Kingfisher: Center crop ImageProcessor

Created on 4 Oct 2016 · 9Comments · Source: onevcat/Kingfisher

Issue #320 talks about a crop image processor.

Do you think a center crop image processor fits into the current collection of core processors?

Source

newmanw

Most helpful comment

Cropping image is implemented in #630 now.

onevcat on 26 Mar 2017

❤4

All 9 comments

Sure, it could be a great improvement! Do you have time to implement it? (or I will handle it later since I'm getting quite busy for now)

onevcat on 5 Oct 2016

I can certainly take a crack at it, with a warning that I just started using swift ;)

Do you think it makes more sense as a separate ImageProcessor, or possibly as part of options passed to the current resize processor?

newmanw on 5 Oct 2016

I believe it would be better to be a new one :)

onevcat on 5 Oct 2016

With crop anchor as parameter, and center as its default value.

onevcat on 5 Oct 2016

👍1

I put together a quick centre crop processor that I needed for my app, posting it here for anyone that might need it. I have not implemented the anchor yet, if I do I'll create a pull request. :) (P.S.: The code was found on stack overflow, I just put it in an ImageProcessor)

import Foundation
import Kingfisher

/// Processor for cropping the center of an image
public struct CenterCropImageProcessor: ImageProcessor {
        public let identifier: String

        /// Center point to crop to.
        public var centerPoint: CGFloat = 0.0

        /// Initialize a `CenterCropImageProcessor`
        ///
        /// - parameter centerPoint: The center point to crop to.
        ///
        /// - returns: An initialized `CenterCropImageProcessor`.
        public init(centerPoint: CGFloat? = nil) {
            if let center = centerPoint {
                self.centerPoint = center
            }
            self.identifier = "com.l4grange.CenterCropImageProcessor(\(centerPoint))"
        }

        public func process(item: ImageProcessItem, options: KingfisherOptionsInfo) -> Image? {
            switch item {
            case .image(let image):

                var imageHeight = image.size.height
                var imageWidth = image.size.width

                if imageHeight > imageWidth {
                    imageHeight = imageWidth
                }
                else {
                    imageWidth = imageHeight
                }

                let size = CGSize(width: imageWidth, height: imageHeight)

                let refWidth : CGFloat = CGFloat(image.cgImage!.width)
                let refHeight : CGFloat = CGFloat(image.cgImage!.height)

                let x = (refWidth - size.width) / 2
                let y = (refHeight - size.height) / 2

                let cropRect = CGRect(x: x, y: y, width: size.height, height: size.width)
                if let imageRef = image.cgImage!.cropping(to: cropRect) {
                    return UIImage(cgImage: imageRef, scale: 0, orientation: image.imageOrientation)
                }

                return nil

            case .data(_):
                return (DefaultImageProcessor.default >> self).process(item: item, options: options)
            }
        }
}