pantalla - Captura de imagen fija con iOS usando CVVideoCamera(OpenCV)

como hacer screenshot en iphone xr

Question

Uso opencv 2.4.9 para iOS y necesito ayuda.

Me gustaría capturar con CVVideoCamera durante la filmación de fotos de alta resolución. Necesito la cámara de video para el método de imagen de proceso para agregar una captura de documentos maduros a través de la detección de bordes. Esto también funciona muy bien, pero necesito una foto de la foto de alta resolución reconocida del documento una vez que se haya detectado el documento.

Encontré este http://code.opencv.org/svn/gsoc2012/ios/trunk/HelloWorld_iOS/HelloWorld_iOS/VideoCameraController.m

esto funciona con foto y video por el mismo tiempo, pero el método de la imagen del proceso es diferente al del delegado cvvideocamera y mi algorithmus no funciona con esta clase: - /

Pero busco esta solución de videocámara / cámara de video para CVVideoCamera en OpenCV.

Espero por ayuda y perdón por mi inglés

Answer 1

cvVideoCamera este problema añadiendo algunos métodos de la clase cvPhotoCamera clase cvPhotoCamera . Funciona para mí, pero tal vez necesite algunas mejoras aplicadas a su código.

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