주파수 영역처리 C#소스 코드(이산 코사인 변환)

주파수 영역처리 C#소스 코드(이산 코사인 변환)

1. [주파수_이산코사인변환(DCT)] 메뉴를 더블클릭한 후 private void 주파수이산코사인변환DCTToolStripMenuItem_Click() 함수를 추가한다.
   
   private void 주파수이산코사인변환DCTToolStripMenuItem_Click(object sender, EventArgs e) { Bitmap bmp = f_OpenBitmapFile(); if (bmp == null) return; byte[] data = f_getDataFromImage(bmp); ///////// Start Image Processing //////////////// if (bmp.PixelFormat != PixelFormat.Format8bppIndexed) { MessageBox.Show("8bit 색상 모델만 실행 가능합니다."); return; } byte[] newdata = f_DCT_Original(data, bmp.Width, bmp.Height); ///////// End Image Processing //////////////// Bitmap bmpResult = f_makeImageFromData(bmp.Width, bmp.Height, bmp.PixelFormat, newdata); f_drawImage(bmp, bmpResult); }

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   private void 주파수이산코사인변환DCTToolStripMenuItem_Click(object sender, EventArgs e) { Bitmap bmp = f_OpenBitmapFile(); if (bmp == null) return;   byte[] data = f_getDataFromImage(bmp);   ///////// Start Image Processing //////////////// if (bmp.PixelFormat != PixelFormat.Format8bppIndexed) { MessageBox.Show("8bit 색상 모델만 실행 가능합니다."); return; }   byte[] newdata = f_DCT_Original(data, bmp.Width, bmp.Height); ///////// End Image Processing ////////////////   Bitmap bmpResult = f_makeImageFromData(bmp.Width, bmp.Height, bmp.PixelFormat, newdata); f_drawImage(bmp, bmpResult); }

   
    
2. f_DCT_Original() 함수를 생성한다.
   순수 DCT 변환 함수
3. private byte[] f_DCT_Original(byte[] inputImg, int width, int height) { double[] dct = new double[inputImg.Length]; for (int v = 0; v < height; v++) { for (int u = 0; u < width; u++) { dct[v * width + u] = 0.0; for (int y = 0; y < height; y++) { for (int x = 0; x < width; x++) { dct[v * width + u] += inputImg[y * width + x] * Math.Cos(((2.0 * x + 1.0) * u * Math.PI) / (2.0 * width)) * Math.Cos(((2.0 * y + 1.0) * v * Math.PI) / (2.0 * height)); } } dct[v * width + u] *= 2.0 / Math.Sqrt((double)(width * height)); if (u == 0) dct[v * width + u] *= 1.0 / Math.Sqrt(2.0); if (v == 0) dct[v * width + u] *= 1.0 / Math.Sqrt(2.0); } } byte[] resultImg = new byte[inputImg.Length]; for (int y = 0; y < height; y++) { for (int x = 0; x < width; x++) { int value = (int)(30 * Math.Log(1.0 + dct[y * width + x])); if (value < 0) value = 0; if (value > 255) value = 255; resultImg[y * width + x] = (byte)value; } } return resultImg; }

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   private byte[] f_DCT_Original(byte[] inputImg, int width, int height) { double[] dct = new double[inputImg.Length]; for (int v = 0; v < height; v++) { for (int u = 0; u < width; u++) { dct[v * width + u] = 0.0; for (int y = 0; y < height; y++) { for (int x = 0; x < width; x++) { dct[v * width + u] += inputImg[y * width + x] * Math.Cos(((2.0 * x + 1.0) * u * Math.PI) / (2.0 * width)) * Math.Cos(((2.0 * y + 1.0) * v * Math.PI) / (2.0 * height));   } } dct[v * width + u] *= 2.0 / Math.Sqrt((double)(width * height)); if (u == 0) dct[v * width + u] *= 1.0 / Math.Sqrt(2.0); if (v == 0) dct[v * width + u] *= 1.0 / Math.Sqrt(2.0); } }   byte[] resultImg = new byte[inputImg.Length]; for (int y = 0; y < height; y++) { for (int x = 0; x < width; x++) { int value = (int)(30 * Math.Log(1.0 + dct[y * width + x])); if (value < 0) value = 0; if (value > 255) value = 255; resultImg[y * width + x] = (byte)value; } }     return resultImg; }

   
    
4. [주파수_fastDCT] 메뉴를 더블클릭한 후 private void 주파수fastDCTToolStripMenuItem_Click() 함수를 추가한다.
   
   private void 주파수fastDCTToolStripMenuItem_Click(object sender, EventArgs e) { Bitmap bmp = f_OpenBitmapFile(); if (bmp == null) return; byte[] data = f_getDataFromImage(bmp); ////////////////// Start if (bmp.PixelFormat != PixelFormat.Format8bppIndexed) { MessageBox.Show("8bit 색상 모델만 실행 가능합니다."); return; } double[] dct = f_DCT_Fast(data, bmp.Width, bmp.Height); byte[] newdata = f_DCT_toImage(dct, bmp.Width, bmp.Height); ////////////////// End Bitmap bmpResult = f_makeImageFromData(bmp.Width, bmp.Height, newdata); f_drawImage(bmp, bmpResult); }

