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Add new quantization tables

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New quantization tables tuned for PSNR-HVS are added.
Per-coefficient lambda weights are now derived based on the
quantization table entries.
This commit is contained in:
Frank Bossen
2014-09-30 10:24:52 -04:00
parent 41ebea736d
commit 83d6a8e643
4 changed files with 144 additions and 15 deletions
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13
jcdctmgr.c
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@@ -704,6 +704,8 @@ quantize_trellis(j_compress_ptr cinfo, c_derived_tbl *dctbl, c_derived_tbl *actb
float *accumulated_dc_cost[3];
int *dc_cost_backtrack[3];
JCOEF *dc_candidate[3];
int mode = 1;
float lambda_table[DCTSIZE2];
Ss = cinfo->Ss;
Se = cinfo->Se;
@@ -739,13 +741,20 @@ quantize_trellis(j_compress_ptr cinfo, c_derived_tbl *dctbl, c_derived_tbl *actb
}
}
}
norm = 0.0;
for (i = 1; i < DCTSIZE2; i++) {
norm += qtbl->quantval[i] * qtbl->quantval[i];
}
norm /= 63.0;
lambda_base = 1.0 / norm;
if (mode == 1) {
lambda_base = 1.0;
lambda_tbl = lambda_table;
for (i = 0; i < DCTSIZE2; i++)
lambda_table[i] = 1.0 / (qtbl->quantval[i] * qtbl->quantval[i]);
} else
lambda_base = 1.0 / norm;
for (bi = 0; bi < num_blocks; bi++) {