public static unsafe void CopyChannel(ImageChannel <TPixel> src, ImageChannel <TPixel> dst, System.Drawing.Point start, System.Drawing.Rectangle region, System.Drawing.Point destAnchor) { if (start.X >= src.Width || start.Y >= src.Height) { return; } int startSrcX = Math.Max(0, start.X); int startSrcY = Math.Max(0, start.Y); int endSrcX = Math.Min(start.X + region.Width, src.Width); int endSrcY = Math.Min(start.Y + region.Height, src.Height); int offsetX = start.X < 0 ? -start.X : 0; int offsetY = start.Y < 0 ? -start.Y : 0; offsetX = destAnchor.X + offsetX; offsetY = destAnchor.Y + offsetY; int startDstX = Math.Max(0, offsetX); int startDstY = Math.Max(0, offsetY); offsetX = offsetX < 0 ? -offsetX : 0; offsetY = offsetY < 0 ? -offsetY : 0; startSrcX += offsetX; startSrcY += offsetY; int step = dst.Step; int endDstX = Math.Min(destAnchor.X + region.Width, dst.Width); int endDstY = Math.Min(destAnchor.Y + region.Height, dst.Height); int copyWidth = Math.Min(endSrcX - startSrcX, endDstX - startDstX) * step; int copyHeight = Math.Min(endSrcY - startSrcY, endDstY - startDstY); if (copyWidth <= 0 || copyHeight <= 0) { return; } int srcWidth = src.Width * step; int dstWidth = dst.Width * step; TPixel *srcLine = (TPixel *)(src.StartIntPtr) + srcWidth * startSrcY + startSrcX; TPixel *dstLine = (TPixel *)dst.StartIntPtr + dstWidth * step * startDstY + startDstX; TPixel *endSrcLine = srcLine + srcWidth * copyHeight; while (srcLine < endSrcLine) { TPixel *pSrc = srcLine; TPixel *endPSrc = pSrc + copyWidth; TPixel *pDst = dstLine; while (pSrc < endPSrc) { *pDst = *pSrc; pSrc += step; pDst += step; } srcLine += srcWidth; dstLine += dstWidth; } }
public static unsafe void FillImage(ImageChannel <TPixel> img, TPixel value) { int step = img.Step; TPixel *start = (TPixel *)img.StartIntPtr; TPixel *end = start += img.Length * img.Step; while (start != end) { *start = value; start += step; } }
public static unsafe void CopyToIntChannel(ImageChannel <TPixel> src, ImageChannel <Int32> dst) { if (src.Length != dst.Length) { throw new InvalidOperationException("The two channels are not the same length."); } int length = src.Length; int srcStep = src.Step; int dstStep = dst.Step; TPixel *srcStart = (TPixel *)src.StartIntPtr; TPixel *srcEnd = srcStart + length * srcStep; Int32 * dstStart = (Int32 *)dst.StartIntPtr; while (srcStart != srcEnd) { *dstStart = (Int32)(*srcStart); srcStart += srcStep; dstStart += dstStep; } }
public static unsafe void ApplyConvolution(ImageChannel <TPixel> img, ConvolutionKernel k) { if (img.Width < 2 || img.Height < 2) { return; } int widthTypeScaled = img.Width * img.Step; int kernelHeight = k.Width; int kernelWidth = k.Height; int scale = k.Scale; int[,] kernel = k.Kernel; int extend = Math.Max(kernelWidth, kernelHeight) / 2; ImageChannel <TPixel> maskImage = new ImageChannel <TPixel>(img.Width + extend * 2, img.Height + extend * 2); FillImage(maskImage, (TPixel)0); //这里效率不高。原本只需要填充四周扩大的部分即可 CopyChannel(img, maskImage, new System.Drawing.Point(0, 0), new System.Drawing.Rectangle(0, 0, img.Width, img.Height), new System.Drawing.Point(extend, extend)); int step = img.Step; int maskStep = maskImage.Step; int width = img.Width; int height = img.Height; TPixel *start = (TPixel *)img.StartIntPtr; TPixel *maskStart = (TPixel *)maskImage.StartIntPtr; // 复制边界像素 TPixel *dstStart = maskStart + extend; int maskWidth = img.Width + extend * 2; int maskHeight = img.Height + extend * 2; TPixel *dstContentStart = maskStart + extend + maskWidth * extend; // 复制上方的像素 for (int y = 0; y < extend; y++) { TPixel *lineStart = dstStart + y * maskWidth; TPixel *lineEnd = lineStart + width; TPixel *copyStart = dstContentStart; while (lineStart != lineEnd) { *lineStart = *copyStart; lineStart++; copyStart++; } } // 复制下方的像素 for (int y = height + extend; y < maskHeight; y++) { TPixel *lineStart = dstStart + y * maskWidth; TPixel *lineEnd = lineStart + width; TPixel *copyStart = dstContentStart + height * maskWidth - maskWidth; while (lineStart != lineEnd) { *lineStart = *copyStart; lineStart++; copyStart++; } } // 复制左右两侧的像素 TPixel *dstLine = maskStart + maskWidth * extend; TPixel p = default(TPixel); for (int y = extend; y < height + extend; y++) { p = dstLine[extend]; for (int x = 0; x < extend; x++) { dstLine[x] = p; } p = dstLine[extend + width - 1]; for (int x = width + extend; x < maskWidth; x++) { dstLine[x] = p; } dstLine += maskWidth; } // 复制四个角落的像素 // 左上 p = dstContentStart[0]; for (int y = 0; y < extend; y++) { for (int x = 0; x < extend; x++) { maskStart[y * maskWidth + x] = p; } } // 右上 p = dstContentStart[width - 1]; for (int y = 0; y < extend; y++) { for (int x = width + extend; x < maskWidth; x++) { maskStart[y * maskWidth + x] = p; } } // 左下 p = dstContentStart[(height - 1) * maskWidth]; for (int y = height + extend; y < maskHeight; y++) { for (int x = 0; x < extend; x++) { maskStart[y * maskWidth + x] = p; } } // 右下 p = dstContentStart[(height - 1) * maskWidth + width - 1]; for (int y = height + extend; y < maskHeight; y++) { for (int x = width + extend; x < maskWidth; x++) { maskStart[y * maskWidth + x] = p; } } if (scale == 1) { for (int h = 0; h < height; h++) { for (int w = 0; w < width; w++) { TValue val = 0; for (int kw = 0; kw < kernelWidth; kw++) { for (int kh = 0; kh < kernelHeight; kh++) { val += maskStart[(h + kh) * maskWidth + (w + kw)] * kernel[kh, kw]; } } start[h * widthTypeScaled + w] = (TPixel)val; } } } else { double factor = 1.0 / scale; for (int h = 0; h < height; h++) { for (int w = 0; w < width; w++) { TValue val = 0; for (int kw = 0; kw < kernelWidth; kw++) { for (int kh = 0; kh < kernelHeight; kh++) { val += maskStart[(h + kh) * maskWidth + (w + kw)] * kernel[kh, kw]; } } start[h * widthTypeScaled + w] = (TPixel)(val * factor); } } } maskImage.Dispose(); }