Swift 3的更新

Question

我一直在试图弄清楚如何将一组rgb像素数据转换为Swift中的UIImage。

我将每个像素的rgb数据保存在一个简单的结构中：

public struct PixelData {
   var a: Int
   var r: Int
   var g: Int
   var b: Int
}

我已经开始使用以下功能，但结果图像不正确：

func imageFromARGB32Bitmap(pixels:[PixelData], width: Int, height: Int)-> UIImage {
    let rgbColorSpace = CGColorSpaceCreateDeviceRGB()
    let bitmapInfo:CGBitmapInfo = CGBitmapInfo(CGImageAlphaInfo.PremultipliedFirst.rawValue)
    let bitsPerComponent:Int = 8
    let bitsPerPixel:Int = 32

    assert(pixels.count == Int(width * height))

    var data = pixels // Copy to mutable []
    let providerRef = CGDataProviderCreateWithCFData(
        NSData(bytes: &data, length: data.count * sizeof(PixelData))
    )

    let cgim = CGImageCreate(
        width,
        height,
        bitsPerComponent,
        bitsPerPixel,
        width * Int(sizeof(PixelData)),
        rgbColorSpace,
        bitmapInfo,
        providerRef,
        nil,
        true,
        kCGRenderingIntentDefault
    )
    return UIImage(CGImage: cgim)!
}

有关如何将rgb数组正确转换为UIImage的任何提示或指示？

Answer 1

Swift 3的更新

int T = Integer.parseInt(sc.nextLine());

Answer 2

您唯一的问题是，PixelData结构中的数据类型必须为UInt8。我在Playground中创建了一个测试图像，其中包含以下内容：

public struct PixelData {
    var a: UInt8
    var r: UInt8
    var g: UInt8
    var b: UInt8
}

var pixels = [PixelData]()

let red = PixelData(a: 255, r: 255, g: 0, b: 0)
let green = PixelData(a: 255, r: 0, g: 255, b: 0)
let blue = PixelData(a: 255, r: 0, g: 0, b: 255)

for _ in 1...300 {
    pixels.append(red)
}
for _ in 1...300 {
    pixels.append(green)
}
for _ in 1...300 {
    pixels.append(blue)
}

let image = imageFromARGB32Bitmap(pixels, width: 30, height: 30)

Swift 4的更新：

我更新了imageFromARGB32Bitmap以使用Swift 4.该函数现在返回UIImage?，guard用于在出现任何问题时返回nil。

func imageFromARGB32Bitmap(pixels: [PixelData], width: Int, height: Int) -> UIImage? {
    guard width > 0 && height > 0 else { return nil }
    guard pixels.count == width * height else { return nil }

    let rgbColorSpace = CGColorSpaceCreateDeviceRGB()
    let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.premultipliedFirst.rawValue)
    let bitsPerComponent = 8
    let bitsPerPixel = 32

    var data = pixels // Copy to mutable []
    guard let providerRef = CGDataProvider(data: NSData(bytes: &data,
                            length: data.count * MemoryLayout<PixelData>.size)
        )
        else { return nil }

    guard let cgim = CGImage(
        width: width,
        height: height,
        bitsPerComponent: bitsPerComponent,
        bitsPerPixel: bitsPerPixel,
        bytesPerRow: width * MemoryLayout<PixelData>.size,
        space: rgbColorSpace,
        bitmapInfo: bitmapInfo,
        provider: providerRef,
        decode: nil,
        shouldInterpolate: true,
        intent: .defaultIntent
        )
        else { return nil }

    return UIImage(cgImage: cgim)
}

Swift中的像素阵列到UIImage

2 个答案:

Swift 3的更新