Commit a41acf59 authored by Andrey Filippov's avatar Andrey Filippov
Browse files

implementng mdct/imdct

parent 4ebf5c11

src/main/java/DttRad2.java

+313 −88
Original line number Diff line number Diff line
@@ -28,90 +28,236 @@ 
 */



public class DttRad2 {

	int N = 8;

	double [][][] CII;

	double [][][] CIV;

	double [][] CN1; 

	double [][] SN1; 

//	double [][] C_N1M1; 

//	double [][] S_N1M1; 

	int N = 0;

	double [][][] CII=null;

	double [][][] CIV=null;

	double [][][] SIV=null;

	double [][] CN1=null; 

	double [][] SN1=null; 

	double      COSPI_1_8_SQRT2 = Math.cos(Math.PI/8)*Math.sqrt(2.0);

	double      COSPI_3_8_SQRT2 = Math.cos(3*Math.PI/8)*Math.sqrt(2.0);

	double sqrt2 = Math.sqrt(2.0);

	double sqrt1_2 = 1/sqrt2;

	double [] hwindow = null; // half window

	

	public DttRad2 (int maxN){ // n - maximal

		N=maxN;

		CII = null; // only needed for direct transforms. Assign when first used

		CIV = null; // same

		setup_arrays(maxN); // always setup arrays for fast calculations

	}



		CN1 = new double[ilog2(N)-1][];

		SN1 = new double[ilog2(N)-1][];

//		C_N1M1 = new double[ilog2(N)-1][];

//		S_N1M1 = new double[ilog2(N)-1][];

	public double [] dct_ii(double[] x){

		if (x.length > N){

			N = x.length;

		}

		double [] y=  _dctii_recurs(x);

		double scale = 1.0/Math.sqrt(x.length);

		for (int i = 0; i < y.length ; i++) y[i] *= scale;

		return y;

	}



		for (int t = 0; t<CN1.length; t++) {

			int n1 = 2 << t; // for N==3: 2, 4, 8

			double pi_4n=Math.PI/(8*n1); // n1 = n/2

//			double pi_2n=Math.PI/(4*n1); // n1 = n/2

			CN1[t] = new double[n1];

			SN1[t] = new double[n1];

//			C_N1M1[t] = new double[n1-1];

//			S_N1M1[t] = new double[n1-1];

			for (int k=0; k<n1; k++){

				CN1[t][k] = Math.cos((2*k+1)*pi_4n);

				SN1[t][k] = Math.sin((2*k+1)*pi_4n);

	public double [] dct_iv(double[] x){

		double [] y=  _dctiv_recurs(x);

		double scale = 1.0/Math.sqrt(x.length);

		for (int i = 0; i < y.length ; i++) y[i] *= scale;

		return y;

	}

//			for (int k=1; k<n1; k++){

//				C_N1M1[t][k-1] = Math.cos(k*pi_2n);

//				S_N1M1[t][k-1] = Math.sin(k*pi_2n);

//			}

	

	public double [] dst_iv(double[] x){

		double [] xr= new double[x.length];

		int j= x.length-1;

		for (int i=0; i < x.length;i++) xr[i] = x[j--];		

		double [] y=  _dctiv_recurs(x);

		double scale = 1.0/Math.sqrt(x.length);

		for (int i = 0; i < y.length ; i++) {

			y[i] *= scale;

			scale = -scale; 

		}

		return y;

	}

	

	public double [] mdct_fold (double [] x ) { // x is 2n long

		int n = x.length/2;

		int n1 = n/2;

		int n3 = n+n1;

		double [] x1 = new double [n];

		for (int i=0; i<n1; i++){

			x1[i]=    -hwindow[n1 + i]* x[n3 -1 -i] - hwindow[n1 - i -1] * x[n3     + i]; 

			x1[i+n1]=  hwindow[     i]* x[       i] - hwindow[n  - i -1] * x[n  - 1 - i]; 

		}

		return x1;

