+ if (imComp.nx() != m_nx && imComp.ny() != m_ny) {
+ sys_error (ERR_WARNING, "Image sizes differ [ImageFile::comparativeStatistics]");
+ return false;
+ }
+ ImageFileArrayConst v = getArray();
+ if (v == NULL || m_nx == 0 || m_ny == 0)
+ return false;
+
+ ImageFileArrayConst vComp = imComp.getArray();
+
+ double myMean = 0.;
+ for (unsigned int ix = 0; ix < m_nx; ix++) {
+ for (unsigned int iy = 0; iy < m_ny; iy++) {
+ myMean += v[ix][iy];
+ }
+ }
+ myMean /= (m_nx * m_ny);
+
+ double sqErrorSum = 0.;
+ double absErrorSum = 0.;
+ double sqDiffFromMeanSum = 0.;
+ double absValueSum = 0.;
+ for (unsigned int ix2 = 0; ix2 < m_nx; ix2++) {
+ for (unsigned int iy = 0; iy < m_ny; iy++) {
+ double diff = v[ix2][iy] - vComp[ix2][iy];
+ sqErrorSum += diff * diff;
+ absErrorSum += fabs(diff);
+ double diffFromMean = v[ix2][iy] - myMean;
+ sqDiffFromMeanSum += diffFromMean * diffFromMean;
+ absValueSum += fabs(v[ix2][iy]);
+ }
+ }
+
+ d = sqrt (sqErrorSum / sqDiffFromMeanSum);
+ r = absErrorSum / absValueSum;
+
+ int hx = m_nx / 2;
+ int hy = m_ny / 2;
+ double eMax = -1;
+ for (int ix3 = 0; ix3 < hx; ix3++) {
+ for (int iy = 0; iy < hy; iy++) {
+ double avgPixel = 0.25 * (v[2*ix3][2*iy] + v[2*ix3+1][2*iy] + v[2*ix3][2*iy+1] + v[2*ix3+1][2*iy+1]);
+ double avgPixelComp = 0.25 * (vComp[2*ix3][2*iy] + vComp[2*ix3+1][2*iy] + vComp[2*ix3][2*iy+1] + vComp[2*ix3+1][2*iy+1]);
+ double error = fabs (avgPixel - avgPixelComp);
+ if (error > eMax)
+ eMax = error;
+ }
+ }
+
+ e = eMax;