Q:

Swift core image apply sharpen to image without CIFilter

in core image we can use some filters and adding this filters to sharpen but when I want to apply only sharpen to image we need a filter. How can I use this without using CIFilter.
Here is the code sample for apply sharpen with CIFilter:
    let filter = CIFilter(name: "CIPhotoEffectChrome")
    filter.setValue(beginImage, forKey: kCIInputImageKey)
    filter.setValue(1, forKey: kCICategorySharpen)
    let outputImage = filter.outputImage

A:

I'm afraid your code does not really sharpen the input. It's just "applying a "Chrome" style effect to an image" (from the docs). The CIPhotoEffectChrome filter does not have a parameter for sharpening the input.
You rather need to pick one of the filters from the CICategorySharpen, e.g.:
let filter = CIFilter(name: "CIUnsharpMask")
filter.setValue(beginImage, forKey: kCIInputImageKey)
filter.setValue(2.0, forKey: "inputIntensity")
filter.setValue(1.0, forKey: "inputRadius")
let outputImage = filter.outputImage

But why don't you want to use Core Image? It should be the best tool for the job.