	}



	public void setup_CII(int maxN){

		CII = new double[ilog2(N)][][]; // only needed for direct? Assign only when needed?

		for (int t = 0; t<CII.length; t++) {

			int n = 2 << t; // for N==3: 2, 4, 8

//			System.out.println("t="+t+", n="+n);

			CII[t] = new double[n][n];

			double scale = Math.sqrt(2.0/n);

			double ej;

			double pi_2n=Math.PI/(2*n);

			for (int j=0;j<n; j++){

				if (j==0) ej= Math.sqrt(0.5);

				else ej = 1.0;

				for (int k = 0; k<n; k++){

					CII[t][j][k] = scale * ej * Math.cos(j*(2*k+1)*pi_2n);  

	public double [] mdct_unfold (double [] x) { // x is 2n long

		int n = x.length;

		int n1 = n/2;

		int n3 = n+n1;

		double [] x1 = new double [2*n];

		for (int i=0; i<n1; i++){

			x1[i]=           x[n1+i];

			x1[n - i - 1] =  x1[i]; 

			x1[n3 + i]=     -x[i];

			x1[n1 - i - 1] =-x1[i]; 

		}

		return x1;

	}

	

	

	

	public double [] mdct_2d(double [] x){

		return mdct_2d(x, 0, 1 << (ilog2(x.length/4)/2)); 

	}



	public double [] mdct_2d(double [] x, int mode){

		return mdct_2d(x, mode, 1 << (ilog2(x.length/4)/2)); 

	}

	public void setup_CIV(int maxN){

		CIV = new double[ilog2(N)][][];

		for (int t = 0; t<CIV.length; t++) {

			int n = 2 << t; // for N==3: 2, 4, 8

//			System.out.println("t="+t+", n="+n);

			CIV[t] = new double[n][n];

			double scale = Math.sqrt(2.0/n);

			double pi_4n=Math.PI/(4*n);

			for (int j=0;j<n; j++){

				for (int k = 0; k < j; k++){

					CIV[t][j][k] = CIV[t][k][j];  



	public double [] mdct_2d (double [] x, int mode, int n) { // x is 2n*2n long

//		int n = 1 << (ilog2(x.length/4)/2);

		int n2 = 2*n;

		double [] transp = new double [2*n*n];

		double [] y =      new double [n*n];

		double [] line2 = new double[n*2];

		double [] line = new double[n*2];

		// first (horizontal) pass

		for (int i = 0; i < n2; i++){

			System.arraycopy(x, n2*i, line2, 0, n2);

			line = mdct_fold(line2);

			line = ((mode & 1)!=0)? dst_iv(line):dct_iv(line);

			for (int j=0; j < n;j++) transp[j*n2+i] =line[j]; // transpose 

		}

		// second (vertical) pass

		for (int i = 0; i < n2; i++){

			System.arraycopy(transp, n2*i, line2, 0, n2);

			line = mdct_fold(line2);

			line = ((mode & 2)!=0)? dst_iv(line):dct_iv(line);

			System.arraycopy(line, 0, y, n*i, n);

		}

				for (int k = j; k<n; k++){

					CIV[t][j][k] = scale *  Math.cos((2*j+1)*(2*k+1)*pi_4n);

//                    if (t<2) System.out.println("CIV["+t+"]["+j+"]["+k+"]="+CIV[t][j][k]);

		return y;

	}



	public double [] imdct_2d(double [] x){

		return imdct_2d(x, 1 << (ilog2(x.length)/2)); 

	}



	public double [] imdct_2d (double [] x, int n) { // x is n*n long

		int n2 = 2*n;

		double [] transp = new double [2*n*n];

		double [] y =      new double [4*n*n];

		double [] line2 = new double[n*2];

		double [] line = new double[n*2];

		// first (horizontal) pass

		for (int i = 0; i < n2; i++){

			System.arraycopy(x, n*i, line, 0, n);

			line = dct_iv(line);

			line2 = mdct_unfold(line);

			for (int j=0; j < n2;j++) transp[j*n+i] =line2[j]; // transpose 

		}

		// second (vertical) pass

		for (int i = 0; i < n2; i++){

			System.arraycopy(transp, n*i, line, 0, n);

			line = dct_iv(line);

			line2 = mdct_unfold(line);

