如何使用 C# 的内置方法对图像进行异或? [英] How images can be XOR using C#'s builtin methods?

问题描述

如何使用 C# 内置方法或任何其他图像处理技术对带有 BMP 扩展名的图像进行异或?

How can I XOR images with BMP extension using C# built in methods or any other image processing technique?

我现在正在这样做，但我想要更有效的方法.

I'm now doing this, but I want much more efficient method.

using System;
using System.Drawing;
using System.Drawing.Imaging;

namespace IProcessing
{
/// <summary>
/// Summary description for LogicalOperator.
/// </summary>
public class LogicalOperator
{
    Bitmap bmpimg;
    public LogicalOperator()
    {
        //
        // TODO: Add constructor logic here
        //

    }

    public Bitmap XORing( Bitmap bmp )
    {
        BitmapData bmpData = bmpimg.LockBits( new Rectangle( 0 , 0 , bmpimg.Width , bmpimg.Height ) , ImageLockMode.ReadWrite , PixelFormat.Format24bppRgb );
        BitmapData bmpData2 = bmp.LockBits( new Rectangle( 0 , 0 , bmp.Width , bmp.Height ) , ImageLockMode.ReadWrite , PixelFormat.Format24bppRgb );

        int width = bmpData.Width;
        int height = bmpData.Height;

        if( bmpData2.Width > width )
            width = bmpData2.Width;
        if( bmpData2.Height > height )
            height = bmpData2.Height;

        bmpimg.UnlockBits( bmpData );
        bmp.UnlockBits( bmpData2 );

        Bitmap bit1 = new Bitmap( bmpimg , width , height );
        Bitmap bit2 = new Bitmap( bmp , width , height );

        Bitmap bmpresult = new Bitmap( width , height );

        BitmapData data1 = bit1.LockBits( new Rectangle( 0 , 0 , bit1.Width , bit1.Height ) , ImageLockMode.ReadWrite , PixelFormat.Format24bppRgb );
        BitmapData data2 = bit2.LockBits( new Rectangle( 0 , 0 , bit2.Width , bit2.Height ) , ImageLockMode.ReadWrite , PixelFormat.Format24bppRgb );
        BitmapData data3 = bmpresult.LockBits( new Rectangle( 0 , 0 , bmpresult.Width , bmpresult.Height ) , ImageLockMode.ReadWrite , PixelFormat.Format24bppRgb );

        unsafe
        {
            int remain1 = data1.Stride - data1.Width * 3;
            int remain2 = data2.Stride - data2.Width * 3;
            int remain3 = data3.Stride - data3.Width * 3;

            byte* ptr1 = ( byte* )data1.Scan0;
            byte* ptr2 = ( byte* )data2.Scan0;
            byte* ptr3 = ( byte* )data3.Scan0;

            for( int i = 0 ; i < height ; i ++ )
            {
                for( int j = 0 ; j < width * 3 ; j ++ )
                {
                    ptr3[ 0 ] = ( byte ) ( XOR_Operator( ptr1[ 0 ] , ptr2[ 0 ] ) );
                    ptr1 ++;
                    ptr2 ++;
                    ptr3 ++;
                }

                ptr1 += remain1;
                ptr2 += remain2;
                ptr3 += remain3;
            }


        }

        bit1.UnlockBits( data1 );
        bit2.UnlockBits( data2 );
        bmpresult.UnlockBits( data3 );

        return bmpresult;
    }       

    public byte XOR_Operator( byte a , byte b )
    {

        byte A = ( byte )( 255 - a );
        byte B = ( byte )( 255 - b );

        return ( byte )( ( a & B ) | ( A & b ) );
    }

    public Bitmap XNORing( Bitmap bmp )
    {
 // NANDing of 2 images is done by ANDing 2 images then negating the resultant

        Bitmap orimg = XORing( bmp );

        BitmapData data = orimg.LockBits( new Rectangle( 0 , 0 , orimg.Width , orimg.Height ) , ImageLockMode.ReadWrite , PixelFormat.Format24bppRgb );

        unsafe
        {
            int remain = data.Stride - data.Width * 3;

            byte* ptr = ( byte* )data.Scan0;

            for( int i = 0 ; i < data.Height ; i ++ )
            {
                for( int j = 0 ; j < data.Width * 3 ; j ++ )
                {

                    ptr[ 0 ] = invert( ptr[ 0 ] );
                    ptr ++;
                }

                ptr += remain;
            }

        }

        orimg.UnlockBits( data );

        return orimg;

    }

    public byte invert( byte b )
    {
        return ( byte )( 255 - b );
    }

    public void setImage( Bitmap bmp )
    {
        bmpimg = ( Bitmap )bmp.Clone( );  
    }

    public Bitmap getImage( )
    {
        return ( Bitmap )bmpimg.Clone( );
    }
}
}

推荐答案

使用 C/C++ 来实现这个内循环将大大提高速度.

The big speedup will be from using C/C++ for this inner loop.

其他选择是:

1. 在非托管代码中，如果您使用 GDI 而不是 GDI+ 绘制，您可以使用 SetROP2() 和 R2_XORPEN.这可能比您当前的循环更快，尽管您当前的循环看起来并不太可怕.

1. In the unmanaged code, if you draw with GDI rather than GDI+, you can use SetROP2() with R2_XORPEN. This may be faster than your current loop, although your current loop doesn't look too scary.

如果你的位图只是为了显示在屏幕上，你可以正常显示它，然后用ControlPaint.DrawReversibleLine()

If your bitmap is just for showing on the screen, you could display it normally and then draw over it with ControlPaint.DrawReversibleLine()

这篇关于如何使用 C# 的内置方法对图像进行异或?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！