C#圖像處理(各類旋轉、改變大小、柔化、銳化、霧化、底片、浮雕、黑白、濾鏡效果)

時間 2019-11-16

原文原文鏈接

1、各類旋轉、改變大小算法

注意：先要添加畫圖相關的using引用。c#

//向右旋轉圖像90°代碼以下:
private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{windows

Graphics g = e.Graphics;
Bitmap bmp = new Bitmap("rama.jpg");//加載圖像
g.FillRectangle(Brushes.White, this.ClientRectangle);//填充窗體背景爲白色
Point[] destinationPoints = {
new Point(100, 0), // destination for upper-left point of original
new Point(100, 100),// destination for upper-right point of original
new Point(0, 0)}; // destination for lower-left point of original
g.DrawImage(bmp, destinationPoints);數組

}dom

//旋轉圖像180°代碼以下:
private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{編輯器

Graphics g = e.Graphics;
Bitmap bmp = new Bitmap("rama.jpg");
g.FillRectangle(Brushes.White, this.ClientRectangle);
Point[] destinationPoints = {
new Point(0, 100), // destination for upper-left point of original
new Point(100, 100),// destination for upper-right point of original
new Point(0, 0)}; // destination for lower-left point of original
g.DrawImage(bmp, destinationPoints);ide

}函數

//圖像切變代碼:
private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{工具

Graphics g = e.Graphics;
Bitmap bmp = new Bitmap("rama.jpg");
g.FillRectangle(Brushes.White, this.ClientRectangle);
Point[] destinationPoints = {
new Point(0, 0), // destination for upper-left point of original
new Point(100, 0), // destination for upper-right point of original
new Point(50, 100)};// destination for lower-left point of original
g.DrawImage(bmp, destinationPoints);oop

}

//圖像截取:
private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{

Graphics g = e.Graphics;
Bitmap bmp = new Bitmap("rama.jpg");
g.FillRectangle(Brushes.White, this.ClientRectangle);
Rectangle sr = new Rectangle(80, 60, 400, 400);//要截取的矩形區域
Rectangle dr = new Rectangle(0, 0, 200, 200);//要顯示到Form的矩形區域
g.DrawImage(bmp, dr, sr, GraphicsUnit.Pixel);

}

//改變圖像大小:
private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{

Graphics g = e.Graphics;
Bitmap bmp = new Bitmap("rama.jpg");
g.FillRectangle(Brushes.White, this.ClientRectangle);
int width = bmp.Width;
int height = bmp.Height;
// 改變圖像大小使用低質量的模式
g.InterpolationMode = InterpolationMode.NearestNeighbor;
g.DrawImage(bmp, new Rectangle(10, 10, 120, 120), // source rectangle

new Rectangle(0, 0, width, height), // destination rectangle
GraphicsUnit.Pixel);
// 使用高質量模式
//g.CompositingQuality = CompositingQuality.HighSpeed;
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.DrawImage(
bmp,
new Rectangle(130, 10, 120, 120),
new Rectangle(0, 0, width, height),
GraphicsUnit.Pixel);

}

//設置圖像的分辯率:
private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{

Graphics g = e.Graphics;
Bitmap bmp = new Bitmap("rama.jpg");
g.FillRectangle(Brushes.White, this.ClientRectangle);
bmp.SetResolution(300f, 300f);
g.DrawImage(bmp, 0, 0);
bmp.SetResolution(1200f, 1200f);
g.DrawImage(bmp, 180, 0);

}

//用GDI+畫圖
private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{

Graphics gForm = e.Graphics;
gForm.FillRectangle(Brushes.White, this.ClientRectangle);
for (int i = 1; i <= 7; ++i)
{

//在窗體上面畫出橙色的矩形

Rectangle r = new Rectangle(i*40-15, 0, 15,
this.ClientRectangle.Height);
gForm.FillRectangle(Brushes.Orange, r);

}

//在內存中建立一個Bitmap並設置CompositingMode
Bitmap bmp = new Bitmap(260, 260,

System.Drawing.Imaging.PixelFormat.Format32bppArgb);
Graphics gBmp = Graphics.FromImage(bmp);
gBmp.CompositingMode = System.Drawing.Drawing2D.CompositingMode.SourceCopy;
// 建立一個帶有Alpha的紅色區域
// 並將其畫在內存的位圖裏面
Color red = Color.FromArgb(0x60, 0xff, 0, 0);
Brush redBrush = new SolidBrush(red);
gBmp.FillEllipse(redBrush, 70, 70, 160, 160);
// 建立一個帶有Alpha的綠色區域
Color green = Color.FromArgb(0x40, 0, 0xff, 0);
Brush greenBrush = new SolidBrush(green);
gBmp.FillRectangle(greenBrush, 10, 10, 140, 140);
//在窗體上面畫出位圖 now draw the bitmap on our window
gForm.DrawImage(bmp, 20, 20, bmp.Width, bmp.Height);
// 清理資源
bmp.Dispose();
gBmp.Dispose();
redBrush.Dispose();
greenBrush.Dispose();

