■ Bitmap 클래스에서 중앙값 필터(Median Filter)를 사용하는 방법을 보여준다.
▶ BitmapHelper.cs
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using System; using System.Collections.Generic; using System.Drawing; using System.Drawing.Imaging; using System.Runtime.InteropServices; namespace TestProject { /// <summary> /// 비트맵 헬퍼 /// </summary> public static class BitmapHelper { //////////////////////////////////////////////////////////////////////////////////////////////////// Method ////////////////////////////////////////////////////////////////////////////////////////// Static //////////////////////////////////////////////////////////////////////////////// Public #region 비트맵 로드하기 - LoadBitmap(filePath) /// <summary> /// 비트맵 로드하기 /// </summary> /// <param name="filePath">파일 경로</param> /// <returns>비트맵</returns> public static Bitmap LoadBitmap(string filePath) { using(Bitmap bitmap = new Bitmap(filePath)) { return new Bitmap(bitmap); } } #endregion #region 중앙값 필터 적용하기 - ApplyMedianFilter(sourceBitmap, matrixSize, bias, grayscale) /// <summary> /// 중앙값 필터 적용하기 /// </summary> /// <param name="sourceBitmap">소스 비트맵</param> /// <param name="matrixSize">매트릭스 크기</param> /// <param name="bias">바이어스</param> /// <param name="grayscale">회색조 여부</param> /// <returns>비트맵</returns> public static Bitmap ApplyMedianFilter(Bitmap sourceBitmap, int matrixSize, 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; } } int filterOffset = (matrixSize - 1) / 2; int sourceOffset = 0; int targetOffset = 0; List<int> neighbourPixelList = new List<int>(); byte[] middlePixelArray; for(int offsetY = filterOffset; offsetY < sourceBitmap.Height - filterOffset; offsetY++) { for(int offsetX = filterOffset; offsetX < sourceBitmap.Width - filterOffset; offsetX++) { targetOffset = offsetY * sourceBitmapData.Stride + offsetX * 4; neighbourPixelList.Clear(); for(int filterY = -filterOffset; filterY <= filterOffset; filterY++) { for(int filterX = -filterOffset; filterX <= filterOffset; filterX++) { sourceOffset = targetOffset + (filterX * 4) + (filterY * sourceBitmapData.Stride); neighbourPixelList.Add(BitConverter.ToInt32(sourceByteArray, sourceOffset)); } } neighbourPixelList.Sort(); middlePixelArray = BitConverter.GetBytes(neighbourPixelList[filterOffset]); targetByteArray[targetOffset ] = middlePixelArray[0]; targetByteArray[targetOffset + 1] = middlePixelArray[1]; targetByteArray[targetOffset + 2] = middlePixelArray[2]; targetByteArray[targetOffset + 3] = middlePixelArray[3]; } } 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 } } |
▶ MainForm.cs
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using System.Drawing; using System.Windows.Forms; namespace TestProject { /// <summary> /// 메인 폼 /// </summary> public partial class MainForm : Form { //////////////////////////////////////////////////////////////////////////////////////////////////// Constructor ////////////////////////////////////////////////////////////////////////////////////////// Public #region 생성자 - MainForm() /// <summary> /// 생성자 /// </summary> public MainForm() { InitializeComponent(); Bitmap sourceBitmap = BitmapHelper.LoadBitmap("IMAGE\\sample.jpg"); Bitmap targetBitmap = BitmapHelper.ApplyMedianFilter(sourceBitmap, 3, 0, false); this.pictureBox.SizeMode = PictureBoxSizeMode.Zoom; this.pictureBox.Image = targetBitmap; } #endregion } } |
