使用UIImage ()将着色的CGColorSpaceCreateDeviceGray转换为灰度
使用UIImage ()将着色的CGColorSpaceCreateDeviceGray转换为灰度
提问于 2017-03-27 07:29:44
我正在尝试将UIImage转换为GrayScale。它所造成的只是一个完全黑色的形象。
func convertToGrayScale2(image: UIImage) -> UIImage {
let imageRect:CGRect = CGRect(x:0, y:0, width:image.size.width, height: image.size.height)
let colorSpace = CGColorSpaceCreateDeviceGray()
let width = image.size.width
let height = image.size.height
let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.none.rawValue)
let context = CGContext(data: nil, width: Int(width), height: Int(height), bitsPerComponent: 8, bytesPerRow: 0, space: colorSpace, bitmapInfo: bitmapInfo.rawValue)
let imageRef = context!.makeImage()
context?.draw(imageRef!, in: imageRect)
let newImage = UIImage(cgImage: imageRef!)
return newImage
}密码有什么问题吗？我需要现有代码的帮助。它以前起作用了。突然不起作用了。
回答 3
Stack Overflow用户
回答已采纳
发布于 2017-03-27 10:04:34
func convertToGrayScale(image: UIImage) -> UIImage {
let imageRect:CGRect = CGRect(x:0, y:0, width:image.size.width, height: image.size.height)
let colorSpace = CGColorSpaceCreateDeviceGray()
let width = image.size.width
let height = image.size.height
let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.none.rawValue)
let context = CGContext(data: nil, width: Int(width), height: Int(height), bitsPerComponent: 8, bytesPerRow: 0, space: colorSpace, bitmapInfo: bitmapInfo.rawValue)
//have to draw before create image
context?.draw(image.cgImage!, in: imageRect)
let imageRef = context!.makeImage()
let newImage = UIImage(cgImage: imageRef!)
return newImage
}Stack Overflow用户
发布于 2017-03-27 08:31:06
您可以使用此函数来代替：
func convertImageToDifferentColorScale(with originalImage:UIImage, imageStyle:String) -> UIImage {
let currentFilter = CIFilter(name: imageStyle)
currentFilter!.setValue(CIImage(image: originalImage), forKey: kCIInputImageKey)
let output = currentFilter!.outputImage
let context = CIContext(options: nil)
let cgimg = context.createCGImage(output!,from: output!.extent)
let processedImage = UIImage(cgImage: cgimg!)
return processedImage
}下面是您如何使用的示例：
let newImage = convertImageToDifferentColorScale(with: UIImage(named: "0318_1")!, imageStyle: "CIPhotoEffectNoir")
testingImageView.image = newImage在imageStyle部分中，有几种不同的样式，如下所示：
CIColorCrossPolynomial CIColorCube CIColorCubeWithColorSpace CIColorInvert CIColorMap CIColorMonochrome CIColorPosterize CIFalseColor CIMaskToAlpha CIMaximumComponent CIMinimumComponent CIPhotoEffectChrome CIPhotoEffectFade CIPhotoEffectInstant CIPhotoEffectMono CIPhotoEffectNoir
'CIPhotoEffectNoir'是一个可以给你gray scale的选择。
Stack Overflow用户
发布于 2017-03-27 07:38:46
另一种可能的选择可能是使用CoreImage过滤器。请参阅以下SO Post及其Accepted Answer。希望能帮上忙。编码愉快！
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/43040333
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