static int ocr_findOutExactHeightOfTaskBar_v1(O... _) {
  int grid = optPar grid(_, 8); // power of 2 is good
  RGBImage screenshot = optParOr screenshot(_, () -> shootScreenRGB());
  int approxH = ocr_findOutApproximateHeightOfTaskBar_v1(paramsPlus(_, +screenshot, +grid));
  RGB col = ocr_findOutApproximateHeightOfTaskBar_v1_dominantColor!;
  int approxY = screenshot.getHeight()-approxH;
  int y1 = approxY-grid/2, y2 = approxY+grid/2;
  RGBImage clip = rgbClip(screenshot, rectFromPoints(0, y1, screenshot.getWidth(), y2));
  L<RGBImage> slices = rgbImageVerticalSlices(1, clip);
  L<Int> dominantColors = map dominant332color(slices);
  //showImage(mergeImagesVertically(map rgbSingleColorCube(map rgbFrom332(dominantColors))));
  int idx = indexOfLastChange(dominantColors);
  if (idx < 0) ret approxH;
  ret screenshot.getHeight()-(y1+idx);
}