📄 test.c
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#include <stdio.h>
#include <imagelib.h>
#pragma DATA_SECTION(imageBlock,"mydata");
#pragma DATA_SECTION(output,"myout");
short imageBlock[64]={ // A sample of 2-D 8*8 DCT coefficients of the image block.
// Q16.0 format.
32, 15, 6, -1, -1, -2, -1, 1,
7, 3, -1, -4, 0, 2, 1, -1,
-3, -2, 1, 3, -3, -1, 3, -1,
7, 1, -1, 0, 0, 0, 1, -2,
0, 4, 3, -2, -2, 1, -1, 3,
-4, 2, 2, -3, 1, 0, -1, 2,
-2, -2, -1, -2, -2, 3, 1, -1,
3, 0, -2, 1, -1, 0, 2 -1 };
short zigzag[64]={ 0, 1, 5, 6, 14, 15, 27, 28,
2, 4, 7, 13, 16, 26, 29, 42,
3, 8, 12, 17, 25, 30, 41, 43,
9, 11, 18, 24, 31, 40, 44, 53,
10, 19, 23, 32, 39, 45, 52, 54,
20, 22, 33, 38, 46, 51, 55, 60,
21, 34, 37, 47, 50, 56, 59, 61,
35, 36, 48, 49, 57, 58, 62, 63};
short Q_table[64]={ 16, 11, 10, 16, 24, 40, 51, 61,
12, 12, 14, 19, 26, 59, 60, 55,
14, 13, 16, 24, 40, 57, 69, 56,
14, 17, 22, 29, 51, 87, 80, 62,
18, 22, 37, 56, 68, 109, 103, 77,
24, 35, 55, 64, 81, 104, 113, 92,
49, 64, 78, 87, 103, 121, 120, 101,
72, 92, 95, 98, 112, 100, 103, 99};
int output_zigzag[64];
int output[64];
void main()
{
int i;
// for(i=0;i<64;i++) // other test data
//imageBlock[i]=-100;
IMG_jpeg_make_recip_tbl(Q_table);
/* Expected recip-table
2048, 2978, 3276, 2048, 1365, 819, 642, 537,
2730, 2730, 2340, 1724, 1260, 564, 546, 595,
2340, 2520, 2048, 1365, 819, 574, 474, 585,
2340, 1927, 1489, 1129, 642, 376, 409, 528,
1820, 1489, 885, 585, 481, 300, 318, 425,
1365, 936, 595, 512, 404, 315, 289, 356,
668, 512, 420, 376, 318, 270, 273, 324,
455, 356, 344, 334, 292, 327, 318, 330};
*/
IMG_jpeg_quantize(imageBlock,zigzag,Q_table,output_zigzag);
for(i=0;i<64;i++) // output in normal order
output[i]=output_zigzag[zigzag[i]];
/* expected output is
2 1 1 0 0 0 0 0
1 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
*/
}
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