}

//在窗體上面繪圖並顯示圖像
private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{

Graphics g = e.Graphics;
Pen blackPen = new Pen(Color.Black, 1);

if (ClientRectangle.Height / 10 > 0)

{

for (int y = 0; y < ClientRectangle.Height; y += ClientRectangle.Height / 10)

{

g.DrawLine(blackPen, new Point(0, 0), new Point(ClientRectangle.Width, y));

}

blackPen.Dispose();

}

C# 使用Bitmap類進行圖片裁剪

在Mapwin（手機遊戲地圖編輯器）生成的地圖txt文件中添加本身須要處理的數據後轉換成可在手機（Ophone）開發環境中使用的字節流地圖文件的小工具，其中就涉及到圖片的裁剪和生成了。有如下幾種方式。

方法一：拷貝像素。

固然這種方法是最笨的，效率也就低了些。

在Bitmap類中咱們能夠看到這樣兩個方法：GetPixel（int x, int y）和SetPixel（int x, int y, Color color）方法。從字面的含以上就知道前者是獲取圖像某點像素值，是用Color對象返回的；後者是將已知像素描畫到制定的位置。

下面就來作個實例檢驗下：

1.首先建立一個Windows Form窗體程序，往該窗體上拖放7個PictureBox控件，第一個用於放置並顯示原始的大圖片，其後6個用於放置並顯示裁剪後新生成的6個小圖；

2.放置原始大圖的PictureBox控件name屬性命名爲pictureBoxBmpRes，其後pictureBox1到pictureBox6依次命名，並放置在合適的位置；

3.雙擊Form窗體，而後在Form1_Load事件中加入下面的代碼便可。

//導入圖像資源

Bitmap bmpRes = null;

String strPath = Application.ExecutablePath;

try{

int nEndIndex = strPath.LastIndexOf('//');

strPath = strPath.Substring(0,nEndIndex) + "//Bmp//BmpResMM.bmp";

bmpRes = new Bitmap(strPath);

//窗體上顯示加載圖片

pictureBoxBmpRes.Width = bmpRes.Width;

pictureBoxBmpRes.Height = bmpRes.Height;

pictureBoxBmpRes.Image = bmpRes;

}

catch(Exception ex)

{

System.Windows.Forms.MessageBox.Show("圖片資源加載失敗！/r/n" + ex.ToString());

}

//裁剪圖片(裁成2行3列的6張圖片)

int nYClipNum = 2, nXClipNum = 3;

Bitmap[] bmpaClipBmpArr = new Bitmap[nYClipNum * nXClipNum];

for (int nYClipNumIndex = 0; nYClipNumIndex < nYClipNum; nYClipNumIndex++)

{

for (int nXClipNumIndex = 0; nXClipNumIndex < nXClipNum; nXClipNumIndex++)

{

int nClipWidth = bmpRes.Width / nXClipNum;

int nClipHight = bmpRes.Height / nYClipNum;

int nBmpIndex = nXClipNumIndex + nYClipNumIndex * nYClipNum + (nYClipNumIndex > 0?1:0);

bmpaClipBmpArr[nBmpIndex] = new Bitmap(nClipWidth, nClipHight);

for(int nY = 0; nY < nClipHight; nY++)

{

for(int nX = 0; nX < nClipWidth; nX++)

{

int nClipX = nX + nClipWidth * nXClipNumIndex;

int nClipY = nY + nClipHight * nYClipNumIndex;

Color cClipPixel = bmpRes.GetPixel(nClipX, nClipY);

bmpaClipBmpArr[nBmpIndex].SetPixel(nX, nY, cClipPixel);

}

PictureBox[] picbShow = new PictureBox[nYClipNum * nXClipNum];

picbShow[0] = pictureBox1;

picbShow[1] = pictureBox2;

picbShow[2] = pictureBox3;

picbShow[3] = pictureBox4;

picbShow[4] = pictureBox5;

picbShow[5] = pictureBox6;

for (int nLoop = 0; nLoop < nYClipNum * nXClipNum; nLoop++)

{

picbShow[nLoop].Width = bmpRes.Width / nXClipNum;

picbShow[nLoop].Height = bmpRes.Height / nYClipNum;

picbShow[nLoop].Image = bmpaClipBmpArr[nLoop];

