imgblock_util.c File Reference

Definitions for image block utility functions. More...

#include <jwsc/config.h>
#include <stdlib.h>
#include <inttypes.h>
#include <math.h>
#include <assert.h>
#include "jwsc/base/error.h"
#include "jwsc/matblock/matblock.h"
#include "jwsc/filter/3d.h"
#include "jwsc/imgblock/imgblock.h"

Include dependency graph for imgblock_util.c:

Go to the source code of this file.

Functions
down_sample_imgblock
Down samples an image block.
Error *	down_sample_imgblock_f (Imgblock_f **img_out, const Imgblock_f *img_in, float img_factor, float row_factor, float col_factor)
	Down samples a single precision image block.

---

Detailed Description

Definitions for image block utility functions.

Author:

Joseph Schlecht

License:

Creative Commons BY-NC-SA 3.0

Definition in file imgblock_util.c.

---

Function Documentation

Error* down_sample_imgblock_f	(	Imgblock_f **	img_out,
		const Imgblock_f *	img_in,
		float	img_factor,
		float	row_factor,
		float	col_factor
	)

Down samples a single precision image block.

Uses a Gaussian smoothing function to down sample.

Parameters:

img_out	Result parameter. If *img_out is NULL, an image block is allocated; otherwise its space is re-used.
img_in	Image to down sample.
img_factor	Percentage of current number of images to down sample the number of images in the image block to, in the range (0,1].
row_factor	Percentage of current number of rows to down sample the number of rows in the image block to, in the range (0,1].
col_factor	Percentage of current number of columns to down sample the number of columns in the image block to, in the range (0,1].

Returns:

On success, NULL is returned. On error, an Error is returned and *img_out is freed and set to NULL (if it is not img_in).

• ERROR_INV_ARG Down sampling row_factor or col_factor are not in (0, 1].

Note:

If *img_out == img_in, then img_in is overwritten.

Definition at line 89 of file imgblock_util.c.