■ Bitmap 클래스에서 회선 필터(Convolution Filter)를 사용하는 방법을 보여준다.
▶ 예제 코드 (C#)
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using System.Drawing; using System.Drawing.Imaging; using System.Runtime.InteropServices; #region 회선 필터 적용하기 - ApplyConvolutionFilter(sourceBitmap, filterArray, factor, bias, grayscale) /// <summary> /// 회선 필터 적용하기 /// </summary> /// <param name="sourceBitmap">소스 비트맵</param> /// <param name="filterArray">필터 배열</param> /// <param name="factor">팩터</param> /// <param name="bias">바이어스</param> /// <param name="grayscale">회색조 여부</param> /// <returns>비트맵</returns> public static Bitmap ApplyConvolutionFilter ( Bitmap sourceBitmap, double[,] filterArray, double factor = 1, int bias = 0, bool grayscale = false ) { BitmapData sourceBitmapData = sourceBitmap.LockBits ( new Rectangle (0, 0, sourceBitmap.Width, sourceBitmap.Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb ); byte[] sourceByteArray = new byte[sourceBitmapData.Stride * sourceBitmapData.Height]; byte[] targetByteArray = new byte[sourceBitmapData.Stride * sourceBitmapData.Height]; Marshal.Copy(sourceBitmapData.Scan0, sourceByteArray, 0, sourceByteArray.Length); sourceBitmap.UnlockBits(sourceBitmapData); if(grayscale == true) { float rgb = 0; for(int k = 0; k < sourceByteArray.Length; k += 4) { rgb = sourceByteArray[k ] * 0.11f; rgb += sourceByteArray[k + 1] * 0.59f; rgb += sourceByteArray[k + 2] * 0.3f; sourceByteArray[k ] = (byte )rgb; sourceByteArray[k + 1] = sourceByteArray[k]; sourceByteArray[k + 2] = sourceByteArray[k]; sourceByteArray[k + 3] = 255; } } double blue = 0.0; double green = 0.0; double red = 0.0; int filterWidth = filterArray.GetLength(1); int filterHeight = filterArray.GetLength(0); int filterOffset = (filterWidth-1) / 2; int sourceOffset = 0; int targetOffset = 0; for(int offsetY = filterOffset; offsetY < sourceBitmap.Height - filterOffset; offsetY++) { for(int offsetX = filterOffset; offsetX < sourceBitmap.Width - filterOffset; offsetX++) { blue = 0; green = 0; red = 0; targetOffset = offsetY * sourceBitmapData.Stride + offsetX * 4; for(int filterY = -filterOffset; filterY <= filterOffset; filterY++) { for(int filterX = -filterOffset; filterX <= filterOffset; filterX++) { sourceOffset = targetOffset + (filterX * 4) + (filterY * sourceBitmapData.Stride); blue += (double)(sourceByteArray[sourceOffset ]) * filterArray[filterY + filterOffset, filterX + filterOffset]; green += (double)(sourceByteArray[sourceOffset + 1]) * filterArray[filterY + filterOffset, filterX + filterOffset]; red += (double)(sourceByteArray[sourceOffset + 2]) * filterArray[filterY + filterOffset, filterX + filterOffset]; } } blue = factor * blue + bias; green = factor * green + bias; red = factor * red + bias; if(blue > 255) { blue = 255; } else if(blue < 0) { blue = 0; } if(green > 255) { green = 255; } else if(green < 0) { green = 0; } if(red > 255) { red = 255; } else if(red < 0) { red = 0; } targetByteArray[targetOffset ] = (byte)blue; targetByteArray[targetOffset + 1] = (byte)green; targetByteArray[targetOffset + 2] = (byte)red; targetByteArray[targetOffset + 3] = 255; } } Bitmap targetBitmap = new Bitmap(sourceBitmap.Width, sourceBitmap.Height); BitmapData targetBitmapData = targetBitmap.LockBits ( new Rectangle (0, 0, targetBitmap.Width, targetBitmap.Height), ImageLockMode.WriteOnly, PixelFormat.Format32bppArgb ); Marshal.Copy(targetByteArray, 0, targetBitmapData.Scan0, targetByteArray.Length); targetBitmap.UnlockBits(targetBitmapData); return targetBitmap; } #endregion |