}

如今看看那些地方須要注意的了。其中

int nBmpIndex =

nXClipNumIndex + nYClipNumIndex * nYClipNum + (nYClipNumIndex > 0?1:0);

這句定義了存儲裁剪圖片對象在數組中的索引，須要注意的就是後面的(nYClipNumIndex > 0?1:0)——由於只有當裁剪的對象處於第一行之外的行時須要將索引加1；

另外，由於這種方法的效率不高，程序運行起來仍是頓了下。若是有興趣的話，能夠將以上的代碼放到一個按鈕Click事件函數中，當單擊該按鈕時就能夠感受到了。

方法二：運用Clone函數局部複製。

一樣在Bitmap中能夠找到Clone（）方法，該方法有三個重載方法。Clone（），Clone（Rectangle， PixelFormat）和Clone（RectangleF， PixelFormat）。第一個方法將建立並返回一個精確的實例對象，後兩個就是咱們這裏須要用的局部裁剪了（其實後兩個方法本人以爲用法上差很少）。

將上面的程序稍稍改進下——將裁剪的處理放到一個按鈕事件函數中，而後再託一個按鈕好窗體上，最後將下面的代碼複製到該按鈕的事件函數中。

for (int nYClipNumIndex = 0; nYClipNumIndex < nYClipNum; nYClipNumIndex++)

{

for (int nXClipNumIndex = 0; nXClipNumIndex < nXClipNum; nXClipNumIndex++)

{

int nClipWidth = bmpRes.Width / nXClipNum;

int nClipHight = bmpRes.Height / nYClipNum;

int nBmpIndex =

nXClipNumIndex + nYClipNumIndex * nYClipNum + (nYClipNumIndex > 0 ? 1 : 0);

Rectangle rClipRect = new Rectangle(nClipWidth * nXClipNumIndex,

nClipHight * nYClipNumIndex,

nClipWidth,

nClipHight);

bmpaClipBmpArr[nBmpIndex] = bmpRes.Clone(rClipRect, bmpRes.PixelFormat);

}

運行程序，單擊按鈕檢驗下，發現速度明顯快可不少。

其實這種方法較第一中方法不一樣的地方僅只是變換了for循環中的拷貝部分的處理，

Rectangle rClipRect = new Rectangle(nClipWidth * nXClipNumIndex,

nClipHight * nYClipNumIndex,

nClipWidth,

nClipHight);

bmpaClipBmpArr[nBmpIndex] = bmpRes.Clone(rClipRect, bmpRes.PixelFormat);

一. 底片效果
原理: GetPixel方法得到每一點像素的值, 而後再使用SetPixel方法將取反後的顏色值設置到對應的點.
效果圖:

代碼實現:

          private void button1_Click(object sender, EventArgs e)
        {
            //以底片效果顯示圖像
            try
            {
                int Height = this.pictureBox1.Image.Height;
                int Width = this.pictureBox1.Image.Width;
                Bitmap newbitmap = new Bitmap(Width, Height);
                Bitmap oldbitmap = (Bitmap)this.pictureBox1.Image;
                Color pixel;
                for (int x = 1; x < Width; x++)
                {
                    for (int y = 1; y < Height; y++)
                    {
                        int r, g, b;
                        pixel = oldbitmap.GetPixel(x, y);
                        r = 255 - pixel.R;
                        g = 255 - pixel.G;
                        b = 255 - pixel.B;
                        newbitmap.SetPixel(x, y, Color.FromArgb(r, g, b));
                    }
                }
                this.pictureBox1.Image = newbitmap;
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "信息提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
        }

二. 浮雕效果

原理: 對圖像像素點的像素值分別與相鄰像素點的像素值相減後加上128, 而後將其做爲新的像素點的值.

效果圖:

代碼實現:

       private void button1_Click(object sender, EventArgs e)
        {
            //以浮雕效果顯示圖像
            try
            {
                int Height = this.pictureBox1.Image.Height;
                int Width = this.pictureBox1.Image.Width;
                Bitmap newBitmap = new Bitmap(Width, Height);
                Bitmap oldBitmap = (Bitmap)this.pictureBox1.Image;
                Color pixel1, pixel2;
                for (int x = 0; x < Width - 1; x++)
                {
                    for (int y = 0; y < Height - 1; y++)
                    {
                        int r = 0, g = 0, b = 0;
                        pixel1 = oldBitmap.GetPixel(x, y);
                        pixel2 = oldBitmap.GetPixel(x + 1, y + 1);
                        r = Math.Abs(pixel1.R - pixel2.R + 128);
                        g = Math.Abs(pixel1.G - pixel2.G + 128);
                        b = Math.Abs(pixel1.B - pixel2.B + 128);
                        if (r > 255)
                            r = 255;
                        if (r < 0)
                            r = 0;
                        if (g > 255)
                            g = 255;
                        if (g < 0)
                            g = 0;
                        if (b > 255)
                            b = 255;
                        if (b < 0)
                            b = 0;
                        newBitmap.SetPixel(x, y, Color.FromArgb(r, g, b));
                    }
                }
                this.pictureBox1.Image = newBitmap;
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "信息提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
        }

