smoothHistogram()

in src/ui/Histogram/HistogramUtils.js [40:81]

• 39 lines of code
• 12 McCabe index (conditional complexity)

  smoothHistogram(sigma = 1.2, needNormalize = true) {
    const SIZE_DIV = 60;
    let RAD = Math.floor(this.m_numColors / SIZE_DIV);
    // avoid too large neighbourhood window size
    const SIZE_LARGE = 32;
    if (RAD > SIZE_LARGE) {
      RAD = SIZE_LARGE;
    }
    // console.log(`smoothHistogram. RAD = ${RAD}`);

    const KOEF = 1.0 / (2 * sigma * sigma);
    const newHist = new Array(this.m_numColors);
    let i;
    let maxVal = 0;
    for (i = 0; i < this.m_numColors; i++) {
      let sum = 0;
      let sumW = 0;
      for (let di = -RAD; di <= RAD; di++) {
        const ii = i + di;
        const t = di / RAD;
        const w = Math.exp(-t * t * KOEF);
        if (ii >= 0 && ii < this.m_numColors) {
          sum += this.m_histogram[ii] * w;
          sumW += w;
        }
      }
      sum /= sumW;
      maxVal = sum > maxVal ? sum : maxVal;

      newHist[i] = sum;
    } // for (i)
    // copy back to hist
    if (needNormalize) {
      for (i = 0; i < this.m_numColors; i++) {
        this.m_histogram[i] = newHist[i] / maxVal;
      } // for (i)
    } else {
      for (i = 0; i < this.m_numColors; i++) {
        this.m_histogram[i] = newHist[i];
      } // for (i)
    }
  } // smoothHistogram