【C#】圖片處理（底片，黑白，銳化，柔化，浮雕，霧化）

通過GDI+對圖片數據進行處理，下面列出各個效果的算法

對於讀取圖片的每個像素顏色的速度非常慢，這里使用LockBitmap類來對圖片像素進行操作，LockBitmap類的定義看這里

http://www.cnblogs.com/bomo/archive/2013/02/26/2934055.html

 1、旋轉（90度，180度，270度）

        //旋轉90,180,270
        public Bitmap RotateImage(Bitmap bmp, int angle)
        {
            if (angle != 90 && angle != 180 && angle != 270)
            {
                return null;
            }
            int width = bmp.Width;
            int height = bmp.Height;

            if (angle == 90)
            {
                Bitmap newbmp = new Bitmap(height, width);
                using (Graphics g = Graphics.FromImage(newbmp))
                {
                    Point[] destinationPoints = {
                        new Point(height, 0), // destination for upper-left point of original
                        new Point(height, width),// destination for upper-right point of original
                        new Point(0, 0)}; // destination for lower-left point of original
                    g.DrawImage(bmp, destinationPoints);
                }
                return newbmp;
            }

            if (angle == 180)
            {
                Bitmap newbmp = new Bitmap(width, height);
                using (Graphics g = Graphics.FromImage(newbmp))
                {
                    Point[] destinationPoints = {
                        new Point(width, height), // destination for upper-left point of original
                        new Point(0, height),// destination for upper-right point of original
                        new Point(width, 0)}; // destination for lower-left point of original
                    g.DrawImage(bmp, destinationPoints);
                }
                return newbmp;
            }

            if(angle == 270)
            {
                Bitmap newbmp = new Bitmap(height, width);
                using (Graphics g = Graphics.FromImage(newbmp))
                {
                    Point[] destinationPoints = {
                        new Point(0, width), // destination for upper-left point of original
                        new Point(0, 0),// destination for upper-right point of original
                        new Point(height, width)}; // destination for lower-left point of original
                    g.DrawImage(bmp, destinationPoints);
                }
                return newbmp;
            }
            return null;
        }

2、重設大小

        //重設大小
        public Bitmap ResizeImage(Bitmap bmp, Size size)
        {
            Bitmap newbmp = new Bitmap(size.Width, size.Height);
            using (Graphics g = Graphics.FromImage(newbmp))
            {
                g.DrawImage(bmp, new Rectangle(Point.Empty, size));
            }
            return newbmp;
        }

3、底片效果（反色）（255-r, 255-g, 255-b）

        //底片
        public Bitmap NegativeImage(Bitmap bmp)
        {
            int height = bmp.Height;
            int width = bmp.Width;
            Bitmap newbmp = new Bitmap(width, height);

            LockBitmap lbmp = new LockBitmap(bmp);
            LockBitmap newlbmp = new LockBitmap(newbmp);
            lbmp.LockBits();
            newlbmp.LockBits();

            Color pixel;
            for (int x = 1; x < width; x++)
            {
                for (int y = 1; y < height; y++)
                {
                    int r, g, b;
                    pixel = lbmp.GetPixel(x, y);
                    r = 255 - pixel.R;
                    g = 255 - pixel.G;
                    b = 255 - pixel.B;
                    newlbmp.SetPixel(x, y, Color.FromArgb(r, g, b));
                }
            }
            lbmp.UnlockBits();
            newlbmp.UnlockBits();
            return newbmp;
        }

4、黑白效果

        //黑白
        public Bitmap GrayImage(Bitmap bmp, int type)
        {
            int height = bmp.Height;
            int width = bmp.Width;
            Bitmap newbmp = new Bitmap(width, height);

            LockBitmap lbmp = new LockBitmap(bmp);
            LockBitmap newlbmp = new LockBitmap(newbmp);
            lbmp.LockBits();
            newlbmp.LockBits();

            Color pixel;
            for (int x = 0; x < width; x++)
            {
                for (int y = 0; y < height; y++)
                {
                    pixel = lbmp.GetPixel(x, y);
                    int r, g, b, Result = 0;
                    r = pixel.R;
                    g = pixel.G;
                    b = pixel.B;
                    switch (type)
                    {
                        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)(0.3 * r) + (int)(0.59 * g) + (int)(0.11 * b));
                            break;
                    }
                    newlbmp.SetPixel(x, y, Color.FromArgb(Result, Result, Result));
                }
            }
            lbmp.UnlockBits();
            newlbmp.UnlockBits();
            return newbmp;
        }

5、浮雕：找出附近的像素點r1，abs（r-r2+128）

        //浮雕
        public Bitmap EmbossmentImage(Bitmap bmp)
        {
            int height = bmp.Height;
            int width = bmp.Width;
            Bitmap newbmp = new Bitmap(width, height);

            LockBitmap lbmp = new LockBitmap(bmp);
            LockBitmap newlbmp = new LockBitmap(newbmp);
            lbmp.LockBits();
            newlbmp.LockBits();

            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 = lbmp.GetPixel(x, y);
                    pixel2 = lbmp.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;
                    newlbmp.SetPixel(x, y, Color.FromArgb(r, g, b));
                }
            }
            lbmp.UnlockBits();
            newlbmp.UnlockBits();
            return newbmp;
        }

6、柔化

        //柔化
        public Bitmap SoftenImage(Bitmap bmp)
        {
            int height = bmp.Height;
            int width = bmp.Width;
            Bitmap newbmp = new Bitmap(width, height);

            LockBitmap lbmp = new LockBitmap(bmp);
            LockBitmap newlbmp = new LockBitmap(newbmp);
            lbmp.LockBits();
            newlbmp.LockBits();

            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 = lbmp.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;
                    newlbmp.SetPixel(x - 1, y - 1, Color.FromArgb(r, g, b));
                }
            }
            lbmp.UnlockBits();
            newlbmp.UnlockBits();
            return newbmp;
        }

 

7、銳化

        //銳化
        public Bitmap SharpenImage(Bitmap bmp)
        {
            int height = bmp.Height;
            int width = bmp.Width;
            Bitmap newbmp = new Bitmap(width, height);

            LockBitmap lbmp = new LockBitmap(bmp);
            LockBitmap newlbmp = new LockBitmap(newbmp);
            lbmp.LockBits();
            newlbmp.LockBits();

            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 = lbmp.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;
                    newlbmp.SetPixel(x - 1, y - 1, Color.FromArgb(r, g, b));
                }
            }
            lbmp.UnlockBits();
            newlbmp.UnlockBits();
            return newbmp;
        }

8、霧化

        //霧化
        public Bitmap AtomizationImage(Bitmap bmp)
        {
            int height = bmp.Height;
            int width = bmp.Width;
            Bitmap newbmp = new Bitmap(width, height);

            LockBitmap lbmp = new LockBitmap(bmp);
            LockBitmap newlbmp = new LockBitmap(newbmp);
            lbmp.LockBits();
            newlbmp.LockBits();

            System.Random MyRandom = new Random();
            Color pixel;
            for (int x = 1; x < width - 1; x++)
            {
                for (int y = 1; y < height - 1; y++)
                {
                    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 = lbmp.GetPixel(dx, dy);
                    newlbmp.SetPixel(x, y, pixel);
                }
            }
            lbmp.UnlockBits();
            newlbmp.UnlockBits();
            return newbmp;
        }