三. 黑白效果

原理: 彩色圖像處理成黑白效果一般有3種算法；

(1).最大值法: 使每一個像素點的 R, G, B 值等於原像素點的 RGB (顏色值) 中最大的一個；

(2).平均值法: 使用每一個像素點的 R,G,B值等於原像素點的RGB值的平均值；

(3).加權平均值法: 對每一個像素點的 R, G, B值進行加權

---自認爲第三種方法作出來的黑白效果圖像最 "真實".

效果圖:

代碼實現:

        private void button1_Click(object sender, EventArgs e)
        {
            //以黑白效果顯示圖像
            try
            {
                int Height = this.pictureBox1.Image.Height;
                int Width = this.pictureBox1.Image.Width;
                Bitmap newBitmap = new Bitmap(Width, Height);
                Bitmap oldBitmap = (Bitmap)this.pictureBox1.Image;
                Color pixel;
                for (int x = 0; x < Width; x++)
                    for (int y = 0; y < Height; y++)
                    {
                        pixel = oldBitmap.GetPixel(x, y);
                        int r, g, b, Result = 0;
                        r = pixel.R;
                        g = pixel.G;
                        b = pixel.B;
                        //實例程序以加權平均值法產生黑白圖像
                        int iType =2;
                        switch (iType)
                        {
                            case 0://平均值法
                                Result = ((r + g + b) / 3);
                                break;
                            case 1://最大值法
                                Result = r > g ? r : g;
                                Result = Result > b ? Result : b;
                                break;
                            case 2://加權平均值法
                                Result = ((int)(0.7 * r) + (int)(0.2 * g) + (int)(0.1 * b));
                                break;
                        }
                        newBitmap.SetPixel(x, y, Color.FromArgb(Result, Result, Result));
                    }
                this.pictureBox1.Image = newBitmap;
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "信息提示");
            }
        }

四. 柔化效果

原理: 當前像素點與周圍像素點的顏色差距較大時取其平均值.

效果圖:

代碼實現:

        private void button1_Click(object sender, EventArgs e)
        {
            //以柔化效果顯示圖像
            try
            {
                int Height = this.pictureBox1.Image.Height;
                int Width = this.pictureBox1.Image.Width;
                Bitmap bitmap = new Bitmap(Width, Height);
                Bitmap MyBitmap = (Bitmap)this.pictureBox1.Image;
                Color pixel;
                //高斯模板
                int[] Gauss ={ 1, 2, 1, 2, 4, 2, 1, 2, 1 };
                for (int x = 1; x < Width - 1; x++)
                    for (int y = 1; y < Height - 1; y++)
                    {
                        int r = 0, g = 0, b = 0;
                        int Index = 0;
                        for (int col = -1; col <= 1; col++)
                            for (int row = -1; row <= 1; row++)
                            {
                                pixel = MyBitmap.GetPixel(x + row, y + col);
                                r += pixel.R * Gauss[Index];
                                g += pixel.G * Gauss[Index];
                                b += pixel.B * Gauss[Index];
                                Index++;
                            }
                        r /= 16;
                        g /= 16;
                        b /= 16;
                        //處理顏色值溢出
                        r = r > 255 ? 255 : r;
                        r = r < 0 ? 0 : r;
                        g = g > 255 ? 255 : g;
                        g = g < 0 ? 0 : g;
                        b = b > 255 ? 255 : b;
                        b = b < 0 ? 0 : b;
                        bitmap.SetPixel(x - 1, y - 1, Color.FromArgb(r, g, b));
                    }
                this.pictureBox1.Image = bitmap;
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "信息提示");
            }
        }

五.銳化效果

原理:突出顯示顏色值大(即造成形體邊緣)的像素點.

