dec_jpeg2000.c

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#ifndef USE_JPEG2000
void dummy(void) {}
#else   /* USE_JPEG2000 */
 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "grib2.h"
#include "jasper/jasper.h"
#define JAS_1_700_2
 
int
dec_jpeg2000(char *injpc, g2int bufsize, g2int *outfld)
{
    g2int i, j, k;
    jas_image_t *image = NULL;
    jas_stream_t *jpcstream;
    jas_image_cmpt_t *pcmpt;
    char *opts = NULL;
    jas_matrix_t *data;
 
    /* Create jas_stream_t containing input JPEG200 codestream in
     * memory. */
    jpcstream = jas_stream_memopen(injpc, bufsize);
 
    /* Decode JPEG200 codestream into jas_image_t structure. */
    if (!(image = jpc_decode(jpcstream, opts)))
    {
        printf(" jpc_decode return\n");
        return -3;
    }
 
    pcmpt = image->cmpts_[0];
    /*
      printf(" SAGOUT DECODE:\n");
      printf(" tlx %d \n", image->tlx_);
      printf(" tly %d \n", image->tly_);
      printf(" brx %d \n", image->brx_);
      printf(" bry %d \n", image->bry_);
      printf(" numcmpts %d \n", image->numcmpts_);
      printf(" maxcmpts %d \n", image->maxcmpts_);
      #ifdef JAS_1_500_4
      printf(" colormodel %d \n", image->colormodel_);
      #endif
      #ifdef JAS_1_700_2
      printf(" colorspace %d \n", image->clrspc_);
      #endif
      printf(" inmem %d \n", image->inmem_);
      printf(" COMPONENT:\n");
      printf(" tlx %d \n", pcmpt->tlx_);
      printf(" tly %d \n", pcmpt->tly_);
      printf(" hstep %d \n", pcmpt->hstep_);
      printf(" vstep %d \n", pcmpt->vstep_);
      printf(" width %d \n", pcmpt->width_);
      printf(" height %d \n", pcmpt->height_);
      printf(" prec %d \n", pcmpt->prec_);
      printf(" sgnd %d \n", pcmpt->sgnd_);
      printf(" cps %d \n", pcmpt->cps_);
      #ifdef JAS_1_700_2
      printf(" type %d \n", pcmpt->type_);
      #endif
    */
 
    /* Expecting jpeg2000 image to be grayscale only. No color components. */
    if (image->numcmpts_ != 1)
    {
        printf("dec_jpeg2000: Found color image.  Grayscale expected.\n");
        return (-5);
    }
 
    /* Create a data matrix of grayscale image values decoded from the
     * jpeg2000 codestream. */
    data = jas_matrix_create(jas_image_height(image), jas_image_width(image));
    jas_image_readcmpt(image, 0, 0, 0, jas_image_width(image),
                       jas_image_height(image), data);
 
    /* Copy data matrix to output integer array. */
    k = 0;
    for (i = 0; i < pcmpt->height_; i++)
        for (j = 0; j < pcmpt->width_; j++)
            outfld[k++] = data->rows_[i][j];
 
    /* Clean up JasPer work structures. */
    jas_matrix_destroy(data);
    jas_stream_close(jpcstream);
    jas_image_destroy(image);
 
    return 0;
}
#endif   /* USE_JPEG2000 */