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   private void 주파수fastDCTToolStripMenuItem_Click(object sender, EventArgs e) { Bitmap bmp = f_OpenBitmapFile(); if (bmp == null) return;   byte[] data = f_getDataFromImage(bmp); ////////////////// Start if (bmp.PixelFormat != PixelFormat.Format8bppIndexed) { MessageBox.Show("8bit 색상 모델만 실행 가능합니다."); return; }   double[] dct = f_DCT_Fast(data, bmp.Width, bmp.Height); byte[] newdata = f_DCT_toImage(dct, bmp.Width, bmp.Height); ////////////////// End Bitmap bmpResult = f_makeImageFromData(bmp.Width, bmp.Height, newdata); f_drawImage(bmp, bmpResult); }

   
    
5. f_DCT_1D() 함수를 생성한다.1차원 DCT 변환 함수 생성
   
   private void f_DCT_1D(double[] in1, double[] out1, int count) { for (int u = 0; u < count; u++) { double z = 0; for (int x = 0; x < count; x++) { z += in1[x] * Math.Cos(Math.PI * u * (2 * x + 1) / (2 * count)); } if (u == 0) z = z * (1.0 / Math.Sqrt(2.0)); out1[u] = z * Math.Sqrt(2.0 / count); } }

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   private void f_DCT_1D(double[] in1, double[] out1, int count) { for (int u = 0; u < count; u++) { double z = 0; for (int x = 0; x < count; x++) { z += in1[x] * Math.Cos(Math.PI * u * (2 * x + 1) / (2 * count)); } if (u == 0) z = z * (1.0 / Math.Sqrt(2.0)); out1[u] = z * Math.Sqrt(2.0 / count); } }

   
    
6. f_DCT_2D() 함수를 생성한다.
   2차원 DCT 변환 함수 생성
   
   private double[] f_DCT_Fast(byte[] data, int width, int height) { double[] dct = new double[data.Length]; double[] in1 = new double[height]; double[] out1 = new double[width]; for (int y = 0; y < height; y++) { for (int x = 0; x < width; x++) { in1[x] = data[y * width + x]; } f_DCT_1D(in1, out1, width); for (int x = 0; x < width; x++) { dct[y * width + x] = out1[x]; } } double[] in2 = new double[width]; double[] out2 = new double[height]; for (int x = 0; x < width; x++) { for (int y = 0; y < height; y++) { in2[y] = dct[y * width + x]; } f_DCT_1D(in2, out2, height); for (int y = 0; y < height; y++) { dct[y * width + x] = out2[y]; } } return dct; }

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   private double[] f_DCT_Fast(byte[] data, int width, int height) { double[] dct = new double[data.Length];   double[] in1 = new double[height]; double[] out1 = new double[width];   for (int y = 0; y < height; y++) { for (int x = 0; x < width; x++) { in1[x] = data[y * width + x]; } f_DCT_1D(in1, out1, width); for (int x = 0; x < width; x++) { dct[y * width + x] = out1[x]; } }     double[] in2 = new double[width]; double[] out2 = new double[height];   for (int x = 0; x < width; x++) { for (int y = 0; y < height; y++) { in2[y] = dct[y * width + x]; } f_DCT_1D(in2, out2, height); for (int y = 0; y < height; y++) { dct[y * width + x] = out2[y]; } }   return dct; }

   
    
7. f_DCT_toImage() 함수를 생성한다.
   fastDCT 변환 후 결과를 2차원 영상으로 변환하는 함수
   
   private byte[] f_DCT_toImage(double[] dct, int width, int height) { byte[] newdata = new byte[dct.Length]; for (int y = 0; y < height; y++) { for (int x = 0; x < width; x++) { int value = (int)(30 * Math.Log(1.0 + dct[y * width + x])); if (value < 0) value = 0; if (value > 255) value = 255; newdata[y * width + x] = (byte)value; } } return newdata; }

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   private byte[] f_DCT_toImage(double[] dct, int width, int height) { byte[] newdata = new byte[dct.Length];   for (int y = 0; y < height; y++) { for (int x = 0; x < width; x++) { int value = (int)(30 * Math.Log(1.0 + dct[y * width + x])); if (value < 0) value = 0; if (value > 255) value = 255; newdata[y * width + x] = (byte)value; } }   return newdata; }

   
    
8. [주파수_fastIDCT] 메뉴를 더블클릭한 후 private void 주파수fastIDCTToolStripMenuItem_Click() 함수를 추가한다.
   