效果圖:

實現代碼:

       private void button1_Click(object sender, EventArgs e)
        {
            //以銳化效果顯示圖像
            try
            {
                int Height = this.pictureBox1.Image.Height;
                int Width = this.pictureBox1.Image.Width;
                Bitmap newBitmap = new Bitmap(Width, Height);
                Bitmap oldBitmap = (Bitmap)this.pictureBox1.Image;
                Color pixel;
                //拉普拉斯模板
                int[] Laplacian ={ -1, -1, -1, -1, 9, -1, -1, -1, -1 };
                for (int x = 1; x < Width - 1; x++)
                    for (int y = 1; y < Height - 1; y++)
                    {
                        int r = 0, g = 0, b = 0;
                        int Index = 0;
                        for (int col = -1; col <= 1; col++)
                            for (int row = -1; row <= 1; row++)
                           {
                                pixel = oldBitmap.GetPixel(x + row, y + col); r += pixel.R * Laplacian[Index];
                                g += pixel.G * Laplacian[Index];
                                b += pixel.B * Laplacian[Index];
                                Index++;
                            }
                        //處理顏色值溢出
                        r = r > 255 ? 255 : r;
                        r = r < 0 ? 0 : r;
                        g = g > 255 ? 255 : g;
                        g = g < 0 ? 0 : g;
                        b = b > 255 ? 255 : b;
                        b = b < 0 ? 0 : b;
                        newBitmap.SetPixel(x - 1, y - 1, Color.FromArgb(r, g, b));
                    }
                this.pictureBox1.Image = newBitmap;
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "信息提示");
            }
        }

六. 霧化效果

原理: 在圖像中引入必定的隨機值, 打亂圖像中的像素值

效果圖:

實現代碼:

       private void button1_Click(object sender, EventArgs e)
        {
            //以霧化效果顯示圖像
            try
            {
                int Height = this.pictureBox1.Image.Height;
                int Width = this.pictureBox1.Image.Width;
                Bitmap newBitmap = new Bitmap(Width, Height);
                Bitmap oldBitmap = (Bitmap)this.pictureBox1.Image;
                Color pixel;
                for (int x = 1; x < Width - 1; x++)
                    for (int y = 1; y < Height - 1; y++)
                    {
                        System.Random MyRandom = new Random();
                        int k = MyRandom.Next(123456);
                        //像素塊大小
                        int dx = x + k % 19;
                        int dy = y + k % 19;
                        if (dx >= Width)
                            dx = Width - 1;
                        if (dy >= Height)
                            dy = Height - 1;
                        pixel = oldBitmap.GetPixel(dx, dy);
                        newBitmap.SetPixel(x, y, pixel);
                    }
                this.pictureBox1.Image = newBitmap;
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "信息提示");
            }
        }

1、讀入圖像

在Visual C#中咱們可使用一個Picture Box控件來顯示圖片，以下：
        private void btnOpenImage_Click(object sender, EventArgs e)
        {
            OpenFileDialog ofd = new OpenFileDialog();
            ofd.Filter = "BMP Files(*.bmp)|*.bmp|JPG Files(*.jpg;*.jpeg)|*.jpg;*.jpeg|All Files(*.*)|*.*";
            ofd.CheckFileExists = true;
            ofd.CheckPathExists = true;
            if (ofd.ShowDialog() == DialogResult.OK)
            {
                //pbxShowImage.ImageLocation = ofd.FileName;
                bmp = new Bitmap(ofd.FileName);
                if (bmp==null)
                {
                    MessageBox.Show("加載圖片失敗!", "錯誤");
                    return;
                }
                pbxShowImage.Image = bmp;
                ofd.Dispose();
            }
        }
其中bmp爲類的一個對象：private Bitmap bmp=null;
在使用Bitmap類和BitmapData類以前，須要使用using System.Drawing.Imaging;
2、保存圖像
        private void btnSaveImage_Click(object sender, EventArgs e)
        {
            if (bmp == null) return;

            SaveFileDialog sfd = new SaveFileDialog();
            sfd.Filter = "BMP Files(*.bmp)|*.bmp|JPG Files(*.jpg;*.jpeg)|*.jpg;*.jpeg|All Files(*.*)|*.*";
            if (sfd.ShowDialog() == DialogResult.OK)
            {
                pbxShowImage.Image.Save(sfd.FileName);
                MessageBox.Show("保存成功!","提示");
                sfd.Dispose();
            }
        }
3、對像素的訪問
咱們能夠來創建一個GrayBitmapData類來作相關的處理。整個類的程序以下：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
using System.Drawing.Imaging;
using System.Windows.Forms;

namespace ImageElf
{
    class GrayBitmapData
    {
        public byte[,] Data;//保存像素矩陣
        public int Width;//圖像的寬度
        public int Height;//圖像的高度

        public GrayBitmapData()
        {
            this.Width = 0;
            this.Height = 0;
            this.Data = null;
        }

