hdf5/hl/examples/ex_image2.c

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by The HDF Group.                                               *
 * Copyright by the Board of Trustees of the University of Illinois.         *
 * All rights reserved.                                                      *
 *                                                                           *
 * This file is part of HDF5.  The full HDF5 copyright notice, including     *
 * terms governing use, modification, and redistribution, is contained in    *
 * the COPYING file, which can be found at the root of the source code       *
 * distribution tree, or in https://www.hdfgroup.org/licenses.               *
 * If you do not have access to either file, you may request a copy from     *
 * help@hdfgroup.org.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

#include "hdf5.h"
#include "hdf5_hl.h"
#include <stdlib.h>
#include <string.h>

#define DATA_FILE1  "image8.txt"
#define DATA_FILE2  "image24pixel.txt"
#define IMAGE1_NAME "image8bit"
#define IMAGE2_NAME "image24bitpixel"
#define PAL_NAME    "palette"
#define PAL_ENTRIES 256

static int     read_data(const char *file_name, hsize_t *width, hsize_t *height);
unsigned char *gbuf = NULL; /* global buffer for image data */

int
main(void)
{
    hid_t         file_id;                        /* HDF5 file identifier */
    hsize_t       width;                          /* width of image */
    hsize_t       height;                         /* height of image */
    unsigned char pal[PAL_ENTRIES * 3];           /* palette array */
    hsize_t       pal_dims[2] = {PAL_ENTRIES, 3}; /* palette dimensions */
    herr_t        i, n;

    /* create a new HDF5 file using default properties. */
    file_id = H5Fcreate("ex_image2.h5", H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);

    /* read first data file */
    if (read_data(DATA_FILE1, &width, &height) < 0)
        goto out;

    /* make the image */
    H5IMmake_image_8bit(file_id, IMAGE1_NAME, width, height, gbuf);
    if (gbuf) {
        free(gbuf);
        gbuf = NULL;
    }

    /*-------------------------------------------------------------------------
     * define a palette, blue to red tones
     *-------------------------------------------------------------------------
     */
    for (i = 0, n = 0; i < PAL_ENTRIES * 3; i += 3, n++) {
        pal[i]     = n;       /* red */
        pal[i + 1] = 0;       /* green */
        pal[i + 2] = 255 - n; /* blue */
    }

    /* make a palette */
    H5IMmake_palette(file_id, PAL_NAME, pal_dims, pal);

    /* attach the palette to the image */
    H5IMlink_palette(file_id, IMAGE1_NAME, PAL_NAME);

    /*-------------------------------------------------------------------------
     * True color image example with pixel interlace
     *-------------------------------------------------------------------------
     */

    /* read second data file */
    if (read_data(DATA_FILE2, &width, &height) < 0)
        goto out;

    /* make dataset */
    H5IMmake_image_24bit(file_id, IMAGE2_NAME, width, height, "INTERLACE_PIXEL", gbuf);

    /* close the file. */
    H5Fclose(file_id);

    if (gbuf) {
        free(gbuf);
        gbuf = NULL;
    }

    return 0;

out:
    printf("Error on return function...Exiting\n");

    if (gbuf) {
        free(gbuf);
        gbuf = NULL;
    }

    return 1;
}

/*-------------------------------------------------------------------------
 * read_data
 * utility function to read ASCII image data
 * the files have a header of the type
 *
 *   components
 *   n
 *   height
 *   n
 *   width
 *   n
 *
 * followed by the image data
 *
 *-------------------------------------------------------------------------
 */

static int
read_data(const char *fname, /*IN*/
          hsize_t *   width, /*OUT*/
          hsize_t *   height /*OUT*/)
{
    int   i, n;
    int   color_planes;
    char  str[20];
    FILE *f;
    int   w, h;
    char *srcdir         = getenv("srcdir"); /* the source directory */
    char  data_file[512] = "";               /* buffer to hold name of existing data file */

    /*-------------------------------------------------------------------------
     * compose the name of the file to open, using "srcdir", if appropriate
     *-------------------------------------------------------------------------
     */
    strcpy(data_file, "");
    if (srcdir) {
        strcpy(data_file, srcdir);
        strcat(data_file, "/");
    }
    strcat(data_file, fname);

    /*-------------------------------------------------------------------------
     * read
     *-------------------------------------------------------------------------
     */

    f = fopen(data_file, "r");
    if (f == NULL) {
        printf("Could not open file %s. Try set $srcdir \n", data_file);
        return -1;
    }

    fscanf(f, "%s", str);
    fscanf(f, "%d", &color_planes);
    fscanf(f, "%s", str);
    fscanf(f, "%d", &h);
    fscanf(f, "%s", str);
    fscanf(f, "%d", &w);

    *width  = (hsize_t)w;
    *height = (hsize_t)h;

    if (gbuf) {
        free(gbuf);
        gbuf = NULL;
    }

    gbuf = (unsigned char *)malloc(w * h * color_planes * sizeof(unsigned char));

    for (i = 0; i < h * w * color_planes; i++) {
        fscanf(f, "%d", &n);
        gbuf[i] = (unsigned char)n;
    }
    fclose(f);

    return 1;
}