   private void 주파수fastIDCTToolStripMenuItem_Click(object sender, EventArgs e) { Bitmap bmp = f_OpenBitmapFile(); if (bmp == null) return; byte[] data = f_getDataFromImage(bmp); ////////////////// Start if (bmp.PixelFormat != PixelFormat.Format8bppIndexed) { MessageBox.Show("8bit 색상 모델만 실행 가능합니다."); return; } double[] dct = f_DCT_Fast(data, bmp.Width, bmp.Height); double[] idct = f_IDCT_Fast(dct, bmp.Width, bmp.Height); byte[] newdata = f_IDCT_toImage(idct, bmp.Width, bmp.Height); ////////////////// End Bitmap bmpResult = f_makeImageFromData(bmp.Width, bmp.Height, newdata); f_drawImage(bmp, bmpResult); }

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   private void 주파수fastIDCTToolStripMenuItem_Click(object sender, EventArgs e) { Bitmap bmp = f_OpenBitmapFile(); if (bmp == null) return;   byte[] data = f_getDataFromImage(bmp); ////////////////// Start if (bmp.PixelFormat != PixelFormat.Format8bppIndexed) { MessageBox.Show("8bit 색상 모델만 실행 가능합니다."); return; } double[] dct = f_DCT_Fast(data, bmp.Width, bmp.Height); double[] idct = f_IDCT_Fast(dct, bmp.Width, bmp.Height); byte[] newdata = f_IDCT_toImage(idct, bmp.Width, bmp.Height); ////////////////// End Bitmap bmpResult = f_makeImageFromData(bmp.Width, bmp.Height, newdata); f_drawImage(bmp, bmpResult); }

   
    
9. f_IDCT_1D() 함수를 생성한다.1차원 DCT 역변환 함수
   
   void f_IDCT_1D(double[] in1, double[] out1, int count) { double cv; for (int x = 0; x < count; x++) { double z = 0; for (int u = 0; u < count; u++) { if (u == 0) cv = 1.0 / Math.Sqrt(2.0); else cv = 1.0; z += in1[u] * cv * Math.Cos(Math.PI * u * (2 * x + 1) / (2 * count)); } out1[x] = z * Math.Sqrt(2.0 / count); } }

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   void f_IDCT_1D(double[] in1, double[] out1, int count) { double cv; for (int x = 0; x < count; x++) { double z = 0; for (int u = 0; u < count; u++) { if (u == 0) cv = 1.0 / Math.Sqrt(2.0); else cv = 1.0; z += in1[u] * cv * Math.Cos(Math.PI * u * (2 * x + 1) / (2 * count)); } out1[x] = z * Math.Sqrt(2.0 / count); } }

   
    
10. f_IDCT_Fast() 함수를 생성한다.
    2차원 DCT 역변환 함수
    
    private double[] f_IDCT_Fast(double[] dct, int width, int height) { double[] idct = new double[dct.Length]; double[] in1 = new double[height]; double[] out1 = new double[width]; for (int y = 0; y < height; y++) { for (int x = 0; x < width; x++) { in1[x] = dct[y * width + x]; } f_IDCT_1D(in1, out1, width); for (int x = 0; x < width; x++) { idct[y * width + x] = out1[x]; } } double[] in2 = new double[width]; double[] out2 = new double[height]; for (int x = 0; x < width; x++) { for (int y = 0; y < height; y++) { in2[y] = idct[y * width + x]; } f_IDCT_1D(in2, out2, height); for (int y = 0; y < height; y++) { idct[y * width + x] = out2[y]; } } return idct; }

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    private double[] f_IDCT_Fast(double[] dct, int width, int height) { double[] idct = new double[dct.Length];   double[] in1 = new double[height]; double[] out1 = new double[width];   for (int y = 0; y < height; y++) { for (int x = 0; x < width; x++) { in1[x] = dct[y * width + x]; } f_IDCT_1D(in1, out1, width); for (int x = 0; x < width; x++) { idct[y * width + x] = out1[x]; } }     double[] in2 = new double[width]; double[] out2 = new double[height];   for (int x = 0; x < width; x++) { for (int y = 0; y < height; y++) { in2[y] = idct[y * width + x]; } f_IDCT_1D(in2, out2, height); for (int y = 0; y < height; y++) { idct[y * width + x] = out2[y]; } }   return idct; }

    
     
11. f_IDCT_toImage() 함수를 생성한다.
    fastIDCT 변환 후 결과를 2차원 영상으로 변환하는 함수
    
    private byte[] f_IDCT_toImage(double[] idct, int width, int height) { byte[] newdata = new byte[idct.Length]; for (int y = 0; y < height; y++) { for (int x = 0; x < width; x++) { newdata[y * width + x] = (byte)idct[y*width+x]; } } return newdata; }

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    private byte[] f_IDCT_toImage(double[] idct, int width, int height) { byte[] newdata = new byte[idct.Length];   for (int y = 0; y < height; y++) { for (int x = 0; x < width; x++) { newdata[y * width + x] = (byte)idct[y*width+x]; } }   return newdata; }