我如何将rgbvalues 0和255的位图数组转换为0和1的2d int数组

本文关键字：数组 转换 int 2d rgbvalues 位图 | 更新日期: 2023-09-27 18:17:44

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
namespace ConvertBitmapToArray
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            Bitmap bitmap = new Bitmap(@"C:'Temp'Gimp Maps'Bitmaps'test1.bmp");
            CreateArray(bitmap);
            File.Create(@"C:'Temp'Gimp Maps'Maps.cs");
        }
        private void CreateArray(Bitmap bmp)
        {
            Rectangle rect = new Rectangle(0, 0, bmp.Width, bmp.Height);
            System.Drawing.Imaging.BitmapData bmpData = bmp.LockBits(rect, System.Drawing.Imaging.ImageLockMode.ReadWrite, bmp.PixelFormat);
            IntPtr ptr = bmpData.Scan0;
            int bytes = Math.Abs(bmpData.Stride) * bmp.Height;
            byte[] rgbValues = new byte[bytes];
            System.Runtime.InteropServices.Marshal.Copy(ptr, rgbValues, 0, bytes);
            System.Runtime.InteropServices.Marshal.Copy(rgbValues, 0, ptr, bytes);
            bmp.UnlockBits(bmpData);
            for (int i = 0; i < rgbValues.Count(); i++)
            {
            }
        }
        private void Form1_Load(object sender, EventArgs e)
        {
        }
    }
}

我有一个黑白位图，大小为8x8或800x800，我得到rgbValues数组。现在在循环中:

for (int i = 0; i < rgbValues.Count(); i++)
{
}

我想创建一个2d的int数组，由0和1组成。例如:

int[,] map = new int[,] 
{
    {0,0,0,0,0,0,0,0,},
    {0,0,0,0,0,0,0,0,},
    {0,0,0,0,0,0,0,0,},
    {1,1,1,1,0,0,0,0,},
    {0,0,0,1,0,0,0,0,},
    {0,0,1,1,0,0,0,0,},
    {0,0,0,0,1,1,1,0,},
    {0,0,0,0,0,0,0,1,},
};

255等于0 0等于1。在int数组的例子中，1是黑色，0是白色。

我试过了:

private void CreateArray(Bitmap bmp)
{
    int[] pix = new int[bmp.Width*bmp.Height];
    int x, y, rgb, val;
    for (y = 0; y < bmp.Height; y++)
    {
        for (x = 0; x < bmp.Width; x++)
        {
            Color c = bmp.GetPixel(x, y);
            rgb = c.ToArgb();
            if (rgb == 0xff000000) // if black
            { 
                val = 0;
            }
            else
                val = 1;
            pix[y * bmp.Width + x] = val;
        }
    }
}

但它不是很好，我不确定颜色c和rgb = c. toargb ();

在if条件下，我得到了绿行:

警告1与积分常数的比较是无用的;该常量在类型'int'

的范围之外。

我怎么能做到这一点与LockBits或与GetPixel ?我想知道使用每种方法有什么不同。

这是我目前所做的:

private void CreateArray(Bitmap bmp)
        {
            int[,] array = new int[,]
            {
            };
            // Lock the bitmap's bits.  
            Rectangle rect = new Rectangle(0, 0, bmp.Width, bmp.Height);
            System.Drawing.Imaging.BitmapData bmpData =
                bmp.LockBits(rect, System.Drawing.Imaging.ImageLockMode.ReadWrite,
                bmp.PixelFormat);
            // Get the address of the first line.
            IntPtr ptr = bmpData.Scan0;
            // Declare an array to hold the bytes of the bitmap. 
            int bytes  = Math.Abs(bmpData.Stride) * bmp.Height;
            byte[] rgbValues = new byte[bytes];

            int x, y, rgb, val;
            for (y = 0; y < bmp.Height; y++)
            {
                for (x = 0; x < bmp.Width; x++)
                {
                    var row = ptr + (y * bmpData.Stride);
                    var pixel = row + x * ; // bpp will be 4 in your case
                    // A bit=0
                    // R bit=1
                    // G bit=2
                    // B bit=3
                    // (depending on your image pixel format)
                    for (var bit = 0; bit < bpp; bit++)
                    {
                        var pixelComponent = pixel[bit];
                    }
                }
            }
        }

我如何将rgbvalues 0和255的位图数组转换为0和1的2d int数组

要以更合乎逻辑的方式循环图像的字节，请将unsafe关键字添加到函数签名(private unsafe void ...)中，并确保通过项目属性启用unsafe代码。

var pt = (byte*)bmpData.Scan0;

现在可以很容易地遍历x和y:

var row = pt + (y * bmpData.Stride);
var pixel = row + x * bpp; // bpp will be 4 in your case
// A bit=0
// R bit=1
// G bit=2
// B bit=3
// (depending on your image pixel format)
for (var bit = 0; bit < bpp; bit++)
{
    var pixelComponent = pixel[bit];
}

如果您真的希望最终结果为二维数组，您应该使用[,]或[][]而不是[](单维数组)

LockBits方法与GetPixel方法之间的巨大差异是性能。GetPixel实际上锁定了比特，检索单个像素并再次解锁比特-这意味着在多次重复执行时性能很差。

编辑

下面是一个完整的代码:

private unsafe void CreateArray(Bitmap bmp)
{
    // Note that is it somewhat a standard
    // to define 2d array access by [y,x] (not [x,y])
    bool[,] bwValues = new bool[bmp.Height, bmp.Width];
    // Lock the bitmap's bits.  
    Rectangle rect = new Rectangle(0, 0, bmp.Width, bmp.Height);
    System.Drawing.Imaging.BitmapData bmpData =
        bmp.LockBits(rect, System.Drawing.Imaging.ImageLockMode.ReadWrite,
        bmp.PixelFormat);
    // Get the address of the first line.
    byte* ptr = (byte*)bmpData.Scan0;
    // Declare an array to hold the bytes of the bitmap. 
    int bytes  = Math.Abs(bmpData.Stride) * bmp.Height;
    for (int y = 0; y < bmp.Height; y++)
    {
        var row = ptr + (y * bmpData.Stride);
        for (int x = 0; x < bmp.Width; x++)
        {
            var pixel = row + x * 4; // ARGB has 4 bytes per pixel
            // A bit=0
            // R bit=1
            // G bit=2
            // B bit=3
            // (depending on your image pixel format)
            // Check if A = R = G = B = 255 (meaning the pixel is white)
            bool isWhite = (pixel[0] == 255 &&
                            pixel[1] == 255 &&
                            pixel[2] == 255 &&
                            pixel[3] == 255);
            // Assume that anything that isn't white is black
            bwValues[y, x] = isWhite;
        }
    }
    // Do whatever you want with vwValues here
}
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