do not include class IntegralImage.

do not include class IIntegralImage.

srecord noeq MinimalRecognizer(BufferedImage inputImage) {

  replace Channel with int.

  IIntegralImage mainImage;

  static final int grayscale = 3; // channel number for grayscale

  abstract class IIntegralImage {

    // width and height of image

    int w, h;

    abstract double integralValue(int x, int y, Channel channel);

    BufferedImage render() {

      ret imageFromFunction(w, h, (x, y) -> rgbPixel(x, y, x+1, y+1) | fullAlphaMask());

    }

    double getPixel(Rect r, int channel) {

      ret getPixel(r.x, r.y, r.x2(), r.y2(), channel);

    }

    double getPixel(int channel) { ret getPixel(0, 0, w, h, channel); }

    // return value ranges from 0 to 1 (usually)

    double getPixel(int x1, int y1, int x2, int y2, int channel) {

      ret doubleRatio(rectSum(x1, y1, x2, y2, channel), (x2-x1)*(y2-y1)*255.0);

    }

    double rectSum(Rect r, int channel) {

      ret rectSum(r.x, r.y, r.x2(), r.y2(), channel);

    }

    double rectSum(int x1, int y1, int x2, int y2, int channel) {

      double bottomLeft  = integralValue(x1-1, y2-1, channel);

      double bottomRight = integralValue(x2-1, y2-1, channel);

      double topLeft     = integralValue(x1-1, y1-1, channel);

      double topRight    = integralValue(x2-1, y1-1, channel);

      ret bottomRight-topRight-bottomLeft+topLeft;

    }

    int rgbPixel(int x1, int y1, int x2, int y2) {

      int r = iround(clampZeroToOne(getPixel(x1, y1, x2, y2, 0))*255);

      int g = iround(clampZeroToOne(getPixel(x1, y1, x2, y2, 1))*255);

      int b = iround(clampZeroToOne(getPixel(x1, y1, x2, y2, 2))*255);

      ret rgbInt(r, g, b);

    }

    double liveliness(int channel) {

      // optimization (but no change in semantics):

      // if (w <= 1 && h <= 1) ret 0; // liveliness of single pixel is 0

      ret standardDeviation(map(q -> q.getPixel(channel), quadrants()));

    }

    L<IIntegralImage> descentShapes() {

      ret centerPlusQuadrants();

    }

    L<IIntegralImage> centerPlusQuadrants() {

      int midX = w/2, midY = h/2;

      Rect r = rectAround(midX, midY, max(midX/2, 1), max(midY/2, 1));

      ret itemPlusList(clip(r), quadrants());

    }

    L<IIntegralImage> quadrants() {

      if (w <= 1 && h <= 1) null; // let's really not have quadrants of a single pixel

      int midX = w/2, midY = h/2;

      ret mapLL clip(

        rect(0, 0, max(midX, 1), max(midY, 1)),

        rect(midX, 0, w-midX, max(midY, 1)),

        rect(0, midY, max(midX, 1), h-midY),

        rect(midX, midY, w-midX, h-midY)

      );

    }

    IIntegralImage liveliestQuadrant(int channel) {

      ret highestBy(q -> q.liveliness(channel), quadrants());

    }

    Clip clip(Rect r) { ret new Clip(this, r); }

    Clip clip(int x1, int y1, int w, int h) { ret clip(rect(x1, y1, w, h)); }

    Rect positionInImage(IIntegralImage mainImage) {

      if (this == mainImage) ret rect(0, 0, w, h);

      null;

    }

  }

  // virtual clip of an integral image

  class Clip extends IIntegralImage {

    IIntegralImage fullImage;

    int x1, y1;

    *(IIntegralImage *fullImage, Rect r) {

      x1 = r.x; y1 = r.y; w = r.w; h = r.h;

    }

    *(IIntegralImage *fullImage, int *x1, int *y1, int *w, int *h) {}

    public double integralValue(int x, int y, int channel) {

      ret fullImage.integralValue(x+x1, y+y1, channel);

    }

    // don't clip a clip - be smarter than that!

    Clip clip(Rect r) {

      ret new Clip(fullImage, translateRect(r, x1, y1));

    }

    Rect rectInImage() {

      ret rect(x1, y1, w, h);

    }

    Rect positionInImage(IIntegralImage mainImage) {

      try object Rect r = super.positionInImage(mainImage);

      if (fullImage == mainImage) ret rect(x1, y1, w, h);

      null;

    }

    toString { ret rectInImage() + " in " + fullImage; }

  }

  class IntegralImage extends IIntegralImage {

    int[] data;

    *(BufferedImage img) {

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

      if (longMul(w, h) > 8000000) fail("Image too big: " + w + "*" + h);

      int[] pixels = pixelsOfBufferedImage(img);

      data = new int[w*h*3];

      int i = 0, j = 0;

      int[] sum = new[3];

      for y to h: {

        for c to 3: sum[c] = 0;

        for x to w: {

          int rgb = pixels[j++] & 0xFFFFFF;

          for c to 3: {

            data[i] = (sum[c] += rgb >> 16);

            if (y > 0)

              data[i] += data[i-w*3];

            i++;

            rgb = (rgb << 8) & 0xFFFFFF;

          }

        }

      }

    }

    public double integralValue(int x, int y, Channel channel) {

      if (channel == grayscale)

        ret doubleAvg(countIterator(3, c -> integralValue(x, y, c)));

      ret x < 0 || y < 0 ? 0

        : data[(min(y, h-1)*w+min(x, w-1))*3+channel];

    }

  }

  run {

    mainImage = new IntegralImage(inputImage);

    inputImage = null; // save space

    print(liveliness := mainImage.liveliness(grayscale));

    IIntegralImage clip = mainImage;

    clip = applyUntilEqual_goOneBackOnNull(c -> c.liveliestQuadrant(grayscale), clip);

    print(liveliestPoint := clip);

    showImageWithSelection(mainImage.render(), growRect(10, clip.positionInImage(mainImage)));

  }

}