        public GrayBitmapData(Bitmap bmp)
        {
            BitmapData bmpData = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb);
            this.Width = bmpData.Width;
            this.Height = bmpData.Height;
            Data = new byte[Height, Width];
            unsafe
            {
                byte* ptr = (byte*)bmpData.Scan0.ToPointer();
                for (int i = 0; i < Height; i++)
                {
                    for (int j = 0; j < Width; j++)
                    {
    //將24位的RGB彩色圖轉換爲灰度圖
                        int temp = (int)(0.114 * (*ptr++)) + (int)(0.587 * (*ptr++))+(int)(0.299 * (*ptr++));
                        Data[i, j] = (byte)temp;
                    }
                    ptr += bmpData.Stride - Width * 3;//指針加上填充的空白空間
                }
            }
            bmp.UnlockBits(bmpData);
        }

        public GrayBitmapData(string path)
            : this(new Bitmap(path))
        {
        }

        public Bitmap ToBitmap()
        {
            Bitmap bmp=new Bitmap(Width,Height,PixelFormat.Format24bppRgb);
            BitmapData bmpData=bmp.LockBits(new Rectangle(0,0,Width,Height),ImageLockMode.WriteOnly,PixelFormat.Format24bppRgb);
            unsafe
            {
                byte* ptr=(byte*)bmpData.Scan0.ToPointer();
                for(int i=0;i<Height;i++)
                {
                    for(int j=0;j<Width;j++)
                    {
                        *(ptr++)=Data[i,j];
                        *(ptr++)=Data[i,j];
                        *(ptr++)=Data[i,j];
                    }
                    ptr+=bmpData.Stride-Width*3;
                }
            }
            bmp.UnlockBits(bmpData);
            return bmp;
        }

        public void ShowImage(PictureBox pbx)
        {
            Bitmap b = this.ToBitmap();
            pbx.Image = b;
            //b.Dispose();
        }

        public void SaveImage(string path)
        {
            Bitmap b=ToBitmap();
            b.Save(path);
            //b.Dispose();
        }
//均值濾波
        public void AverageFilter(int windowSize)
        {
            if (windowSize % 2 == 0)
            {
                return;
            }

            for (int i = 0; i < Height; i++)
            {
                for (int j = 0; j < Width; j++)
                {
                    int sum = 0;
                    for (int g = -(windowSize - 1) / 2; g <= (windowSize - 1) / 2; g++)
                    {
                        for (int k = -(windowSize - 1) / 2; k <= (windowSize - 1) / 2; k++)
                        {
                            int a = i + g, b = j + k;
                            if (a < 0) a = 0;
                            if (a > Height - 1) a = Height - 1;
                            if (b < 0) b = 0;
                            if (b > Width - 1) b = Width - 1;
                            sum += Data[a, b];
                        }
                    }
                    Data[i,j]=(byte)(sum/(windowSize*windowSize));
                }
            }
        }
//中值濾波
        public void MidFilter(int windowSize)
        {
            if (windowSize % 2 == 0)
            {
                return;
            }

            int[] temp = new int[windowSize * windowSize];
            byte[,] newdata = new byte[Height, Width];
            for (int i = 0; i < Height; i++)
            {
                for (int j = 0; j < Width; j++)
                {
                    int n = 0;
                    for (int g = -(windowSize - 1) / 2; g <= (windowSize - 1) / 2; g++)
                    {
                        for (int k = -(windowSize - 1) / 2; k <= (windowSize - 1) / 2; k++)
                        {
                            int a = i + g, b = j + k;
                            if (a < 0) a = 0;
                            if (a > Height - 1) a = Height - 1;
                            if (b < 0) b = 0;
                            if (b > Width - 1) b = Width - 1;
                            temp[n++]= Data[a, b];
                        }
                    }
                    newdata[i, j] = GetMidValue(temp,windowSize*windowSize);
                }
            }

            for (int i = 0; i < Height; i++)
            {
                for (int j = 0; j < Width; j++)
                {
                    Data[i, j] = newdata[i, j];
                }
            }
        }
//得到一個向量的中值
        private byte GetMidValue(int[] t, int length)
        {
            int temp = 0;
            for (int i = 0; i < length - 2; i++)
            {
                for (int j = i + 1; j < length - 1; j++)
                {
                    if (t[i] > t[j])
                    {
                        temp = t[i];
                        t[i] = t[j];
                        t[j] = temp;
                    }
                }
            }

            return (byte)t[(length - 1) / 2];
        }
//一種新的濾波方法，是亮的更亮、暗的更暗
        public void NewFilter(int windowSize)
        {
            if (windowSize % 2 == 0)
            {
                return;
            }

