反转图像返回黑色图像
我想反转一个Image对象。 目前我的代码如下所示：
private Image Invert(Image img) { var bmpPicture = new Bitmap(img.Width, img.Height); var iaPicture = new ImageAttributes(); var cmPicture = new ColorMatrix { Matrix00 = -1, Matrix11 = -1, Matrix22 = -1 }; iaPicture.SetColorMatrix(cmPicture); var gfxPicture = Graphics.FromImage(img); var rctPicture = new Rectangle(0, 0, img.Width, img.Height); gfxPicture.DrawImage(img, rctPicture, 0, 0, img.Width, img.Height, GraphicsUnit.Pixel, iaPicture); return bmpPicture; } 但是，当我运行它并在PictureBox显示它时，结果是一个黑色图像。 我在Windows 8 Release预览版的Visual Studio 2012中运行它。 如果有更好的方法，请告诉我。 谢谢。
试试这个： http ： //mariusbancila.ro/blog/2009/11/13/using-colormatrix-for-creating-negative-image/
public Bitmap Transform(Bitmap source) { //create a blank bitmap the same size as original Bitmap newBitmap = new Bitmap(source.Width, source.Height); //get a graphics object from the new image Graphics g = Graphics.FromImage(newBitmap); // create the negative color matrix ColorMatrix colorMatrix = new ColorMatrix(new float[][] { new float[] {-1, 0, 0, 0, 0}, new float[] {0, -1, 0, 0, 0}, new float[] {0, 0, -1, 0, 0}, new float[] {0, 0, 0, 1, 0}, new float[] {1, 1, 1, 0, 1} }); // create some image attributes ImageAttributes attributes = new ImageAttributes(); attributes.SetColorMatrix(colorMatrix); g.DrawImage(source, new Rectangle(0, 0, source.Width, source.Height), 0, 0, source.Width, source.Height, GraphicsUnit.Pixel, attributes); //dispose the Graphics object g.Dispose(); return newBitmap; }
使用ColorMatrix进行像素操作的快速替代方法：
public static void BitmapInvertColors(Bitmap bitmapImage) { var bitmapRead = bitmapImage.LockBits(new Rectangle(0, 0, bitmapImage.Width, bitmapImage.Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppPArgb); var bitmapLength = bitmapRead.Stride * bitmapRead.Height; var bitmapBGRA = new byte[bitmapLength]; Marshal.Copy(bitmapRead.Scan0, bitmapBGRA, 0, bitmapLength); bitmapImage.UnlockBits(bitmapRead); for (int i = 0; i < bitmapLength; i += 4) { bitmapBGRA[i] = (byte)(255 - bitmapBGRA[i]); bitmapBGRA[i + 1] = (byte)(255 - bitmapBGRA[i + 1]); bitmapBGRA[i + 2] = (byte)(255 - bitmapBGRA[i + 2]); // [i + 3] = ALPHA. } var bitmapWrite = bitmapImage.LockBits(new Rectangle(0, 0, bitmapImage.Width, bitmapImage.Height), ImageLockMode.WriteOnly, PixelFormat.Format32bppPArgb); Marshal.Copy(bitmapBGRA, 0, bitmapWrite.Scan0, bitmapLength); bitmapImage.UnlockBits(bitmapWrite); }
通过倒置你的意思是创造一个负面的？ 如果是，这里是一个片段：
public void ApplyInvert() { byte A, R, G, B; Color pixelColor; for (int y = 0; y < bitmapImage.Height; y++) { for (int x = 0; x < bitmapImage.Width; x++) { pixelColor = bitmapImage.GetPixel(x, y); A = pixelColor.A; R = (byte)(255 - pixelColor.R); G = (byte)(255 - pixelColor.G); B = (byte)(255 - pixelColor.B); bitmapImage.SetPixel(x, y, Color.FromArgb((int)A, (int)R, (int)G, (int)B)); } } }
来自： http ： //www.smokycogs.com/blog/image-processing-in-c-sharp-inverting-an-image/
如果您想了解有关您的问题和颜色矩阵的更多信息，请继续以下链接： http ： //www.bobpowell.net/negativeimage.htm
