv2/opencv.hpp"
#import "opencv2/imgproc.hpp"
@interface ViewController ()
@property (weak, nonatomic) IBOutlet UIImageView *display;
@property (strong, nonatomic) UIImage* image;
@property (strong, nonatomic) UIImage* backup;
@property NSInteger clickflag;
@end
@implementation ViewController
using namespace cv;
- (IBAction)convert_click:(id)sender {
NSLog(@"Clicked");
if (_clickflag == 0)
{
    cv::Mat cvImage, cvBWImage;
    UIImageToMat(_image, cvImage);
    //cv::cvtColor(cvImage, cvBWImage, CV_BGR2GRAY);
    //cvBWImage = cvImage;
    cartoonifyImage(cvImage, cvBWImage, false, 0);
    _image = MatToUIImage(cvBWImage);
    [_display setImage:_image];
    _clickflag = 1;
}
else if(_clickflag == 1)
{
    _image = _backup;
    [_display setImage:_image];
    _clickflag = 0;
}

}

static UIImage* MatToUIImage(const cv::Mat& m)
{
//CV_Assert(m.depth() == CV_8U);
NSData *data = [NSData dataWithBytes:m.data length:m.step*m.rows];
CGColorSpaceRef colorSpace = m.channels() == 1 ?
CGColorSpaceCreateDeviceGray() : CGColorSpaceCreateDeviceRGB();
CGDataProviderRef provider = CGDataProviderCreateWithCFData((__bridge CFDataRef)data);
// Creating CGImage from cv::Mat
CGImageRef imageRef = CGImageCreate(m.cols, m.rows, m.elemSize1()*8, m.elemSize()*8,
                                    m.step[0], colorSpace, kCGImageAlphaNoneSkipLast|kCGBitmapByteOrderDefault,
                                    provider, NULL, false, kCGRenderingIntentDefault);
UIImage *finalImage = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
CGDataProviderRelease(provider);
CGColorSpaceRelease(colorSpace);
return finalImage;
}
static void UIImageToMat(const UIImage* image, cv::Mat& m)
{
CGColorSpaceRef colorSpace = CGImageGetColorSpace(image.CGImage);
CGFloat cols = image.size.width;
CGFloat rows = image.size.height;
m.create(rows, cols, CV_8UC4); // 8 bits per component, 4 channels
CGContextRef contextRef = CGBitmapContextCreate(m.data, m.cols, m.rows, 8,
                                                m.step[0], colorSpace, kCGImageAlphaNoneSkipLast | kCGBitmapByteOrderDefault);
CGContextDrawImage(contextRef, CGRectMake(0, 0, cols, rows), image.CGImage);
CGContextRelease(contextRef);
}
static void sketchImage(Mat srcColor, Mat& dst, bool sketchMode, int debugType)

｛

Mat srcGray;
Mat edgesBgr;
cvtColor(srcColor, srcGray, CV_BGRA2GRAY);
cvtColor(srcColor, srcColor, CV_BGRA2BGR);
GaussianBlur(srcGray, srcGray, cvSize(5, 5),1.2,1.2);
GaussianBlur(srcColor, srcColor, cvSize(5,5), 1.4, 1.4);
CvSize size = srcColor.size();
Mat edges = Mat(size, CV_8U);
Canny(srcGray, edges, 150, 150);
cvtColor(edges, edgesBgr, cv::COLOR_GRAY2BGR);
//edgesBgr = edgesBgr.inv();
NSLog(@"%d, %dn", srcColor.size().height, srcColor.size().width);
NSLog(@"%d, %dn", edgesBgr.size().height, edgesBgr.size().width);
dst = edgesBgr + srcColor;
}


- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
_image = [UIImage imageNamed:@"Robben.jpg"];
_backup = [UIImage imageNamed:@"Robben.jpg"];
_clickflag = 0;
[_display setImage:_image];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end

Answer 1

static void sketchImage(Mat srcColor, Mat& dst, bool sketchMode, int debugType)
{
   Mat srcGray;
   cvtColor(srcColor, srcGray, CV_BGRA2GRAY);
   cvtColor(srcColor, srcColor, CV_BGRA2BGR);
   GaussianBlur(srcGray, srcGray, cvSize(5, 5),1.2,1.2);
   GaussianBlur(srcColor, srcColor, cvSize(5,5), 1.4, 1.4);
   CvSize size = srcColor.size();
   Mat edges = Mat(size, CV_8U);
   Canny(srcGray, edges, 150, 150);
   dst = srcColor.clone();
   dst.setTo(0,edges);
}

Answer 2

您可以应用bitwise_not(dst,dst)，使白色变为黑色，黑色变为白色！

void bitwise_not（InputArray src、OutputArray dst、InputArraymask=noArray（）