使用CVVideoCamera（OpenCV）进行iOS静态图像捕获 [英] iOS Still Image Capture Using CVVideoCamera (OpenCV)

问题描述

我在iOS上使用opencv 2.4.9并需要帮助。

I use opencv 2.4.9 for iOS and need help.

我想在拍摄高分辨率照片时使用CVVideoCamera拍摄。我需要用于过程图像方法的摄像机通过边缘检测添加成熟的文档捕获。这也很好用，但是一旦检测到文件，我需要一张公认的高分辨率照片的照片。

I would like to capture with CVVideoCamera during filming high-resolution photos. I need the video camera for the process image method to add a mature document capture via edge detection. This works great as well but i need a photo of the recognized high-resolution photo of the document once the document has been detected.

我发现这个 http://code.opencv.org/svn/gsoc2012/ios/trunk/ HelloWorld_iOS / HelloWorld_iOS / VideoCameraController.m

这同时适用于照片和视频，但过程图像方法与cvvideocamera委托不同我的算法不适用于这个类： - /

this works with photo and Video for the same time, but the process image Method is different as the from the cvvideocamera delegate and my algorithmus dont work with this class :- /

但我在OpenCV中搜索CVVideoCamera的photocamera / videocamera解决方案。

But i search this photocamera/videocamera solution for CVVideoCamera in OpenCV.

希望得到帮助，对不起我的英语

Hope for help and sorry for my english

推荐答案

我解决了此问题将 cvVideoCamera 类的一些方法添加到 cvPhotoCamera 类。它适用于我，但可能需要对你的代码进行一些改进。

I solved this problem adding some methods of cvVideoCamera class to cvPhotoCamera class. It works for me, but maybe need some improvements applying to you code.

CvPhotoCameraMod.h：

#import <UIKit/UIKit.h>
#import <opencv2/highgui/cap_ios.h>
#import <opencv2/highgui/ios.h>

#define DEGREES_RADIANS(angle) ((angle) / 180.0 * M_PI)

@class CvPhotoCameraMod;

@protocol CvPhotoCameraDelegateMod <CvPhotoCameraDelegate>
- (void)processImage:(cv::Mat&)image;
@end

@interface CvPhotoCameraMod : CvPhotoCamera <AVCaptureVideoDataOutputSampleBufferDelegate>

@property (nonatomic, retain) CALayer *customPreviewLayer;
@property (nonatomic, retain) AVCaptureVideoDataOutput *videoDataOutput;
@property (nonatomic, weak) id <CvPhotoCameraDelegateMod> delegate;

- (void)createCustomVideoPreview;

@end

CvPhotoCameraMod.mm：

#import "CvPhotoCameraMod.h"
#import <CoreGraphics/CoreGraphics.h>
#define DEGREES_RADIANS(angle) ((angle) / 180.0 * M_PI)

@implementation CvPhotoCameraMod


-(void)createCaptureOutput;
{
    [super createCaptureOutput];
    [self createVideoDataOutput];
}
- (void)createCustomVideoPreview;
{
    [self.parentView.layer addSublayer:self.customPreviewLayer];
}


//Method mostly taken from this source: https://github.com/Itseez/opencv/blob/b46719b0931b256ab68d5f833b8fadd83737ddd1/modules/videoio/src/cap_ios_video_camera.mm

-(void)createVideoDataOutput{
    // Make a video data output
    self.videoDataOutput = [AVCaptureVideoDataOutput new];

    //Drop grayscale support here
    self.videoDataOutput.videoSettings  = [NSDictionary dictionaryWithObject:[NSNumber numberWithUnsignedInt:kCVPixelFormatType_32BGRA] forKey:(id)kCVPixelBufferPixelFormatTypeKey];


    // discard if the data output queue is blocked (as we process the still image)
    [self.videoDataOutput setAlwaysDiscardsLateVideoFrames:YES];
    if ( [self.captureSession canAddOutput:self.videoDataOutput] ) {
        [self.captureSession addOutput:self.videoDataOutput];
    }
    [[self.videoDataOutput connectionWithMediaType:AVMediaTypeVideo] setEnabled:YES];

    // set video mirroring for front camera (more intuitive)
    if ([self.videoDataOutput connectionWithMediaType:AVMediaTypeVideo].supportsVideoMirroring) {
        if (self.defaultAVCaptureDevicePosition == AVCaptureDevicePositionFront) {
            [self.videoDataOutput connectionWithMediaType:AVMediaTypeVideo].videoMirrored = YES;
        } else {
            [self.videoDataOutput connectionWithMediaType:AVMediaTypeVideo].videoMirrored = NO;
        }
    }

    // set default video orientation
    if ([self.videoDataOutput connectionWithMediaType:AVMediaTypeVideo].supportsVideoOrientation) {
        [self.videoDataOutput connectionWithMediaType:AVMediaTypeVideo].videoOrientation = self.defaultAVCaptureVideoOrientation;
    }

