include/ssim.h File Reference

#include "convolve.h"

Go to the source code of this file.

Data Structures
struct	_ssim_int
struct	_map_reduce
Defines
#define	GAUSSIAN_LEN   11
#define	SQUARE_LEN   8
Typedefs
typedef int(*	_map )(const struct _ssim_int *, void *)
typedef float(*	_reduce )(int, int, void *)
Functions
float	_iqa_ssim (float *ref, float *cmp, int w, int h, const struct _kernel *k, const struct _map_reduce *mr, const struct iqa_ssim_args *args)
Variables
static const float	g_gaussian_window [GAUSSIAN_LEN][GAUSSIAN_LEN]
static const float	g_square_window [SQUARE_LEN][SQUARE_LEN]

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Define Documentation

#define GAUSSIAN_LEN   11

Definition at line 44 of file ssim.h.

#define SQUARE_LEN   8

Definition at line 63 of file ssim.h.

---

Typedef Documentation

typedef int(* _map)(const struct _ssim_int *, void *)

Definition at line 83 of file ssim.h.

typedef float(* _reduce)(int, int, void *)

Definition at line 84 of file ssim.h.

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Function Documentation

float _iqa_ssim	(	float *	ref,
		float *	cmp,
		int	w,
		int	h,
		const struct _kernel *	k,
		const struct _map_reduce *	mr,
		const struct iqa_ssim_args *	args
	)

Private method that calculates the SSIM value on a pre-processed image.

The input images must have stride==width. This method does not scale.

Note:

Image buffers are modified.

Map-reduce is used for doing the final SSIM calculation. The map function is called for every pixel, and the reduce is called at the end. The context is caller-defined and *not* modified by this method.

Parameters:

ref	Original reference image
cmp	Distorted image
w	Width of the images
h	Height of the images
k	The kernel used as the window function
mr	Optional map-reduce functions to use to calculate SSIM. Required if 'args' is not null. Ignored if 'args' is null.
args	Optional SSIM arguments for fine control of the algorithm. 0 for defaults. Defaults are a=b=g=1.0, L=255, K1=0.01, K2=0.03

Returns:

The mean SSIM over the entire image (MSSIM), or NAN if error.

Definition at line 142 of file ssim.c.

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Variable Documentation

const float g_gaussian_window[GAUSSIAN_LEN][GAUSSIAN_LEN] [static]

Initial value:

 {
    {0.000001f, 0.000008f, 0.000037f, 0.000112f, 0.000219f, 0.000274f, 0.000219f, 0.000112f, 0.000037f, 0.000008f, 0.000001f},
    {0.000008f, 0.000058f, 0.000274f, 0.000831f, 0.001619f, 0.002021f, 0.001619f, 0.000831f, 0.000274f, 0.000058f, 0.000008f},
    {0.000037f, 0.000274f, 0.001296f, 0.003937f, 0.007668f, 0.009577f, 0.007668f, 0.003937f, 0.001296f, 0.000274f, 0.000037f},
    {0.000112f, 0.000831f, 0.003937f, 0.011960f, 0.023294f, 0.029091f, 0.023294f, 0.011960f, 0.003937f, 0.000831f, 0.000112f},
    {0.000219f, 0.001619f, 0.007668f, 0.023294f, 0.045371f, 0.056662f, 0.045371f, 0.023294f, 0.007668f, 0.001619f, 0.000219f},
    {0.000274f, 0.002021f, 0.009577f, 0.029091f, 0.056662f, 0.070762f, 0.056662f, 0.029091f, 0.009577f, 0.002021f, 0.000274f},
    {0.000219f, 0.001619f, 0.007668f, 0.023294f, 0.045371f, 0.056662f, 0.045371f, 0.023294f, 0.007668f, 0.001619f, 0.000219f},
    {0.000112f, 0.000831f, 0.003937f, 0.011960f, 0.023294f, 0.029091f, 0.023294f, 0.011960f, 0.003937f, 0.000831f, 0.000112f},
    {0.000037f, 0.000274f, 0.001296f, 0.003937f, 0.007668f, 0.009577f, 0.007668f, 0.003937f, 0.001296f, 0.000274f, 0.000037f},
    {0.000008f, 0.000058f, 0.000274f, 0.000831f, 0.001619f, 0.002021f, 0.001619f, 0.000831f, 0.000274f, 0.000058f, 0.000008f},
    {0.000001f, 0.000008f, 0.000037f, 0.000112f, 0.000219f, 0.000274f, 0.000219f, 0.000112f, 0.000037f, 0.000008f, 0.000001f},
}

Definition at line 45 of file ssim.h.

const float g_square_window[SQUARE_LEN][SQUARE_LEN] [static]

Initial value:

 {
    {0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f},
    {0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f},
    {0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f},
    {0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f},
    {0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f},
    {0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f},
    {0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f},
    {0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f, 0.015625f},
}

Definition at line 64 of file ssim.h.