UIImage 崩溃上的 Swift 模糊扩展答案

【问题标题】：Swift blur extension on UIImage crashesUIImage 崩溃上的 Swift 模糊扩展
【发布时间】：2016-05-01 21:14:56
【问题描述】：

我已经为 UIImage 编写了一个扩展，并为上下文获取 nil。知道可能是什么问题吗？

public func blur(size: Float) -> UIImage! {

    let boxSize = size - (size % 2) + 1
    let image = self.CGImage
    let inProvider = CGImageGetDataProvider(image)

    let height = vImagePixelCount(CGImageGetHeight(image))
    let width = vImagePixelCount(CGImageGetWidth(image))
    let rowBytes = CGImageGetBytesPerRow(image)

    let inBitmapData = CGDataProviderCopyData(inProvider)
    let inData = UnsafeMutablePointer<Void>(CFDataGetBytePtr(inBitmapData))
    var inBuffer = vImage_Buffer(data: inData, height: height, width: width, rowBytes: rowBytes)

    let outData = malloc(CGImageGetBytesPerRow(image) * CGImageGetHeight(image))
    var outBuffer = vImage_Buffer(data: outData, height: height, width: width, rowBytes: rowBytes)

    let _ = vImageBoxConvolve_ARGB8888(&inBuffer, &outBuffer, nil, 0, 0, UInt32(boxSize), UInt32(boxSize), nil, vImage_Flags(kvImageEdgeExtend))

    let colorSpace = CGColorSpaceCreateDeviceRGB()
    let context = CGBitmapContextCreate(outBuffer.data, Int(outBuffer.width), Int(outBuffer.height), 8, outBuffer.rowBytes, colorSpace, CGImageGetBitmapInfo(image).rawValue)
    let imageRef = CGBitmapContextCreateImage(context)!
    let bluredImage = UIImage(CGImage: imageRef)

    free(outData)

    return bluredImage
}

【问题讨论】：

我无法重现您的问题，此代码对我来说没问题。

标签： swift uiimage uikit

【解决方案1】：

问题是直接在 CGImage 而不是 UIImage 上进行模糊处理：

extension UIImage {
    class func blurEffect(cgImage: CGImageRef) -> UIImage! {
        return UIImage(CGImage: cgImage)
    }

    func blurEffect(boxSize: CGFloat) -> UIImage! {
        return UIImage(CGImage: bluredCGImage(boxSize))
    }

    func bluredCGImage(boxSize: CGFloat) -> CGImageRef! {
        return CGImage!.blurEffect(boxSize)
    }
}

extension CGImage {
    func blurEffect(boxSize: CGFloat) -> CGImageRef! {

        let boxSize = boxSize - (boxSize % 2) + 1

        let inProvider = CGImageGetDataProvider(self)

        let height = vImagePixelCount(CGImageGetHeight(self))
        let width = vImagePixelCount(CGImageGetWidth(self))
        let rowBytes = CGImageGetBytesPerRow(self)

        let inBitmapData = CGDataProviderCopyData(inProvider)
        let inData = UnsafeMutablePointer<Void>(CFDataGetBytePtr(inBitmapData))
        var inBuffer = vImage_Buffer(data: inData, height: height, width: width, rowBytes: rowBytes)

        let outData = malloc(CGImageGetBytesPerRow(self) * CGImageGetHeight(self))
        var outBuffer = vImage_Buffer(data: outData, height: height, width: width, rowBytes: rowBytes)

        vImageBoxConvolve_ARGB8888(&inBuffer, &outBuffer, nil, 0, 0, UInt32(boxSize), UInt32(boxSize), nil, vImage_Flags(kvImageEdgeExtend))

        let colorSpace = CGColorSpaceCreateDeviceRGB()
        let context = CGBitmapContextCreate(outBuffer.data, Int(outBuffer.width), Int(outBuffer.height), 8, outBuffer.rowBytes, colorSpace, CGImageGetBitmapInfo(self).rawValue)
        let imageRef = CGBitmapContextCreateImage(context)

        free(outData)

        return imageRef
    }
}

【讨论】：