调整图像周围的白色空间

Question

我试图通过保持纵横比来调整图像大小。但是在调整大小的图像周围存在此空白区域。

extension NSImage { 
func resizeTo(width: CGFloat, height: CGFloat) -> NSImage { 
    let ratioX = width/size.width 
    let ratioY = height/size.height 
    let ratio = ratioX < ratioY ? ratioX : ratioY 
    let newHeight = size.height * ratio 
    let newWidth = size.width * ratio 
    let canvasSize = CGSize(width: width, height: CGFloat(ceil(width/size.width * size.height))) 
    let img = NSImage(size: canvasSize) 
    img.lockFocus() 
    let context = NSGraphicsContext.current() 
    context?.imageInterpolation = .high 
    draw(in: NSRect(origin: .zero, size: NSSize(width: newWidth,height: newHeight)), from: NSRect(origin: .zero, size: size) , operation: .copy, fraction: 1) 
    img.unlockFocus() 
    return img 
    } 
} 

我我做错了什么？

Answer 1

首先要从ratioX和ratioY采摘最小的比例，但后来创建使用ratioX（，大小widthheight * ratioX）的画布。我想说你需要使用newWidth和newHeight创建画布。

let canvasSize = CGSize(width: newWidth, height: newHeight) 

此外，请注意，此脚本将在两个方向上调整大小，即将增加小图像的大小。