如何将AVFoundations captureStillImageAsynchronouslyFromConnection中的TIFF照片保存到iPhone（iOS）上具有EXIF元数据的文件？

有了这个问题，我只想知道我在没有外部库的情况下使用Xcode和iOS的可能性。我已经在探索在另一个应用程序中使用

libtiff

的可能性

问题

几个星期以来，我一直在筛选堆栈溢出，并为我的每一个问题单独找到了有效的解决方案。我有4件事需要做：

我需要RGBA数据，因为它来自摄像机，没有任何压缩

我需要尽可能多的元数据，尤其是EXIF

我需要保存在TIFF格式与其他软件兼容和无损

我需要保存在文件中，而不是照片库中，以防止随意查看

我可以通过使用JPEG获得2和4。 我可以有1，3和4的原始数据（分别为NSData）从相机缓冲区。 我可以用Xcode和iOS拥有我的全部4个先决条件吗？我将放弃，并作为最后手段寻求您的意见

在继续探索这一点的同时，我也被困在了我尝试过的另一条道路上。我还在努力，虽然

下面是我尝试过的建议列表，我自己的代码是从堆栈溢出源中整理出来的，如下所示：

• （这让我希望我能使用JPEG格式，做苹果喜欢做的事情是如此轻松）
• （这将是使用的要点，例如）
• （也适用于kUTTypeTIFF，但不适用于元数据）

解决方案

captureStillImageAsynchronouslyFromConnection

中操作的完整序列：

[[self myAVCaptureStillImageOutput] captureStillImageAsynchronouslyFromConnection:videoConnection completionHandler: ^(CMSampleBufferRef imageSampleBuffer, NSError *error)
 {
     //get all the metadata in the image
     CFDictionaryRef metadata = CMCopyDictionaryOfAttachments(kCFAllocatorDefault, imageSampleBuffer, kCMAttachmentMode_ShouldPropagate);
     // get image reference
     CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(imageSampleBuffer);
     // >>>>>>>>>> lock buffer address
     CVPixelBufferLockBaseAddress(imageBuffer, 0);

     //Get information about the image
     uint8_t *baseAddress = (uint8_t *)CVPixelBufferGetBaseAddress(imageBuffer);
     size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);
     size_t width = CVPixelBufferGetWidth(imageBuffer);
     size_t height = CVPixelBufferGetHeight(imageBuffer);

     // create suitable color space
     CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();

     //Create suitable context (suitable for camera output setting kCVPixelFormatType_32BGRA)
     CGContextRef newContext = CGBitmapContextCreate(baseAddress, width, height, 8, bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);

     // <<<<<<<<<< unlock buffer address
     CVPixelBufferUnlockBaseAddress(imageBuffer, 0);

     // release color space
     CGColorSpaceRelease(colorSpace);

     //Create a CGImageRef from the CVImageBufferRef
     CGImageRef newImage = CGBitmapContextCreateImage(newContext);

     // release context
     CGContextRelease(newContext);

     // create destination and write image with metadata
     CFURLRef url = (__bridge CFURLRef)[NSURL fileURLWithPath:filePath isDirectory:NO];
     CGImageDestinationRef destination = CGImageDestinationCreateWithURL(url, kUTTypeTIFF, 1, NULL);
     CGImageDestinationAddImage(destination, imageRef, metadata);

     // finalize and release destination
     CGImageDestinationFinalize(destination);
     CFRelease(destination);
 }

及

我得到了一个很好的名义上未压缩的图像，格式为名义上的TIFF格式，包含所有元数据。（它在其他系统上镜像，但现在我可以编写EXIF和其他元数据，我相信我也可以对其进行微调）

---

再次感谢他的帮助

既然您已经破解了1、3和4，那么您缺少的唯一障碍似乎就是将数据和元数据一起保存。尝试此操作（假设未处理的数据位于名为

myImageDataSampleBuffer

的

CMSampleBufferRef

中，并且您已经完成了将图形数据放入名为

myImage

的

CGImageRef

中的繁重工作）：

---

这个线程对解决一个非常类似的问题非常有帮助，所以我想我应该提供一个解决方案的Swift 2.0实现，以防有人来看

stillImageOutput?.captureStillImageAsynchronouslyFromConnection(videoConnection, completionHandler: { (imageDataSampleBuffer, error) -> Void in


    // get image meta data (EXIF, etc)
    let metaData: CFDictionaryRef? = CMCopyDictionaryOfAttachments( kCFAllocatorDefault, imageDataSampleBuffer, kCMAttachmentMode_ShouldPropagate )


    // get reference to image
    guard let imageBuffer = CMSampleBufferGetImageBuffer( imageDataSampleBuffer ) else { return }


    // lock the buffer
    CVPixelBufferLockBaseAddress( imageBuffer, 0 )


    // read image properties
    let baseAddress = CVPixelBufferGetBaseAddress( imageBuffer )

    let bytesPerRow = CVPixelBufferGetBytesPerRow( imageBuffer )

    let width = CVPixelBufferGetWidth( imageBuffer )

    let height = CVPixelBufferGetHeight( imageBuffer )