			System.arraycopy(line2, 0, y, n2*i, n2);

		}

		return y;

	}

	

	public int ilog2(int n){

		int i;

		for (i=0; n>1; n= n >> 1) i++;

		return i;

	

	public double [] dttt_iv(double [] x){

		return dttt_iv(x, 0, 1 << (ilog2(x.length)/2)); 

	}



	public double [] dttt_iv(double [] x, int mode){

		return dttt_iv(x, mode, 1 << (ilog2(x.length)/2)); 

	}

	public double [] dttt_iv(double [] x, int mode, int n){ // mode 0 - dct,dct 1:dst,dct, 2: dct, dst, 3: dst,dst

		double [] y = new double [n*n];

		double [] line = new double[n];

		// first (horizontal) pass

		for (int i = 0; i<n; i++){

			System.arraycopy(x, n*i, line, 0, n);

			line = ((mode & 1)!=0)? dst_iv(line):dct_iv(line);

			for (int j=0; j < n;j++) y[j*n+i] =line[j]; // transpose 

		}

		// second (vertical) pass

		for (int i = 0; i<n; i++){

			System.arraycopy(y, n*i, line, 0, n);

			line = ((mode & 2)!=0)? dst_iv(line):dct_iv(line);

			System.arraycopy(line, 0, y, n*i, n);

		}

		return y;

	}

	

	public void set_window(){

		set_window(0);

	}

	public void set_window(int mode){

		set_window(mode, N);

	}

	public void set_window(int mode, int len){

		hwindow = new double[len];

		double f = Math.PI/(2.0*len);



		if (mode ==0){

			for (int i = 0; i < len; i++ ) hwindow[i] = Math.sin(f*(i+0.5));

		} else { // add more types?

			double s;

			for (int i = 0; i < len; i++ ) {

				s = Math.sin(f*(i+0.5));

				hwindow[i] = Math.sin(Math.PI*s*s);

			}

		}

	}

	// Convert 2nx2n overlapping tile to n*n for dct-iv

	public double [] fold_tile(double [] x) { // x should be 2n*2n

		return fold_tile(x, 1 << (ilog2(x.length/4)/2));

	}

	public double [] fold_tile(double [] x, int n) { // x should be 2n*2n

		double [] y = new double [n*n];

		for (int i = 0; i<y.length;i++) y[i] = 0;

		int n1 = n/2;

		int n2 = 2*n;

		for (int tile_y_v=0; tile_y_v<2; tile_y_v++){     // 2 rows of y tiles

			for (int tile_y_h=0; tile_y_h<2; tile_y_h++){ // 2 columns of y tiles

				int start_y_addr = n*n1*tile_y_v + n1*tile_y_h; //atart address in the aoutput array

				int start_x_tl_addr = (2*n*n) * (1 - tile_y_v) + n * (1 - tile_y_h); // address of the top left corner of a group of 4 tiles 

				for (int tile_x_v=0; tile_x_v<2; tile_x_v++){     // 2 rows of x tiles (contributing to the same y tile)

					for (int tile_x_h=0; tile_x_h<2; tile_x_h++){ // 2 columns of x tiles (contributing to the same y tile)

						int dir_x = ((tile_y_h ^ tile_x_h) !=0)? 1 : -1;

						int dir_y = ((tile_y_v ^ tile_x_v) !=0)? 1 : -1;

						int start_x_addr =  start_x_tl_addr +

								            tile_x_v * n *n + // 2n * n/2

								            tile_x_h * n1 +

								            ((dir_y < 0)?(n1-1)*2*n : 0)+

								            ((dir_x < 0)?(n1-1) : 0);

						int dir_window_vert =  (tile_x_v > 0)? -1 : +1; // same for any tile_y_*

						int dir_window_hor =   (tile_x_h > 0)? -1 : +1;

						int start_window_vert =  (tile_y_v > 0)? ((tile_x_v > 0)? n-1: 0 ):((tile_x_v > 0)? n1-1: n1);

						int start_window_hor =   (tile_y_h > 0)? ((tile_x_h > 0)? n-1: 0 ):((tile_x_h > 0)? n1-1: n1);

