图像阵列中的快速分割
图像阵列中的快速分割
提问于 2017-03-24 19:56:05
我试图把一个图像分割出来(在一个矩阵中)，创建16个图像。我用的是斯威夫特2.1。下面是代码：
let cellSize = Int(originalImage.size.height) / 4
for i in 0...4 {
for p in 0...4 {
let tmpImgRef: CGImage = originalImage.CGImage!
let rect: CGImage = CGImageCreateWithImageInRect(tmpImgRef, CGRectMake(CGFloat(i * cellSize), CGFloat(p * cellSize), CGFloat(cellSize), CGFloat(cellSize)))!
gameCells.append(cell)
}
}这是可行的，但返回的图像只是原始图像的一部分。我一直在搜索，我知道这是因为当我创建一个CGImage时，它的大小与UIImage不同，但我不知道如何修复它。如果我能够使变量cellSize与CGImage的高度而不是UIImage的高度相对应，我想我会修复它，但不能得到CGImage的高度。
谢谢你的帮助！
Stack Overflow用户
发布于 2017-03-24 20:55:39
您可以将图像分割为垂直和水平两部分，并根据需要将结果拆分：
extension UIImage {
var topHalf: UIImage? {
guard let cgImage = cgImage, let image = cgImage.cropping(to: CGRect(origin: .zero, size: CGSize(width: size.width, height: size.height/2))) else { return nil }
return UIImage(cgImage: image, scale: scale, orientation: imageOrientation)
}
var bottomHalf: UIImage? {
guard let cgImage = cgImage, let image = cgImage.cropping(to: CGRect(origin: CGPoint(x: 0, y: CGFloat(Int(size.height)-Int(size.height/2))), size: CGSize(width: size.width, height: CGFloat(Int(size.height) - Int(size.height/2))))) else { return nil }
return UIImage(cgImage: image, scale: scale, orientation: imageOrientation)
}
var leftHalf: UIImage? {
guard let cgImage = cgImage, let image = cgImage.cropping(to: CGRect(origin: .zero, size: CGSize(width: size.width/2, height: size.height))) else { return nil }
return UIImage(cgImage: image, scale: scale, orientation: imageOrientation)
}
var rightHalf: UIImage? {
guard let cgImage = cgImage, let image = cgImage.cropping(to: CGRect(origin: CGPoint(x: CGFloat(Int(size.width)-Int((size.width/2))), y: 0), size: CGSize(width: CGFloat(Int(size.width)-Int((size.width/2))), height: size.height)))
else { return nil }
return UIImage(cgImage: image, scale: scale, orientation: imageOrientation)
}
var splitedInFourParts: [UIImage] {
guard case let topHalf = topHalf,
case let bottomHalf = bottomHalf,
let topLeft = topHalf?.leftHalf,
let topRight = topHalf?.rightHalf,
let bottomLeft = bottomHalf?.leftHalf,
let bottomRight = bottomHalf?.rightHalf else{ return [] }
return [topLeft, topRight, bottomLeft, bottomRight]
}
var splitedInSixteenParts: [UIImage] {
var array = splitedInFourParts.flatMap({$0.splitedInFourParts})
// if you need it in reading order you need to swap some image positions
swap(&array[2], &array[4])
swap(&array[3], &array[5])
swap(&array[10], &array[12])
swap(&array[11], &array[13])
return array
}
}将图像按列和行拆分：
extension UIImage {
func matrix(_ rows: Int, _ columns: Int) -> [UIImage] {
let y = (size.height / CGFloat(rows)).rounded()
let x = (size.width / CGFloat(columns)).rounded()
var images: [UIImage] = []
images.reserveCapacity(rows * columns)
guard let cgImage = cgImage else { return [] }
(0..<rows).forEach { row in
(0..<columns).forEach { column in
var width = Int(x)
var height = Int(y)
if row == rows-1 && size.height.truncatingRemainder(dividingBy: CGFloat(rows)) != 0 {
height = Int(size.height - size.height / CGFloat(rows) * (CGFloat(rows)-1))
}
if column == columns-1 && size.width.truncatingRemainder(dividingBy: CGFloat(columns)) != 0 {
width = Int(size.width - (size.width / CGFloat(columns) * (CGFloat(columns)-1)))
}
if let image = cgImage.cropping(to: CGRect(origin: CGPoint(x: column * Int(x), y: row * Int(x)), size: CGSize(width: width, height: height))) {
images.append(UIImage(cgImage: image, scale: scale, orientation: imageOrientation))
}
}
}
return images
}
}let myPicture = UIImage(data: try! Data(contentsOf: URL(string:"https://i.stack.imgur.com/Xs4RX.jpg")!))!
let images = myPicture.matrix(4, 4)
images.count // 16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/43008098
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