快速：对于HEIC图像，PHAssetChangeRequest失败

Question

快速：对于HEIC图像，PHAssetChangeRequest失败

5

我希望对来自相册（由iPhone相机拍摄）的图像进行编辑，例如进行JPEG压缩，但当输入的图像是HEIC格式时失败，但对于JPEG图像可以正常工作。

我通过UIImagePickerController方法在PHAsset对象中检索图像：

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        if let asset = info[UIImagePickerController.InfoKey.phAsset] as? PHAsset {
            self.asset = asset
        }

        //...
    }

该函数编辑所选图像：

func editImage() {
if let _asset = self.asset {
        _asset.requestContentEditingInput(with: nil, completionHandler: { (contentEditingInput, info) in
            let fullURL: URL?
            fullURL = contentEditingInput!.fullSizeImageURL

            let output = PHContentEditingOutput(contentEditingInput:
                contentEditingInput!)
            let archivedData = try? NSKeyedArchiver.archivedData(withRootObject: "HEICEditor", requiringSecureCoding: false)
            let adjustmentData =
                PHAdjustmentData(formatIdentifier:
                    "HEICEditor.App",
                                 formatVersion: "1.0",
                                 data: archivedData!)

            output.adjustmentData = adjustmentData
            let imageData = UIImage.init(contentsOfFile: fullURL!.path)?.jpegData(compressionQuality: 0.5)

            do {
                try imageData!.write(to: output.renderedContentURL, options: .atomic)
            } catch let error {
                print("error writing data:\(error)")
            }

            PHPhotoLibrary.shared().performChanges({
                let request = PHAssetChangeRequest(for: _asset)
                request.contentEditingOutput = output

            }, completionHandler: { (result, error) in
               print("error writing data:\(error)")

            })

        })

    }
}

这个项目提供了一个样例 HEIC 图片，可以在以下链接中找到：https://github.com/maysamsh/Swift-Playground-EditHEIC

注意1：通过查看EXIF信息，你可以判断一张图片是否为HEIC格式。或者，选择一张图片并点击“编辑图片”按钮，你可以在预览图像的顶部看到完整名称。
注意2：由于某些原因，在将HEIC图片从iPhone发送到Mac并再次发送回iPhone时，它可以在新副本上正常工作，仍然是HEIC格式，并保留原始图像方向。

- Maysam

1个回答

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- Maysam · Accepted Answer

下面是操作步骤：创建一个CGImageDestination，将输出写入.renderedContentURL，执行the PHAssetChangeRequest()：

func editImage() {
    if let _asset = self.asset {
        let options = PHContentEditingInputRequestOptions()
        options.canHandleAdjustmentData = {(adjustmeta: PHAdjustmentData)
            -> Bool in
            return true
        }
        _asset.requestContentEditingInput(with: options, completionHandler: { (contentEditingInput, info) in
            let fullURL: URL?
            fullURL = contentEditingInput!.fullSizeImageURL
            let output = PHContentEditingOutput(contentEditingInput:
                contentEditingInput!)
            let archivedData = try? NSKeyedArchiver.archivedData(withRootObject: "HEICEditor", requiringSecureCoding: false)
            let adjustmentData =
                PHAdjustmentData(formatIdentifier:
                    "HEICEditor.App",
                                 formatVersion: "1.0",
                                 data: archivedData!)


            let orientation = contentEditingInput?.fullSizeImageOrientation
            let outputURL = output.renderedContentURL
            let cgImage = {
                () -> CGImage in
                let image = UIImage.init(contentsOfFile: fullURL!.path)!
                let imageData = image.jpegData(compressionQuality: 1)
                let ciImage = CIImage(data: imageData!)!.oriented(forExifOrientation: orientation!)

                return CIContext(options: nil).createCGImage(ciImage, from: ciImage.extent)!
            }()

            let cgImageDestination = CGImageDestinationCreateWithURL(outputURL as CFURL, kUTTypeJPEG, 1, nil)!
            CGImageDestinationAddImage(cgImageDestination, cgImage, [
                kCGImageDestinationLossyCompressionQuality as String:0.7
                ] as CFDictionary)
            CGImageDestinationFinalize(cgImageDestination)


            output.adjustmentData = adjustmentData
            self.infoLabel.text = "fullSizeImageURL: \(fullURL?.lastPathComponent ?? "N/A")\n" +
            "renderedContentURL: \(output.renderedContentURL.lastPathComponent)"

            PHPhotoLibrary.shared().performChanges({
                let request = PHAssetChangeRequest(for: _asset)
                request.contentEditingOutput = output
            }, completionHandler: { (result, error) in
                print("result: \(result), error: \(String(describing: error))")
            })

        })

    }
}