swift-playground - CIConstantColorGenerator CIFilter 在 Playground 中使用 Swift 2.0 失败并出现错误

Question

我尝试使用以下代码行创建滤色器

let parameters = [kCIInputColorKey: CIColor(string: "0.5 0.7 0.3 1.0")]
let colorFilter = CIFilter(name: "CIConstantColorGenerator",    withInputParameters: parameters)
colorFilter?.outputImage

但是调试控制台输出滚动信息

 <Error>: CGImageProviderCreate: invalid image provider size: 1.79769e+308 x 1.79769e+308.
<Error>: CGImageCreate: invalid image width.
<Error>: ImageIO: CGImageDestinationFinalize image destination must have at least one image
CGImageDestinationFinalize failed for output type 'public.tiff'

谢谢，加:我尝试在 Swift 项目中编写此代码，它工作正常，但在 Playground 上工作时，只是显示此错误

Answer 1

只需尝试澄清您想要获得的输出图像的大小: colorFilter?.outputImage?.imageByCroppingToRect(CGRectMake(0, 0, 200, 200))