快速创建随机像素图像

Question

我想迅速创建一个随机像素生成器。

我将如何迅速创建类似于以下代码的内容？

用于演示创建随机像素图像的Java程序

import java.io.File; 
import java.io.IOException; 
import java.awt.image.BufferedImage; 
import javax.imageio.ImageIO; 
public class RandomImage 
{ 
    public static void main(String args[])throws IOException 
    { 
        // Image file dimensions 
        int width = 640, height = 320; 

        // Create buffered image object 
        BufferedImage img = null; 
        img = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB); 

        // file object 
        File f = null; 

        // create random values pixel by pixel 
        for (int y = 0; y < height; y++) 
        { 
            for (int x = 0; x < width; x++) 
            { 
                int a = (int)(Math.random()*256); //generating 
                int r = (int)(Math.random()*256); //values 
                int g = (int)(Math.random()*256); //less than 
                int b = (int)(Math.random()*256); //256 

                int p = (a<<24) | (r<<16) | (g<<8) | b; //pixel 

                img.setRGB(x, y, p); 
            } 
        } 

        // write image 
        try
        { 
            f = new File("G:\\Out.jpg"); 
            ImageIO.write(img, "jpg", f); 
        } 
        catch(IOException e) 
        { 
            System.out.println("Error: " + e); 
        } 
    } 
} 

这是我唯一能实现的。从下面的代码，您将知道我绝对是个敏捷的新手。

import Cocoa

class ViewController: NSViewController {

                let height=500
                let width=500
                for y in 0..<height {
                    for x in 0..<width {

                    }
                }



    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }

    override var representedObject: Any? {
        didSet {
        }
    }
}

Answer 1

这是用于macOS的创建NSImage的解决方案：

public struct PixelData {
    var a: UInt8
    var r: UInt8
    var g: UInt8
    var b: UInt8
}

func imageFromARGB32Bitmap(pixels: [PixelData], width: Int, height: Int) -> NSImage? {
    guard width > 0 && height > 0 else { return nil }
    guard pixels.count == width * height else { return nil }

    let rgbColorSpace = CGColorSpaceCreateDeviceRGB()
    let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.premultipliedFirst.rawValue)
    let bitsPerComponent = 8
    let bitsPerPixel = 32

    var data = pixels // Copy to mutable []
    guard let providerRef = CGDataProvider(data: NSData(bytes: &data,
                            length: data.count * MemoryLayout<PixelData>.size)
        )
        else { return nil }

    guard let cgim = CGImage(
        width: width,
        height: height,
        bitsPerComponent: bitsPerComponent,
        bitsPerPixel: bitsPerPixel,
        bytesPerRow: width * MemoryLayout<PixelData>.size,
        space: rgbColorSpace,
        bitmapInfo: bitmapInfo,
        provider: providerRef,
        decode: nil,
        shouldInterpolate: true,
        intent: .defaultIntent
        )
        else { return nil }

    return NSImage(cgImage: cgim, size: NSSize(width: width, height: height))
}

要使用此功能，请创建一个PixelData的数组，然后调用imageFromARGB32Bitmap，并传入pixels，width和height。它会返回一个可选的NSImage，如果创建图像时出现任何错误，则返回nil。

示例用法：

var pixels = [PixelData]()

let height=500
let width=500

for _ in 0..<height {
    for _ in 0..<width {
        pixels.append(PixelData(a: .random(in: 0...255), r: .random(in: 0...255), g: .random(in: 0...255), b: .random(in: 0...255)))
    }
}

let image = imageFromARGB32Bitmap(pixels: pixels, width: width, height: height)

Answer 2

您可以使用下面的func来创建随机的UIImage

    public struct PixelData {
        var a: UInt8
        var r: UInt8
        var g: UInt8
        var b: UInt8
    }

    func createRandomUIImage(width: Int, height: Int) -> UIImage? {
        var pixels = [PixelData]()
        let rgbColorSpace = CGColorSpaceCreateDeviceRGB()
        let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.premultipliedFirst.rawValue)
        let bitsPerComponent = 8
        let bitsPerPixel = 32

        for _ in 0..<width {
            for _ in 0..<height {
                pixels.append(PixelData(a: .random(in: 0...255), r: .random(in: 0...255), g: .random(in: 0...255), b: .random(in: 0...255)))
            }
        }

        guard let providerRef = CGDataProvider(data: NSData(bytes: &pixels,
                                length: pixels.count * MemoryLayout<PixelData>.size)
            )
            else { return nil }

        guard let cgim = CGImage(
            width: width,
            height: height,
            bitsPerComponent: bitsPerComponent,
            bitsPerPixel: bitsPerPixel,
            bytesPerRow: width * MemoryLayout<PixelData>.size,
            space: rgbColorSpace,
            bitmapInfo: bitmapInfo,
            provider: providerRef,
            decode: nil,
            shouldInterpolate: true,
            intent: .defaultIntent
            )
            else { return nil }

        return UIImage(cgImage: cgim)
    }