java - implementing Discrete Wavelet Transformation on android -
i'm writing application applying discrete wavelet transformation on image , inverse class applying algorithm works in java when try convert android platform image dose not appear don't know why here code class , main activity :
wtc using haar class :
import android.graphics.bitmap; /** * @author the-e_000 */ public class haar { private final double w0 = 0.5; private final double w1 = -0.5; private final double s0 = 0.5; private final double s1 = 0.5; /// <summary> /// discrete haar wavelet transform /// </summary> /// public void fwt(double[] data) { double[] temp = new double[data.length]; int h = data.length >> 1; (int = 0; < h; i++) { int k = (i << 1); temp[i] = data[k] * s0 + data[k + 1] * s1; temp[i + h] = data[k] * w0 + data[k + 1] * w1; } (int = 0; < data.length; i++) data[i] = temp[i]; } /// <summary> /// discrete haar wavelet 2d transform /// </summary> /// public void fwt(double[][] data, int iterations) { int rows = data.length; int cols = data[0].length; double[] row = new double[cols]; double[] col = new double[rows]; (int k = 0; k < iterations; k++) { (int = 0; < rows; i++) { (int j = 0; j < row.length; j++) row[j] = data[i][j]; fwt(row); (int j = 0; j < row.length; j++) data[i][j] = row[j]; } (int j = 0; j < cols; j++) { (int = 0; < col.length; i++) col[i] = data[i][j]; fwt(col); (int = 0; < col.length; i++) data[i][j] = col[i]; } } } /// <summary> /// inverse haar wavelet transform /// </summary> /// public void iwt(double[] data) { double[] temp = new double[data.length]; int h = data.length >> 1; (int = 0; < h; i++) { int k = (i << 1); temp[k] = (data[i] * s0 + data[i + h] * w0) / w0; temp[k + 1] = (data[i] * s1 + data[i + h] * w1) / s0; } (int = 0; < data.length; i++) data[i] = temp[i]; } /// <summary> /// inverse haar wavelet 2d transform /// </summary> /// public void iwt(double[][] data, int iterations) { int rows = data.length; int cols = data[0].length; double[] col = new double[rows]; double[] row = new double[cols]; (int l = 0; l < iterations; l++) { (int j = 0; j < cols; j++) { (int = 0; < row.length; i++) col[i] = data[i][j]; iwt(col); (int = 0; < col.length; i++) data[i][j] = col[i]; } (int = 0; < rows; i++) { (int j = 0; j < row.length; j++) row[j] = data[i][j]; iwt(row); (int j = 0; j < row.length; j++) data[i][j] = row[j]; } } } public double scale(double frommin, double frommax, double tomin, double tomax, double x) { if (frommax - frommin == 0) { return 0; } double value = (tomax - tomin) * (x - frommin) / (frommax - frommin) + tomin; if (value > tomax) { value = tomax; } if (value < tomin) { value = tomin; } return value; } public void applyhaartransform(boolean forward, bitmap img) throws exception { int iterations = 1; double[][] red = new double[img.getwidth()][img.getheight()]; double[][] green = new double[img.getwidth()][img.getheight()]; double[][] blue = new double[img.getwidth()][img.getheight()]; int c; (int j = 0; j < img.getheight(); j++) { (int = 0; < img.getwidth(); i++) { c = img.getpixel(i, j); red[i][j] = (double) scale(0, 255, -1, 1, (c >> 16) & 0x000000ff); green[i][j] = (double) scale(0, 255, -1, 1, (c >> 8) & 0x000000ff); blue[i][j] = (double) scale(0, 255, -1, 1, (c) & 0x000000ff); } } if (forward) { fwt(red, iterations); fwt(green, iterations); fwt(blue, iterations); } else { iwt(red, iterations); iwt(green, iterations); iwt(blue, iterations); } (int j = 0; j < img.getheight(); j++) { (int = 0; < img.getwidth(); i++) { int r = (int) scale(-1, 1, 0, 255, red[i][j]);// red component 0...255 int g = (int) scale(-1, 1, 0, 255, green[i][j]);// green component 0...255 int b = (int) scale(-1, 1, 0, 255, blue[i][j]);// blue component 0...255 int col = (r << 16) | (g << 8) | b; img.setpixel(i, j, col); } } } } main activity :
bitmap img = bitmapfactory.decodefile(imgdecodablestring); imageview imgview = (imageview) findviewbyid(r.id.imgview); // take image , add transform haar trans = new haar(); bitmap img2 = null; try { trans.applyhaartransform(true, true, img); } catch(exception e) { toast.maketext(this,e.getmessage(), toast.length_long).show(); } // set image in imageview after decoding string imgview.setimagebitmap(img2);
in code u put null image in imageview:
bitmap img2 = null; and after transformation code
imgview.setimagebitmap(img2); but
try { trans.applyhaartransform(true, true, img); } catch(exception e) { toast.maketext(this,e.getmessage(), toast.length_long).show(); } have no effect on img2 instead u may make method :
public void applyhaartransform(boolean forward, bitmap img) returns image , is
public bitmap applyhaartransform(boolean forward, bitmap img) and before closing parathesis add 1 line of code :
return img; and in try catch code yourcode be:
try { img2=trans.applyhaartransform(true, true, img); } catch(exception e) { toast.maketext(this,e.getmessage(), toast.length_long).show(); }
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