OpenCVとAVFoundationフレームワークを使用したiPhoneリアルタイム画像処理？

Question

openCVを使ってリアルタイムで画像処理をしたい。

最終目標は、リアルタイムで画面に結果を表示し、反対側のカメラはAVFoundationフレームワークを使用してビデオをキャプチャしています。

OpenCVですべてのビデオフレームを処理し、その結果をリアルタイムで画面に表示するにはどうすればよいですか？

Answer 1

使用AVAssertReader

//Setup Reader 
    AVURLAsset * asset = [AVURLAsset URLAssetWithURL:urlvalue options:nil]; 
    [asset loadValuesAsynchronouslyForKeys:[NSArray arrayWithObject:@"tracks"] completionHandler: ^{ dispatch_async(dispatch_get_main_queue(), ^{ 
     AVAssetTrack * videoTrack = nil; 
     NSArray * tracks = [asset tracksWithMediaType:AVMediaTypeVideo]; 
     if ([tracks count] == 1) { 
      videoTrack = [tracks objectAtIndex:0]; 
      NSError * error = nil; 
      _movieReader = [[AVAssetReader alloc] initWithAsset:asset error:&error]; 
      if (error) 
       NSLog(error.localizedDescription); 
      NSString* key = (NSString*)kCVPixelBufferPixelFormatTypeKey; 
      NSNumber* value = [NSNumber numberWithUnsignedInt:kCVPixelFormatType_4444AYpCbCr16]; NSDictionary* videoSettings = [NSDictionary dictionaryWithObject:value forKey:key]; 
      [_movieReader addOutput:[AVAssetReaderTrackOutput assetReaderTrackOutputWithTrack:videoTrack outputSettings:videoSettings]]; 
      [_movieReader startReading]; 

     } 
    }); 
    }]; 

、あなたがもう一度再起動する必要があなたの_movieReaderのリーチ終了後に次のムービーフレーム

static int frameCount=0; 
- (void) readNextMovieFrame { 

    if (_movieReader.status == AVAssetReaderStatusReading) { 

     AVAssetReaderTrackOutput * output = [_movieReader.outputs objectAtIndex:0]; 
     CMSampleBufferRef sampleBuffer = [output copyNextSampleBuffer]; 
     if (sampleBuffer) { 
      CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer); 
      // Lock the image buffer 
      CVPixelBufferLockBaseAddress(imageBuffer,0); 
      // Get information of the image 
      uint8_t *baseAddress = (uint8_t *)CVPixelBufferGetBaseAddress(imageBuffer); 
      size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer); 
      size_t width = CVPixelBufferGetWidth(imageBuffer); 
      size_t height = CVPixelBufferGetHeight(imageBuffer); 

      /*We unlock the image buffer*/ 
      CVPixelBufferUnlockBaseAddress(imageBuffer,0); 

      /*Create a CGImageRef from the CVImageBufferRef*/ 
      CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); 
      CGContextRef newContext = CGBitmapContextCreate(baseAddress, width, height, 8, bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst); 
      CGImageRef newImage = CGBitmapContextCreateImage(newContext); 

      /*We release some components*/ 
      CGContextRelease(newContext); 
      CGColorSpaceRelease(colorSpace); 

      /*We display the result on the custom layer*/ 
      /*self.customLayer.contents = (id) newImage;*/ 

      /*We display the result on the image view (We need to change the orientation of the image so that the video is displayed correctly)*/ 
      UIImage *image= [UIImage imageWithCGImage:newImage scale:0.0 orientation:UIImageOrientationRight]; 
      UIGraphicsBeginImageContext(image.size); 

      [image drawAtPoint:CGPointMake(0, 0)]; 

      // UIImage *img=UIGraphicsGetImageFromCurrentImageContext(); 
      videoImage=UIGraphicsGetImageFromCurrentImageContext(); 

      UIGraphicsEndImageContext(); 


//videoImage=image; 

      // if (frameCount < 40) { 
       NSLog(@"readNextMovieFrame==%d",frameCount); 
         NSString* filename = [NSString stringWithFormat:@"Documents/frame_%d.png", frameCount]; 
         NSString* pngPath = [NSHomeDirectory() stringByAppendingPathComponent:filename]; 
        [UIImagePNGRepresentation(videoImage) writeToFile: pngPath atomically: YES]; 
        frameCount++; 
     //  } 

      CVPixelBufferUnlockBaseAddress(imageBuffer,0); 
      CFRelease(sampleBuffer); 
     } 
    } 
} 

を取得します。