- if (!j2k_same) {
-
- if (opt.verbose) {
- cout << "J2K images for " << frame << " differ; checking by pixel\n";
- }
-
- /* Decompress the images to bitmaps */
- opj_image_t* image_A = decompress_j2k (const_cast<uint8_t*> (data_A), size_A, 0);
- opj_image_t* image_B = decompress_j2k (const_cast<uint8_t*> (data_B), size_B, 0);
-
- /* Compare them */
-
- if (image_A->numcomps != image_B->numcomps) {
- notes.push_back ("image component counts for frame " + lexical_cast<string>(frame) + " differ");
- }
-
- vector<int> abs_diffs (image_A->comps[0].w * image_A->comps[0].h * image_A->numcomps);
- int d = 0;
- int max_diff = 0;
-
- for (int c = 0; c < image_A->numcomps; ++c) {
-
- if (image_A->comps[c].w != image_B->comps[c].w || image_A->comps[c].h != image_B->comps[c].h) {
- notes.push_back ("image sizes for frame " + lexical_cast<string>(frame) + " differ");
- }
-
- int const pixels = image_A->comps[c].w * image_A->comps[c].h;
- for (int j = 0; j < pixels; ++j) {
- int const t = abs (image_A->comps[c].data[j] - image_B->comps[c].data[j]);
- abs_diffs[d++] = t;
- max_diff = max (max_diff, t);
- }
- }
-
- uint64_t total = 0;
- for (vector<int>::iterator j = abs_diffs.begin(); j != abs_diffs.end(); ++j) {
- total += *j;
- }
-
- double const mean = double (total) / abs_diffs.size ();
-
- uint64_t total_squared_deviation = 0;
- for (vector<int>::iterator j = abs_diffs.begin(); j != abs_diffs.end(); ++j) {
- total_squared_deviation += pow (*j - mean, 2);
- }
-
- double const std_dev = sqrt (double (total_squared_deviation) / abs_diffs.size());