Declarations for an image and associated functions. More...

#include <jwsc/config.h>
#include <stdlib.h>
#include <inttypes.h>
#include "jwsc/base/error.h"
#include "jwsc/matrix/matrix.h"

Include dependency graph for image.h:

Go to the source code of this file.

Data Structures
struct	Pixel_f
	A 3-sample single precision floating point picture element. More...
struct	Image_f
	An image of Pixel_f. More...
Typedefs
typedef struct Pixel_f	Pixel_f
	A 3-sample single precision floating point picture element.
typedef struct Image_f	Image_f
	An image of Pixel_f.
Functions
create_image
Creates an image.
void	create_image_f (Image_f **img_out, uint32_t num_rows, uint32_t num_cols)
	Creates a single precision floating point image.
create_init_image
Creates and initializes an image.
void	create_init_image_f (Image_f **img_out, uint32_t num_rows, uint32_t num_cols, Pixel_f val)
	Creates and initializes a single precision floating point image.
create_zero_image
Creates an image and initializes it with zeros.
void	create_zero_image_f (Image_f **img_out, uint32_t num_rows, uint32_t num_cols)
	Creates a single precision floating point image and initializes it with zeros.
create_random_image
Creates an image and initializes it with random values.
void	create_random_image_f (Image_f **img_out, uint32_t num_rows, uint32_t num_cols, Pixel_f min, Pixel_f max)
	Creates a single precision floating point image and initializes it with random values.
create_image_from_matrices
Creates an image from a three matrices.
Error *	create_image_from_matrices_f (Image_f *img_out, const Matrix_f m_r, const Matrix_f m_g, const Matrix_f m_b)
	Creates a single precision floating point image from three matrices.
create_image_from_matrix
Creates a grayscale image from a matrix.
void	create_image_from_matrix_f (Image_f *img_out, const Matrix_f m)
	Creates a single precision floating point grayscale image from a matrix.
create_matrices_from_image
Creates three matrices from an image.
void	create_matrices_from_image_f (Matrix_f m_r_out, Matrix_f m_g_out, Matrix_f *m_b_out, const Image_f img)
	Creates three single precision floating point matrices from an image.
create_matrix_from_image
Creates an averaged matrix from an image.
void	create_matrix_from_image_f (Matrix_f *m_out, const Image_f img, float r_weight, float g_weight, float b_weight)
	Creates an averaged single precision floating point matrix from an image.
copy_image
Copies an image.
void	copy_image_f (Image_f *img_out, const Image_f img_in)
	Copies a single precision floating point image.
free_image
Frees an image.
void	free_image_f (Image_f *img)
	Frees a single precision floatin point image.

Detailed Description

Declarations for an image and associated functions.

Author:: Joseph Schlecht

License:: Creative Commons BY-NC-SA 3.0

The image holds single precision floating point pixel elements.

Although the image is indexed by row and column, the pixels are allocated as a 1D array in row-major order. So iterating over the pixels can be done inside a single loop.

Definition in file image.h.

Typedef Documentation

typedef struct Pixel_f Pixel_f

A 3-sample single precision floating point picture element.

Sample values range [0,1].

typedef struct Image_f Image_f

An image of Pixel_f.

Function Documentation

void create_image_f	(	Image_f **	img_out,
		uint32_t	num_rows,
		uint32_t	num_cols
	)

Creates a single precision floating point image.

Parameters:

img_out	Result parameter. If *img_out is NULL, an image is allocated; otherwise its space is re-used.
num_rows	Number of rows in the image.
num_cols	Number of columns in the image.

Note:: Dimensions must be > 0.

Definition at line 84 of file image.c.

void create_init_image_f	(	Image_f **	img_out,
		uint32_t	num_rows,
		uint32_t	num_cols,
		Pixel_f	val
	)

Creates and initializes a single precision floating point image.

Parameters:

img_out	Result parameter. If *img_out is NULL, an image is allocated; otherwise its space is re-used.
num_rows	Number of rows in the image.
num_cols	Number of columns in the image.
val	Pixel value to initialize all pixels of the image with.

Note:: Dimensions must be > 0.

