【发布时间】：2017-03-01 18:37:00
【问题描述】：
所以我正在使用一些在 Objective C 中执行此操作的代码，我一直在将其转换为 swift，我正在努力从 AVCaptureStillImageOutput 创建一个 CIImage。因此，如果有人可以查看这段代码并告诉我哪里出错了，那就太好了。
这是 Objective C 代码
- (void)captureImageWithCompletionHander:(void(^)(NSString *fullPath))completionHandler
{
dispatch_suspend(_captureQueue);
AVCaptureConnection *videoConnection = nil;
for (AVCaptureConnection *connection in self.stillImageOutput.connections)
{
for (AVCaptureInputPort *port in connection.inputPorts)
{
if ([port.mediaType isEqual:AVMediaTypeVideo] )
{
videoConnection = connection;
break;
}
}
if (videoConnection) break;
}
__weak typeof(self) weakSelf = self;
[self.stillImageOutput captureStillImageAsynchronouslyFromConnection:videoConnection completionHandler: ^(CMSampleBufferRef imageSampleBuffer, NSError *error)
{
if (error)
{
dispatch_resume(_captureQueue);
return;
}
__block NSArray *filePath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); //create an array and store result of our search for the documents directory in it
NSString *documentsDirectory = [filePath objectAtIndex:0]; //create NSString object, that holds our exact path to the documents directory
NSString *fullPath = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"/iScan_img_%i.pdf",(int)[NSDate date].timeIntervalSince1970]];
@autoreleasepool
{
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer];
CIImage *enhancedImage = [[CIImage alloc] initWithData:imageData options:@{kCIImageColorSpace:[NSNull null]}];
imageData = nil;
if (weakSelf.cameraViewType == DocScannerCameraViewTypeBlackAndWhite)
{
enhancedImage = [self filteredImageUsingEnhanceFilterOnImage:enhancedImage];
}
else
{
enhancedImage = [self filteredImageUsingContrastFilterOnImage:enhancedImage];
}
if (weakSelf.isBorderDetectionEnabled && rectangleDetectionConfidenceHighEnough(_imageDedectionConfidence))
{
CIRectangleFeature *rectangleFeature = [self biggestRectangleInRectangles:[[self highAccuracyRectangleDetector] featuresInImage:enhancedImage]];
if (rectangleFeature)
{
enhancedImage = [self correctPerspectiveForImage:enhancedImage withFeatures:rectangleFeature];
}
}
CIFilter *transform = [CIFilter filterWithName:@"CIAffineTransform"];
[transform setValue:enhancedImage forKey:kCIInputImageKey];
NSValue *rotation = [NSValue valueWithCGAffineTransform:CGAffineTransformMakeRotation(-90 * (M_PI/180))];
[transform setValue:rotation forKey:@"inputTransform"];
enhancedImage = transform.outputImage;
if (!enhancedImage || CGRectIsEmpty(enhancedImage.extent)) return;
static CIContext *ctx = nil;
if (!ctx)
{
ctx = [CIContext contextWithOptions:@{kCIContextWorkingColorSpace:[NSNull null]}];
}
CGSize bounds = enhancedImage.extent.size;
bounds = CGSizeMake(floorf(bounds.width / 4) * 4,floorf(bounds.height / 4) * 4);
CGRect extent = CGRectMake(enhancedImage.extent.origin.x, enhancedImage.extent.origin.y, bounds.width, bounds.height);
static int bytesPerPixel = 8;
uint rowBytes = bytesPerPixel * bounds.width;
uint totalBytes = rowBytes * bounds.height;
uint8_t *byteBuffer = malloc(totalBytes);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
[ctx render:enhancedImage toBitmap:byteBuffer rowBytes:rowBytes bounds:extent format:kCIFormatRGBA8 colorSpace:colorSpace];
CGContextRef bitmapContext = CGBitmapContextCreate(byteBuffer,bounds.width,bounds.height,bytesPerPixel,rowBytes,colorSpace,kCGImageAlphaNoneSkipLast);
CGImageRef imgRef = CGBitmapContextCreateImage(bitmapContext);
CGColorSpaceRelease(colorSpace);
CGContextRelease(bitmapContext);
free(byteBuffer);
if (imgRef == NULL)
{
CFRelease(imgRef);
return;
}
saveCGImageAsJPEGToFilePath(imgRef, fullPath);
CFRelease(imgRef);
dispatch_async(dispatch_get_main_queue(), ^
{
completionHandler(fullPath);
dispatch_resume(_captureQueue);
});
_imageDedectionConfidence = 0.0f;
}
}];
}
现在基本上它会捕获内容，如果某些if 语句为真，那么它会捕获显示的CIRectangleFeature 中的内容，然后将CIImage 转换为CGImage 以在保存函数中调用。
我已经把它翻译成这样了。
func captureImage(completionHandler: @escaping (_ imageFilePath: String) -> Void) {
self.captureQueue?.suspend()
var videoConnection: AVCaptureConnection!