    // create a custom preview layer
    self.customPreviewLayer = [CALayer layer];

    self.customPreviewLayer.bounds = CGRectMake(0, 0, self.parentView.frame.size.width, self.parentView.frame.size.height);

    self.customPreviewLayer.position = CGPointMake(self.parentView.frame.size.width/2., self.parentView.frame.size.height/2.);

    // create a serial dispatch queue used for the sample buffer delegate as well as when a still image is captured
    // a serial dispatch queue must be used to guarantee that video frames will be delivered in order
    // see the header doc for setSampleBufferDelegate:queue: for more information
    dispatch_queue_t videoDataOutputQueue = dispatch_queue_create("VideoDataOutputQueue", DISPATCH_QUEUE_SERIAL);
    [self.videoDataOutput setSampleBufferDelegate:self queue:videoDataOutputQueue];
}

- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection
{
    (void)captureOutput;
    (void)connection;
    if (self.delegate) {

        // convert from Core Media to Core Video
        CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
        CVPixelBufferLockBaseAddress(imageBuffer, 0);

        void* bufferAddress;
        size_t width;
        size_t height;
        size_t bytesPerRow;

        CGColorSpaceRef colorSpace;
        CGContextRef context;

        int format_opencv;

        OSType format = CVPixelBufferGetPixelFormatType(imageBuffer);
        if (format == kCVPixelFormatType_420YpCbCr8BiPlanarFullRange) {

            format_opencv = CV_8UC1;

            bufferAddress = CVPixelBufferGetBaseAddressOfPlane(imageBuffer, 0);
            width = CVPixelBufferGetWidthOfPlane(imageBuffer, 0);
            height = CVPixelBufferGetHeightOfPlane(imageBuffer, 0);
            bytesPerRow = CVPixelBufferGetBytesPerRowOfPlane(imageBuffer, 0);

        } else { // expect kCVPixelFormatType_32BGRA

            format_opencv = CV_8UC4;

            bufferAddress = CVPixelBufferGetBaseAddress(imageBuffer);
            width = CVPixelBufferGetWidth(imageBuffer);
            height = CVPixelBufferGetHeight(imageBuffer);
            bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);

        }

        // delegate image processing to the delegate
        cv::Mat image((int)height, (int)width, format_opencv, bufferAddress, bytesPerRow);

        CGImage* dstImage;

        if ([self.delegate respondsToSelector:@selector(processImage:)]) {
            [self.delegate processImage:image];
        }

        // check if matrix data pointer or dimensions were changed by the delegate
        bool iOSimage = false;
        if (height == (size_t)image.rows && width == (size_t)image.cols && format_opencv == image.type() && bufferAddress == image.data && bytesPerRow == image.step) {
            iOSimage = true;
        }


        // (create color space, create graphics context, render buffer)
        CGBitmapInfo bitmapInfo;

        // basically we decide if it's a grayscale, rgb or rgba image
        if (image.channels() == 1) {
            colorSpace = CGColorSpaceCreateDeviceGray();
            bitmapInfo = kCGImageAlphaNone;
        } else if (image.channels() == 3) {
            colorSpace = CGColorSpaceCreateDeviceRGB();
            bitmapInfo = kCGImageAlphaNone;
            if (iOSimage) {
                bitmapInfo |= kCGBitmapByteOrder32Little;
            } else {
                bitmapInfo |= kCGBitmapByteOrder32Big;
            }
        } else {
            colorSpace = CGColorSpaceCreateDeviceRGB();
            bitmapInfo = kCGImageAlphaPremultipliedFirst;
            if (iOSimage) {
                bitmapInfo |= kCGBitmapByteOrder32Little;
            } else {
                bitmapInfo |= kCGBitmapByteOrder32Big;
            }
        }

        if (iOSimage) {
            context = CGBitmapContextCreate(bufferAddress, width, height, 8, bytesPerRow, colorSpace, bitmapInfo);
            dstImage = CGBitmapContextCreateImage(context);
            CGContextRelease(context);
        } else {

            NSData *data = [NSData dataWithBytes:image.data length:image.elemSize()*image.total()];
            CGDataProviderRef provider = CGDataProviderCreateWithCFData((__bridge CFDataRef)data);

            // Creating CGImage from cv::Mat
            dstImage = CGImageCreate(image.cols,                                 // width
                                     image.rows,                                 // height
                                     8,                                          // bits per component
                                     8 * image.elemSize(),                       // bits per pixel
                                     image.step,                                 // bytesPerRow
                                     colorSpace,                                 // colorspace
                                     bitmapInfo,                                 // bitmap info
                                     provider,                                   // CGDataProviderRef
                                     NULL,                                       // decode
                                     false,                                      // should interpolate
                                     kCGRenderingIntentDefault                   // intent
                                     );

            CGDataProviderRelease(provider);
        }


        // render buffer
        dispatch_sync(dispatch_get_main_queue(), ^{
            self.customPreviewLayer.contents = (__bridge id)dstImage;
        });


        // cleanup
        CGImageRelease(dstImage);

        CGColorSpaceRelease(colorSpace);

        CVPixelBufferUnlockBaseAddress(imageBuffer, 0);
    }
}


@end

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