						

						for (int i = 0; i < n1; i++){             // n1 rows in each y tile

							for (int j = 0; j < n1; j++){         // n1 columns in each y tile

								y[start_y_addr+ n*i+j] += hwindow[start_window_vert + dir_window_vert * i] *

														  hwindow[start_window_hor +  dir_window_hor * j] *

														  x[start_x_addr + n2 * dir_y * i + dir_x * j];

							}

						}

					}

				}

			}



		}

		return y;

	}



	public double [] unfold_tile(double [] x) { // x should be n*n

		return fold_tile(x, 1 << (ilog2(x.length)/2));

		

	}

	public double [] unfold_tile(double [] x, int n) { // x should be 2n*2n

		double [] y = new double [4*n*n];

		return y;

	}



	

	public double [] dctii_direct(double[] x){

		int n = x.length;
@@ -144,20 +290,112 @@ public class DttRad2 { 
		}

		return y;

	}

	public double [] dctii_recurs(double[] x){

		double [] y=  _dctii_recurs(x);

		double scale = 1.0/Math.sqrt(x.length);

		for (int i = 0; i < y.length ; i++) y[i] *= scale;



	public double [] dstiv_direct(double[] x){

		int n = x.length;

		int t = ilog2(n)-1;

		if (SIV==null){

			setup_SIV(N); // just full size

		}

		double [] y = new double[n];

		for (int i = 0; i<n; i++) {

			y[i] = 0.0;

			for (int j = 0; j< n; j++){

				y[i]+= SIV[t][i][j]*x[j]; 

			}

		}

		return y;

	}

	private void setup_arrays(int maxN){

		if (N >= maxN) return;

		N = maxN;

		int l = ilog2(N)-1;

		CN1 = new double[l][];

		SN1 = new double[l][];

		

	public double [] dctiv_recurs(double[] x){

		double [] y=  _dctiv_recurs(x);

		double scale = 1.0/Math.sqrt(x.length);

		for (int i = 0; i < y.length ; i++) y[i] *= scale;

		return y;

		for (int t = 0; t<CN1.length; t++) {

			int n1 = 2 << t; // for N==3: 2, 4, 8

			double pi_4n=Math.PI/(8*n1); // n1 = n/2

			CN1[t] = new double[n1];

			SN1[t] = new double[n1];

			for (int k=0; k<n1; k++){

				CN1[t][k] = Math.cos((2*k+1)*pi_4n);

				SN1[t][k] = Math.sin((2*k+1)*pi_4n);

			}

		} 

	}

	

	private void setup_CII(int maxN){

		if (maxN > N) setup_arrays(maxN);		

		int l = ilog2(N);

		if (!(CII==null) && (CII.length >= l)) return;

		CII = new double[l][][]; // only needed for direct? Assign only when needed?

		for (int t = 0; t<CII.length; t++) {

			int n = 2 << t; // for N==3: 2, 4, 8

			CII[t] = new double[n][n];

			double scale = Math.sqrt(2.0/n);

			double ej;

			double pi_2n=Math.PI/(2*n);

			for (int j=0;j<n; j++){

				if (j==0) ej= Math.sqrt(0.5);

				else ej = 1.0;

				for (int k = 0; k<n; k++){

					CII[t][j][k] = scale * ej * Math.cos(j*(2*k+1)*pi_2n);  

				}

			}

		}

	}



	private void setup_CIV(int maxN){

		if (maxN > N) setup_arrays(maxN);		

		int l = ilog2(N);

		if (!(CIV==null) && (CIV.length >= l)) return;