    // color space
    let colorSpace = CGColorSpaceCreateDeviceRGB()


    // context - camera output settings kCVPixelFormatType_32BGRA
    let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.PremultipliedFirst.rawValue).union(.ByteOrder32Little)

    let newContext = CGBitmapContextCreate( baseAddress, width, height, 8, bytesPerRow, colorSpace, bitmapInfo.rawValue )


    //unlock buffer
    CVPixelBufferUnlockBaseAddress( imageBuffer, 0 )

    //Create a CGImageRef from the CVImageBufferRef
    guard let newImage = CGBitmapContextCreateImage( newContext ) else {
        return
    }


    // create tmp file and write image with metadata
    let fileName = String(format: "%@_%@", NSProcessInfo.processInfo().globallyUniqueString, "cap.tiff")
    let fileURL = NSURL(fileURLWithPath: NSTemporaryDirectory()).URLByAppendingPathComponent(fileName)

    if let destination = CGImageDestinationCreateWithURL( fileURL, kUTTypeTIFF, 1, nil) {

        CGImageDestinationAddImage( destination, newImage, metaData )

        let wrote = CGImageDestinationFinalize( destination )

        if !wrote || NSFileManager.defaultManager().fileExistsAtPath(fileURL.URLString) {

            return

        }

    }

}

p、 要使其工作，您必须如下配置图像缓冲区：

    stillImageOutput = AVCaptureStillImageOutput()

    stillImageOutput?.outputSettings = [ kCVPixelBufferPixelFormatTypeKey: Int(kCVPixelFormatType_32BGRA) ]

---

非常感谢你！我会尽快尝试：）我不会忘记的。我还没有时间尝试，因为我现在正忙于我的软件中的另一个问题。答应我！请再看一看。如何读回这些文件（需要在

UICollectionView

中显示缩略图）？

CFDictionaryRef metadata = CMCopyDictionaryOfAttachments(kCFAllocatorDefault,
  myImageDataSampleBuffer,
  kCMAttachmentMode_ShouldPropagate);
NSFileManager* fm = [[NSFileManager alloc] init];
NSURL* pathUrl = [fm URLForDirectory:saveDir
  inDomain:NSUserDomainMask
  appropriateForURL:nil
  create:YES
  error:nil];
NSURL* saveUrl = [pathUrl URLByAppendingPathComponent:@"myfilename.tif"];
CGImageDestinationRef destination = CGImageDestinationCreateWithURL((__bridge CFURLRef)saveUrl,
  (CFStringRef)@"public.tiff", 1, NULL);
CGImageDestinationAddImage(destination, myImage, metadata);
CGImageDestinationFinalize(destination);
CFRelease(destination);

stillImageOutput?.captureStillImageAsynchronouslyFromConnection(videoConnection, completionHandler: { (imageDataSampleBuffer, error) -> Void in


    // get image meta data (EXIF, etc)
    let metaData: CFDictionaryRef? = CMCopyDictionaryOfAttachments( kCFAllocatorDefault, imageDataSampleBuffer, kCMAttachmentMode_ShouldPropagate )


    // get reference to image
    guard let imageBuffer = CMSampleBufferGetImageBuffer( imageDataSampleBuffer ) else { return }


    // lock the buffer
    CVPixelBufferLockBaseAddress( imageBuffer, 0 )


    // read image properties
    let baseAddress = CVPixelBufferGetBaseAddress( imageBuffer )

    let bytesPerRow = CVPixelBufferGetBytesPerRow( imageBuffer )

    let width = CVPixelBufferGetWidth( imageBuffer )

    let height = CVPixelBufferGetHeight( imageBuffer )


    // color space
    let colorSpace = CGColorSpaceCreateDeviceRGB()


    // context - camera output settings kCVPixelFormatType_32BGRA
    let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.PremultipliedFirst.rawValue).union(.ByteOrder32Little)

    let newContext = CGBitmapContextCreate( baseAddress, width, height, 8, bytesPerRow, colorSpace, bitmapInfo.rawValue )


    //unlock buffer
    CVPixelBufferUnlockBaseAddress( imageBuffer, 0 )

    //Create a CGImageRef from the CVImageBufferRef
    guard let newImage = CGBitmapContextCreateImage( newContext ) else {
        return
    }


    // create tmp file and write image with metadata
    let fileName = String(format: "%@_%@", NSProcessInfo.processInfo().globallyUniqueString, "cap.tiff")
    let fileURL = NSURL(fileURLWithPath: NSTemporaryDirectory()).URLByAppendingPathComponent(fileName)

    if let destination = CGImageDestinationCreateWithURL( fileURL, kUTTypeTIFF, 1, nil) {

        CGImageDestinationAddImage( destination, newImage, metaData )

        let wrote = CGImageDestinationFinalize( destination )

        if !wrote || NSFileManager.defaultManager().fileExistsAtPath(fileURL.URLString) {

            return

        }

    }

}

    stillImageOutput = AVCaptureStillImageOutput()

    stillImageOutput?.outputSettings = [ kCVPixelBufferPixelFormatTypeKey: Int(kCVPixelFormatType_32BGRA) ]