            for (int i = 0; i < Height; i++)
            {
                for (int j = 0; j < Width; j++)
                {
                    int sum = 0;
                    for (int g = -(windowSize - 1) / 2; g <= (windowSize - 1) / 2; g++)
                    {
                        for (int k = -(windowSize - 1) / 2; k <= (windowSize - 1) / 2; k++)
                        {
                            int a = i + g, b = j + k;
                            if (a < 0) a = 0;
                            if (a > Height - 1) a = Height - 1;
                            if (b < 0) b = 0;
                            if (b > Width - 1) b = Width - 1;
                            sum += Data[a, b];
                        }
                    }
                    double avg = (sum+0.0) / (windowSize * windowSize);
                    if (avg / 255 < 0.5)
                    {
                        Data[i, j] = (byte)(2 * avg / 255 * Data[i, j]);
                    }
                    else
                    {
                        Data[i,j]=(byte)((1-2*(1-avg/255.0)*(1-Data[i,j]/255.0))*255);
                    }
                }
            }
        }
//直方圖均衡
        public void HistEqual()
        {
            double[] num = new double[256] ;
            for(int i=0;i<256;i++) num[i]=0;

            for (int i = 0; i < Height; i++)
            {
                for (int j = 0; j < Width; j++)
                {
                    num[Data[i, j]]++;
                }
            }

            double[] newGray = new double[256];
            double n = 0;
            for (int i = 0; i < 256; i++)
            {
                n += num[i];
                newGray[i] = n * 255 / (Height * Width);
            }

            for (int i = 0; i < Height; i++)
            {
                for (int j = 0; j < Width; j++)
                {
                    Data[i,j]=(byte)newGray[Data[i,j]];
                }
            }
        }

}
}
在GrayBitmapData類中，只要咱們對一個二維數組Data進行一系列的操做就是對圖片的操做處理。在窗口上，咱們可使用
一個按鈕來作各類調用：
//均值濾波
        private void btnAvgFilter_Click(object sender, EventArgs e)
        {
            if (bmp == null) return;
            GrayBitmapData gbmp = new GrayBitmapData(bmp);
            gbmp.AverageFilter(3);
            gbmp.ShowImage(pbxShowImage);
        }
//轉換爲灰度圖
        private void btnToGray_Click(object sender, EventArgs e)
        {
            if (bmp == null) return;
            GrayBitmapData gbmp = new GrayBitmapData(bmp);
            gbmp.ShowImage(pbxShowImage);
        }

4、總結

在Visual c#中對圖像進行處理或訪問，須要先創建一個Bitmap對象，而後經過其LockBits方法來得到一個BitmapData類的對象，而後經過得到其像素數據的首地址來對Bitmap對象的像素數據進行操做。固然，一種簡單可是速度慢的方法是用Bitmap類的GetPixel和SetPixel方法。其中BitmapData類的Stride屬性爲每行像素所佔的字節。

(轉自：http://blog.csdn.net/jiangxinyu/article/details/6222322/)

C# colorMatrix 對圖片的處理 : 亮度調整抓屏翻轉隨鼠標畫矩形

1.圖片亮度處理

private void btn_Grap_Click(object sender, EventArgs e)

{

//亮度百分比

int percent = 50;

Single v = 0.006F * percent;

Single[][] matrix = {

new Single[] { 1, 0, 0, 0, 0 },

new Single[] { 0, 1, 0, 0, 0 },

new Single[] { 0, 0, 1, 0, 0 },

new Single[] { 0, 0, 0, 1, 0 },

new Single[] { v, v, v, 0, 1 }

};

System.Drawing.Imaging.ColorMatrix cm = new System.Drawing.Imaging.ColorMatrix(matrix);

System.Drawing.Imaging.ImageAttributes attr = new System.Drawing.Imaging.ImageAttributes();

attr.SetColorMatrix(cm);

//Image tmp

Image tmp = Image.FromFile("1.png");

this.pictureBox_Src.Image = Image.FromFile("1.png");

Graphics g = Graphics.FromImage(tmp);

try

{

Rectangle destRect = new Rectangle(0, 0, tmp.Width, tmp.Height);

g.DrawImage(tmp, destRect, 0, 0, tmp.Width, tmp.Height, GraphicsUnit.Pixel, attr);

}

finally

{

g.Dispose();

}

this.pictureBox_Dest.Image = (Image)tmp.Clone();

}

2.抓屏將生成的圖片顯示在pictureBox

private void btn_Screen_Click(object sender, EventArgs e)

{

Image myImage = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height);

Graphics g = Graphics.FromImage(myImage);

g.CopyFromScreen(new Point(0, 0), new Point(0, 0), new Size(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height));