您没有设置Matrix33或Matrix44 。 我的理解是Matrix33将是alpha组件，因此我怀疑你是在使整个图像变得透明。
尝试设置Matrix33 = 1 。
我使用WPF和这个库来创建反转（负面）效果。
VB版Dan的答案。 它就像一个魅力！
Public Function Transform(source As Bitmap) As Bitmap 'create a blank bitmap the same size as original Dim newBitmap As New Bitmap(source.Width, source.Height) 'get a graphics object from the new image Dim g As Graphics = Graphics.FromImage(newBitmap) ' create the negative color matrix Dim colorMatrix As New ColorMatrix(New Single()() {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() {1, 1, 1, 0, 1}}) ' create some image attributes Dim attributes As New ImageAttributes() attributes.SetColorMatrix(colorMatrix) g.DrawImage(source, New Rectangle(0, 0, source.Width, source.Height), 0, 0, source.Width, source.Height, _ GraphicsUnit.Pixel, attributes) 'dispose the Graphics object g.Dispose() Return newBitmap End Function
我使用“SIMD支持的向量”使代码比指针更快。它在System.Numerics namespace.But下使用这些类之前你需要从NuGet获取System.Numerics的更新。只搜索System.Numerics.Anyways这是我的用于反转图像的类
public class VBitmap : IDisposable { public short Width { get; private set; } public short Height { get; private set; } public int Stride { get; private set; } public int PixelLenght { get; private set; } public byte BytesperPixel { get; private set; } public PixelFormat PixelFormat { get; private set; } public byte[] Pixels { get; private set; } public VBitmap(string path) { using (Bitmap bmp = new Bitmap(path)) { BitmapData bmpdata = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.ReadOnly, bmp.PixelFormat); Width = checked((short)bmp.Width); Height = checked((short)bmp.Height); Stride = bmpdata.Stride; PixelLenght = Stride * Height; BytesperPixel = checked((byte)(Stride / Width)); PixelLenght = (PixelLenght % 16) != 0 ? PixelLenght + (PixelLenght % 16) : PixelLenght; PixelFormat = bmp.PixelFormat; Pixels = new byte[PixelLenght]; Marshal.Copy(bmpdata.Scan0, Pixels, 0, PixelLenght); bmp.UnlockBits(bmpdata); } } ~VBitmap() { Dispose(); } public void InvertPixels() { byte[] resultarray = Pixels; unsafe { fixed (byte* result_ptr = resultarray) { for (int i = 0; i < PixelLenght; i += 16) (~new Vector(Pixels, i)).CopyTo(resultarray, i); } } } public void InvertPixels(string name) { byte[] resultarray = Pixels; unsafe { fixed (byte* result_ptr = resultarray) { for (int i = 0; i < PixelLenght; i += 16) (~new Vector (Pixels, i)).CopyTo(resultarray, i); SaveImage(name); } } } public unsafe void SaveImage(string name) { fixed (byte* p_ptr = Pixels) { using (Bitmap resultbmp = new Bitmap(Width, Height, Stride, PixelFormat, (IntPtr)p_ptr)) { resultbmp.Save(name, ImageFormat.Jpeg); } } } public void Dispose() { Width = 0; Height = 0; Stride = 0; PixelLenght = 0; BytesperPixel = 0; Pixels = null; GC.Collect(); } }
用法。注意：要从向量中获得最佳性能，您需要在发布模式下运行代码：
static void Main(string[] args) { new VBitmap("testp.png").InvertPixels("qq.jpg");//Inverts the given bitmap and saves it. }
var gfxPicture = Graphics.FromImage(img);
==>
var gfxPicture = Graphics.FromImage(bmpPicture);
DrawImage可能会扭曲图像，GetPixel很慢，请尝试WPF成像API