!752

static BWImage img;

static ImageSurface is2;

static float threshold = 0.9f;

p {

  img = loadBWImage("#1005702");

  update();

}

svoid update() {

  float[] f = columnBrightnesses(img);

  //quickShowZoomedImage(img.toRGB());

  //showZoomedImage(brightnessesAsImage(f).toRGB());

  L<Streak> streaks = makeStreaks(f, threshold);

  //printStruct(f);

  //printStruct(streaks);

  print("Threshold: " + threshold + ", streaks: " + l(streaks));

  RGBImage vis = visualizeStreaks(img, streaks).toRGB();

  if (is2 == null) {

    is2 = showZoomedImage(vis);

    addToWindowAndPack(is2, liveSlider(threshold/10000f*9999f, voidfunc(float x) {

      threshold = x*10000f/9999f;

      update();

    }));

  } else

    is2.setImage(vis);

}

// f: voidfunc(float)

static JSlider liveSlider(float def, final O f) {

  final int max = 9999;

  final JSlider slider = new JSlider(0, max, iround(def*max));

  slider.addChangeListener(new ChangeListener {

    int lastValue = slider.getValue();

    public void stateChanged(ChangeEvent e) {

      int value = slider.getValue();

      if (value != lastValue) {

        lastValue = value;

        pcallF(f, value/(float) max);

      }

    }

  });

  ret slider;

}

sclass Streak {

  int from, to; // to = exclusive

  *() {}

  *(int *from, int *to) {}

}

static L<Streak> makeStreaks(float[] f, float threshold) {

  new L<Streak> l;

  int j = -1;

  for (int i = 0; i < l(f); i++)

    if (f[i] < threshold) { // start / continue streak

      if (j < 0) j = i; 

    } else {

      if (j >= 0) { // end streak

        l.add(new Streak(j, i));

        j = -1;

      }

    }

  if (j >= 0)

    l.add(new Streak(j, l(f)));

  ret l;

}

static float[] columnBrightnesses(BWImage img) {

  int w = img.getWidth(), h = img.getHeight();

  float[] f = new float[w];

  for x to w:

    f[x] = (float) img.clip(x, 0, 1, h).averageBrightness();

  ret f;

}

static BWImage brightnessesAsImage(float[] f) {

  int w = f.length, h = 20;

  BWImage img = new BWImage(w, h);

  for y to h: for x to w: img.setPixel(x, y, f[x]);

  ret img;

}

static float[] streaksToFloats(int w, L<Streak> l) {

  float[] f = new float[w];

  for (Streak s : l)

    for (int i = s.from; i < s.to; i++)

      f[i] = 1f;

  ret f;

}

static BWImage visualizeStreaks(BWImage img, L<Streak> streaks) {

  float gapColor = 0.5f;

  int w = img.getWidth(), h = img.getHeight();

  BWImage im = new BWImage(w, h*2, gapColor);

  float[] f = streaksToFloats(w, streaks);

  for x to w:

    copyBWImage(img, x, 0, im, x, (int) (f[x]*h), 1, h);

  // auto-crop characters  

  for (Streak s : streaks) {

    Rect r = autoCropOfBWImage(im, new Rect(s.from, h, s.to-s.from, h));

    darkenBWImagePart(im, r);

  }

  ret im;

}