//IntPtr dc1 = g.GetHdc(); //此處這兩句多餘，具體看最後GetHdc()定義

//g.ReleaseHdc(dc1);

g.Dispose();

this.pictureBox_Src.SizeMode = PictureBoxSizeMode.StretchImage;

this.pictureBox_Src.Image = myImage;

myImage.Save("Screen", ImageFormat.Png);

}

3.翻轉

private void btn_RotateFlip_Click(object sender, EventArgs e)

{

this.pictureBox_Src.Image = Image.FromFile("1.png");

Image tmp = Image.FromFile("1.png");

tmp.RotateFlip(RotateFlipType.Rotate90FlipNone);

this.pictureBox_Dest.Image = tmp;

}

4.跟隨鼠標在 pictureBox的圖片上畫矩形

private int intStartX = 0;

private int intStartY = 0;

private bool isMouseDraw = false;

private void pictureBox_Src_MouseDown(object sender, MouseEventArgs e)

{

isMouseDraw = true;

intStartX = e.X;

intStartY = e.Y;

}

private void pictureBox_Src_MouseMove(object sender, MouseEventArgs e)

{

if (isMouseDraw)

{

try

{

//Image tmp = Image.FromFile("1.png");

Graphics g = this.pictureBox_Src.CreateGraphics();

//清空上次畫下的痕跡

g.Clear(this.pictureBox_Src.BackColor);

Brush brush = new SolidBrush(Color.Red);

Pen pen = new Pen(brush, 1);

pen.DashStyle = DashStyle.Solid;

g.DrawRectangle(pen, new Rectangle(intStartX > e.X ? e.X : intStartX, intStartY > e.Y ? e.Y : intStartY, Math.Abs(e.X - intStartX), Math.Abs(e.Y - intStartY)));

g.Dispose();

//this.pictureBox_Src.Image = tmp;

}

catch (Exception ex)

{

ex.ToString();

}

private void pictureBox_Src_MouseUp(object sender, MouseEventArgs e)

{

isMouseDraw = false;

intStartX = 0;

intStartY = 0;

}

5.取灰度

private void btn_GetGray_Click(object sender, EventArgs e)

{

this.pictureBox_Src.Image = Image.FromFile("1.png");

Bitmap currentBitmap = new Bitmap(this.pictureBox_Src.Image);

Graphics g = Graphics.FromImage(currentBitmap);

ImageAttributes ia = new ImageAttributes();

float[][] colorMatrix = {

new float[] {0.299f, 0.299f, 0.299f, 0, 0},

new float[] {0.587f, 0.587f, 0.587f, 0, 0},

new float[] {0.114f, 0.114f, 0.114f, 0, 0},

new float[] {0, 0, 0, 1, 0},

new float[] {0, 0, 0, 0, 1}

};

ColorMatrix cm = new ColorMatrix(colorMatrix);

ia.SetColorMatrix(cm, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);

g.DrawImage(currentBitmap, new Rectangle(0, 0, currentBitmap.Width, currentBitmap.Height), 0, 0, currentBitmap.Width, currentBitmap.Height, GraphicsUnit.Pixel, ia);

this.pictureBox_Dest.Image = (Image)(currentBitmap.Clone());

g.Dispose();

}

Graphics.GetHdc 方法

.NET Framework 4

獲取與此 Graphics 關聯的設備上下文的句柄。

命名空間： System.Drawing
程序集： System.Drawing（在 System.Drawing.dll 中）

語法

[SecurityPermissionAttribute(SecurityAction.LinkDemand, Flags =

SecurityPermissionFlag.UnmanagedCode)]

public IntPtr GetHdc()

返回值

類型：System.IntPtr
與此 Graphics 關聯的設備上下文的句柄。

實現

IDeviceContext.GetHdc()

備註

設備上下文是一個基於 GDI 的 Windows 結構，它定義一組圖形對象及其關聯的特性，以及影響輸出的圖形模式。此方法返回該設備上下文（字體除外）。因爲未選擇字體，使用 GetHdc 方法返回的句柄對 FromHdc 方法進行調用將會失敗。

GetHdc 方法調用和 ReleaseHdc 方法調用必須成對出現。在 GetHdc 和 ReleaseHdc 方法對的範圍內，一般僅調用 GDI 函數。在該範圍內對 Graphics（它產生 hdc 參數）的 GDI+ 方法的調用因 ObjectBusy 錯誤而失敗。此外，GDI+ 忽略後續操做中對 hdc 參數的 Graphics 所作的全部狀態更改。

示例

下面的代碼示例設計爲與 Windows 窗體一塊兒使用，它須要 PaintEventArgse，即 Paint 事件處理程序的一個參數。該示例演示如何調用 Windows GDI 函數以執行與 GDI+ Graphics 方法相同的任務。代碼執行下列操做：