for connection in self.stillImageOutput.connections{
for port in (connection as! AVCaptureConnection).inputPorts {
if (port as! AVCaptureInputPort).mediaType.isEqual(AVMediaTypeVideo) {
videoConnection = connection as! AVCaptureConnection
break
}
}
if videoConnection != nil {
break
}
}
weak var weakSelf = self
self.stillImageOutput.captureStillImageAsynchronously(from: videoConnection) { (sampleBuffer, error) -> Void in
if error != nil {
self.captureQueue?.resume()
return
}
let filePath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
let documentsDirectory: String = filePath[0]
let fullPath: String = URL(fileURLWithPath: documentsDirectory).appendingPathComponent("iScan_img_\(Int(Date().timeIntervalSince1970)).pdf").absoluteString
autoreleasepool {
let imageData = Data(AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(sampleBuffer))
var enhancedImage = CIImage(data: imageData, options: [kCIImageColorSpace: NSNull()])
if weakSelf?.cameraViewType == DocScannerCameraViewType.blackAndWhite {
enhancedImage = self.filteredImageUsingEnhanceFilter(on: enhancedImage!)
}
else {
enhancedImage = self.filteredImageUsingContrastFilter(on: enhancedImage!)
}
if (weakSelf?.isEnableBorderDetection == true) && self.rectangleDetectionConfidenceHighEnough(confidence: self.imageDedectionConfidence) {
let rectangleFeature: CIRectangleFeature? = self.biggestRectangles(rectangles: self.highAccuracyRectangleDetector().features(in: enhancedImage!))
if rectangleFeature != nil {
enhancedImage = self.correctPerspective(for: enhancedImage!, withFeatures: rectangleFeature!)
}
}
let transform = CIFilter(name: "CIAffineTransform")
let rotation = NSValue(cgAffineTransform: CGAffineTransform(rotationAngle: -90 * (.pi / 180)))
transform?.setValue(rotation, forKey: "inputTransform")
enhancedImage = transform?.outputImage
if (enhancedImage == nil) || (enhancedImage?.extent.isEmpty)! {
return
}
var ctx: CIContext?
if (ctx != nil) {
ctx = CIContext(options: [kCIContextWorkingColorSpace: NSNull()])
}
var bounds: CGSize = (enhancedImage?.extent.size)!
bounds = CGSize(width: CGFloat((floorf(Float(bounds.width)) / 4) * 4), height: CGFloat((floorf(Float(bounds.height)) / 4) * 4))
let extent = CGRect(x: CGFloat((enhancedImage?.extent.origin.x)!), y: CGFloat((enhancedImage?.extent.origin.y)!), width: CGFloat(bounds.width), height: CGFloat(bounds.height))
let bytesPerPixel: CGFloat = 8
let rowBytes = bytesPerPixel * bounds.width
let totalBytes = rowBytes * bounds.height
let byteBuffer = malloc(Int(totalBytes))
let colorSpace = CGColorSpaceCreateDeviceRGB()
ctx!.render(enhancedImage!, toBitmap: byteBuffer!, rowBytes: Int(rowBytes), bounds: extent, format: kCIFormatRGBA8, colorSpace: colorSpace)
let bitmapContext = CGContext(data: byteBuffer, width: Int(bounds.width), height: Int(bounds.height), bitsPerComponent: Int(bytesPerPixel), bytesPerRow: Int(rowBytes), space: colorSpace, bitmapInfo: CGImageAlphaInfo.noneSkipLast.rawValue)
let imgRef = bitmapContext?.makeImage()
free(byteBuffer)
self.saveCGImageAsJPEGToFilePath(imgRef: imgRef!, filePath: fullPath)
DispatchQueue.main.async(execute: {() -> Void in
completionHandler(fullPath)
self.captureQueue?.resume()
})
self.imageDedectionConfidence = 0.0
}
}
}
所以它需要 AVCaptureStillImageOutput 将其转换为 CIImage 以用于所有需要的用途，然后将其转换为 CGImage 以进行保存。我在翻译中到底做错了什么？还是有更好的方法来做到这一点？
我真的不想问这个问题，但我似乎找不到任何像这样的问题，或者至少找不到任何涉及从AVCaptureStillImageOutput 捕获为CIImage 的问题。
感谢您的帮助！
【问题讨论】：
标签： ios objective-c swift avcaptureoutput