Definition at line 145 of file image.c.

void create_zero_image_f	(	Image_f **	img_out,
		uint32_t	num_rows,
		uint32_t	num_cols
	)

Creates a single precision floating point image and initializes it with zeros.

Parameters:

img_out	Result parameter. If *img_out is NULL, an image is allocated; otherwise its space is re-used.
num_rows	Number of rows in the image.
num_cols	Number of columns in the image.

Note:: Dimensions must be > 0.

Definition at line 187 of file image.c.

void create_random_image_f	(	Image_f **	img_out,
		uint32_t	num_rows,
		uint32_t	num_cols,
		Pixel_f	min,
		Pixel_f	max
	)

Creates a single precision floating point image and initializes it with random values.

Calls rand() to generate the random numbers.

Parameters:

img_out	Result parameter. If *img_out is NULL, an image is allocated; otherwise its space is re-used.
num_rows	Number of rows in the image.
num_cols	Number of columns in the image.
min	Minimum random value.
max	Maximum random value.

Note:: Dimensions must be > 0.; Since Pixel_f samples range [0,1], min and max should be in that range as well so a meaningful image is created.

Warning:: Does not check min and max to see if they would cause overflow.

Definition at line 229 of file image.c.

Error* create_image_from_matrices_f	(	Image_f **	img_out,
		const Matrix_f *	m_r,
		const Matrix_f *	m_g,
		const Matrix_f *	m_b
	)

Creates a single precision floating point image from three matrices.

Parameters:

img_out	Result parameter. If *img_out is NULL, an image is allocated; otherwise its space is re-used.
m_r	Matrix to copy into the red samples of the image.
m_g	Matrix to copy into the green samples of the image.
m_b	Matrix to copy into the blue samples of the image.

Returns:

On success, NULL is returned. On error, an Error is returned and *img_out is freed and set to NULL.

ERROR_INV_ARG Matrices do not have the same dimensions.

Definition at line 282 of file image.c.

void create_image_from_matrix_f	(	Image_f **	img_out,
		const Matrix_f *	m
	)

Creates a single precision floating point grayscale image from a matrix.

Parameters:

img_out	Result parameter. If *img_out is NULL, an image is allocated; otherwise its space is re-used.
m	Matrix to copy into the red, green and blue samples of the image.

Definition at line 341 of file image.c.

void create_matrices_from_image_f	(	Matrix_f **	m_r_out,
		Matrix_f **	m_g_out,
		Matrix_f **	m_b_out,
		const Image_f *	img
	)

Creates three single precision floating point matrices from an image.

Parameters:

m_r_out	Result parameter. Red sample matrix. If *m_r_out is NULL, an image is allocated; otherwise its space is re-used.
m_g_out	Result parameter. Green sample matrix. If *m_g_out is NULL, an image is allocated; otherwise its space is re-used.
m_b_out	Result parameter. Blue sample matrix. If *m_b_out is NULL, an image is allocated; otherwise its space is re-used.
img	Image to copy into the matrices.

Definition at line 374 of file image.c.

void create_matrix_from_image_f	(	Matrix_f **	m_out,
		const Image_f *	img,
		float	r_weight,
		float	g_weight,
		float	b_weight
	)

Creates an averaged single precision floating point matrix from an image.

The weights are normalized to sum to one.

The best weights for a human visible grayscale conversion are

   r=0.3   g=0.59   b=0.11

Parameters:

m_out	Result parameter. If *m_out is NULL, a matrix is allocated; otherwise its space is re-used.
img	Image to copy into the matrix.
r_weight	Weight of the red sample.
g_weight	Weight of the green sample.
b_weight	Weight of the blue sample.

Note:: Weights must be non-negative.

Definition at line 438 of file image.c.

void copy_image_f	(	Image_f **	img_out,
		const Image_f *	img_in
	)

Copies a single precision floating point image.

Parameters:

img_out	Result parameter. If *img_out is NULL, an image is allocated; otherwise its space is re-used.
img_in	Image to copy.

Definition at line 493 of file image.c.

void free_image_f ( Image_f * img )

Frees a single precision floatin point image.

Parameters:

img	Image to free.

Definition at line 526 of file image.c.

Data Structures

Typedefs

Functions

Detailed Description

Typedef Documentation

Function Documentation