swift - 使用 cocoa/osx/swift 更改图像的分辨率和大小(无移动应用程序)

Question

我尝试以编程方式更改图像的大小和分辨率，然后保存该图像。

imageView 中的图像大小正在变化，但是当我查看文件“file3.png”时，它始终具有 640x1142 的原始分辨率。

我用谷歌搜索但找不到解决方案。我尝试重新绘制图像。但也许这是错误的策略。

谢谢

@IBAction func pickOneImageBtn(sender: AnyObject) {


    //load image from path
    pickedImage.image = loadImageFromPath(fileInDocumentsDirectory("Angebote.png"))


    let newSize = NSSize(width: 10, height: 10)


    if let image = pickedImage.image {

        print("found image")


        //cast to CGImage
        var imageRect:CGRect = CGRectMake(0, 0, image.size.width, image.size.height)
        let imageRef = image.CGImageForProposedRect(&imageRect, context: nil, hints: nil)

        if let imageRefExists = imageRef {
            print("Cast to CGImage worked \(imageRefExists)")
        }

        //redraw to NSImage with new size
        let imageWithNewSize = NSImage(CGImage: imageRef!, size: newSize)


        //save on disk
        let imgData: NSData! = imageWithNewSize.TIFFRepresentation!
        let bitmap: NSBitmapImageRep! = NSBitmapImageRep(data: imgData!)
        if let pngCoverImage = bitmap!.representationUsingType(NSBitmapImageFileType.NSPNGFileType, properties: [:]) {
            pngCoverImage.writeToFile("/...correctpath.../imageSourceForResize/file3.png", atomically: false)
            print("saved new image")
        }

       //the size is smaller
       pickedImage.image = imageWithNewSize
    }

}

Answer 1

改变

let imgData: NSData! = pickedImage.image!.TIFFRepresentation!

至

let imgData: NSData! = imageWithNewSize.TIFFRepresentation!