		CIV = new double[l][][];

		for (int t = 0; t<CIV.length; t++) {

			int n = 2 << t; // for N==3: 2, 4, 8

			CIV[t] = new double[n][n];

			double scale = Math.sqrt(2.0/n);

			double pi_4n=Math.PI/(4*n);

			for (int j=0;j<n; j++){

				for (int k = 0; k < j; k++){

					CIV[t][j][k] = CIV[t][k][j];  

				}

				for (int k = j; k<n; k++){

					CIV[t][j][k] = scale *  Math.cos((2*j+1)*(2*k+1)*pi_4n);

				}

			}

		}

	}	



	private void setup_SIV(int maxN){

		if (maxN > N) setup_arrays(maxN);		

		int l = ilog2(N);

		if (!(SIV==null) && (SIV.length >= l)) return;

		SIV = new double[l][][];

		for (int t = 0; t<SIV.length; t++) {

			int n = 2 << t; // for N==3: 2, 4, 8

			SIV[t] = new double[n][n];

			double scale = Math.sqrt(2.0/n);

			double pi_4n=Math.PI/(4*n);

			for (int j=0;j<n; j++){

				for (int k = 0; k < j; k++){

					SIV[t][j][k] = SIV[t][k][j];  

				}

				for (int k = j; k<n; k++){

					SIV[t][j][k] = scale *  Math.cos((2*j+1)*(2*k+1)*pi_4n);

				}

			}

		}

	}	

	

	

	private int ilog2(int n){

		int i;

		for (i=0; n>1; n= n >> 1) i++;

		return i;

	}

	



	private double [] _dctii_recurs(double[] x){

		int n = x.length;

		System.out.println("_dctii_recurs: n="+n);
@@ -213,10 +451,6 @@ public class DttRad2 { 
		if (n ==2) {

			double [] y= {COSPI_1_8_SQRT2*x[0] + COSPI_3_8_SQRT2*x[1],

					      COSPI_3_8_SQRT2*x[0] - COSPI_1_8_SQRT2*x[1]};

			for (int j = 0; j< n; j++){

//				System.out.println("_dctiv_recurs(2): y["+j+"]="+y[j]);

			}		

			

			return y;

		}
@@ -237,10 +471,6 @@ public class DttRad2 { 
		double [] w0 = new double [n1];

		double [] w1 = new double [n1];



		for (int j = 0; j< n1; j++){

//			System.out.println("v0["+j+"]="+v0[j]+", v1["+j+"]="+v1[j]);

		}		

		

		w0[0] =     sqrt2 * v0[0];

		w1[n1-1] =     sqrt2 * v1[0];

		for (int j = 0; j< n1; j++){
@@ -248,17 +478,12 @@ public class DttRad2 { 
			if (j > 0)	    w0[j] = v0[j]   - sgn * v1[n1 - j]; 

			if (j < (n1-1))	w1[j] = v0[j+1] - sgn * v1[n1 - j -1]; 

		}		

		for (int j = 0; j< n1; j++){

//			System.out.println("w0["+j+"]="+w0[j]+", w1["+j+"]="+w1[j]);

		}		



		double [] y = new double[n];

		for (int j = 0; j< n1; j++){

			y[2*j] =     w0[j];

			y[2*j+1] =   w1[j];

		}

		for (int j = 0; j< n; j++){

//			System.out.println("y["+j+"]="+y[j]);

		}		

		return y;

	}

}

src/main/java/Eyesis_Correction.java

+2 −2
Original line number Diff line number Diff line
@@ -2517,8 +2517,8 @@ private Panel panel1,panel2,panel3,panel4,panel5,panel5a, panel6,panel7,panelPos 
    	x[1] = 1.0;

    	y=   dtt.dctiv_direct(x);

    	xr=  dtt.dctiv_direct(y);

    	y1=  dtt.dctiv_recurs(x);

    	xr1= dtt.dctiv_recurs(y1);

    	y1=  dtt.dct_iv(x);

    	xr1= dtt.dct_iv(y1);

    	

    	

        PlotWindow.noGridLines = false; // draw grid lines