Portable graymap format (PGM) parser - Definition.
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#include "pgm.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
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static int | remove_line (FILE *f) |
| Remove all characters to the next new-line. More...
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static int | remove_blanks (FILE *f) |
| Remove white-spaces and comments. More...
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vl_size | vl_pgm_get_npixels (VlPgmImage const *im) |
| Get PGM image number of pixels. More...
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vl_size | vl_pgm_get_bpp (VlPgmImage const *im) |
| Get PGM image bytes per pixel. More...
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int | vl_pgm_extract_head (FILE *f, VlPgmImage *im) |
| Extract PGM header from stream. More...
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int | vl_pgm_extract_data (FILE *f, VlPgmImage const *im, void *data) |
| Extract PGM data from stream. More...
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int | vl_pgm_insert (FILE *f, VlPgmImage const *im, void const *data) |
| Insert a PGM image into a stream. More...
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int | vl_pgm_read_new (char const *name, VlPgmImage *im, vl_uint8 **data) |
| Read a PGM file. More...
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int | vl_pgm_read_new_f (char const *name, VlPgmImage *im, float **data) |
| Read floats from a PGM file. More...
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int | vl_pgm_write (char const *name, vl_uint8 const *data, int width, int height) |
| Write bytes to a PGM file. More...
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int | vl_pgm_write_f (char const *name, float const *data, int width, int height) |
| Write floats to PGM file. More...
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◆ remove_blanks()
static int remove_blanks |
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FILE * |
f | ) |
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static |
- Parameters
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- Returns
- number of characters removed.
◆ remove_line()
static int remove_line |
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FILE * |
f | ) |
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static |
- Parameters
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- Returns
- number of characters removed.
◆ vl_pgm_extract_data()
int vl_pgm_extract_data |
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FILE * |
f, |
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VlPgmImage const * |
im, |
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void * |
data |
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- Parameters
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f | input file. |
im | PGM image descriptor. |
data | data buffer to fill. |
- Returns
- error code.
The function extracts from the file f the data section of an image encoded in PGM format. The function fills the buffer data according. The buffer data should be vl_pgm_get_npixels() by vl_pgm_get_bpp() bytes large.
◆ vl_pgm_extract_head()
int vl_pgm_extract_head |
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FILE * |
f, |
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VlPgmImage * |
im |
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) |
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- Parameters
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f | input file. |
im | image structure to fill. |
- Returns
- error code.
The function extracts from the file f the meta-data section of an image encoded in PGM format. The function fills the structure VlPgmImage accordingly.
The error may be either VL_ERR_PGM_INV_HEAD or VL_ERR_PGM_INV_META depending whether the error occurred in decoding the header or meta section of the PGM file.
◆ vl_pgm_get_bpp()
- Parameters
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- Returns
- number of bytes per pixel.
The function returns the number of bytes for each pixel of the PGM image im.
◆ vl_pgm_get_npixels()
- Parameters
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- Returns
- number of pixels of the image.
The functions returns the number of pixels of the PGM image im.
To calculate the image data size in bytes, this value must be multiplied by the number of byte per pixels (see vl_pgm_get_bpp()).
◆ vl_pgm_insert()
int vl_pgm_insert |
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FILE * |
f, |
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VlPgmImage const * |
im, |
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void const * |
data |
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- Parameters
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f | output file. |
im | PGM image meta-data. |
data | image data. |
- Returns
- error code.
◆ vl_pgm_read_new()
- Parameters
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name | file name. |
im | a pointer to the PGM image structure to fill. |
data | a pointer to the pointer to the allocated buffer. |
- Returns
- error code.
The function reads a PGM image from file name and initializes the structure im and the buffer data accordingly.
The ownership of the buffer data is transfered to the caller. data should be freed by means of vl_free().
- Bug:
- Only PGM files with 1 BPP are supported.
◆ vl_pgm_read_new_f()
int vl_pgm_read_new_f |
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char const * |
name, |
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VlPgmImage * |
im, |
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float ** |
data |
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) |
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- Parameters
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name | file name. |
im | a pointer to the PGM image structure to fill. |
data | a pointer to the pointer to the allocated buffer. |
- Returns
- error code.
The function reads a PGM image from file name and initializes the structure im and the buffer data accordingly. The buffer data is an array of floats in the range [0, 1].
The ownership of the buffer data is transfered to the caller. data should be freed by means of vl_free().
- Bug:
- Only PGM files with 1 BPP are supported.
◆ vl_pgm_write()
int vl_pgm_write |
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char const * |
name, |
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vl_uint8 const * |
data, |
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int |
width, |
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int |
height |
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) |
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- Parameters
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name | file name. |
data | data to write. |
width | width of the image. |
height | height of the image. |
- Returns
- error code.
The function dumps the image data to the PGM file of the specified name. This is an helper function simplifying the usage of vl_pgm_insert().
◆ vl_pgm_write_f()
int vl_pgm_write_f |
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char const * |
name, |
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float const * |
data, |
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int |
width, |
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int |
height |
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- Parameters
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name | file name. |
data | data to write. |
width | width of the image. |
height | height of the image. |
- Returns
- error code.
The function dumps the image data to the PGM file of the specified name. The data is re-scaled to fit in the range 0-255. This is an helper function simplifying the usage of vl_pgm_insert().