You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
127 lines
3.4 KiB
127 lines
3.4 KiB
/******************************************************************************
|
|
*
|
|
* Copyright (C) 2015 The Android Open Source Project
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at:
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*
|
|
*****************************************************************************
|
|
* Originally developed and contributed by Ittiam Systems Pvt. Ltd, Bangalore
|
|
*/
|
|
/**
|
|
*******************************************************************************
|
|
* @file
|
|
* icv_variance.c
|
|
*
|
|
* @brief
|
|
* This file contains the functions to compute variance
|
|
*
|
|
* @author
|
|
* Ittiam
|
|
*
|
|
* @par List of Functions:
|
|
* icv_variance_8x4()
|
|
*
|
|
* @remarks
|
|
* None
|
|
*
|
|
*******************************************************************************
|
|
*/
|
|
/*****************************************************************************/
|
|
/* File Includes */
|
|
/*****************************************************************************/
|
|
/* System include files */
|
|
#include <stdio.h>
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
#include <stdlib.h>
|
|
#include <assert.h>
|
|
|
|
|
|
/* User include files */
|
|
#include "icv_datatypes.h"
|
|
#include "icv_macros.h"
|
|
#include "icv_platform_macros.h"
|
|
#include "icv.h"
|
|
|
|
/**
|
|
*******************************************************************************
|
|
*
|
|
* @brief
|
|
* Computes variance of a given 8x4 block
|
|
*
|
|
* @par Description
|
|
* Compute variance of a given 8x4 block
|
|
*
|
|
* @param[in] pu1_src
|
|
* Source
|
|
*
|
|
* @param[in] src_strd
|
|
* Source stride
|
|
*
|
|
* @param[in] wd
|
|
* Assumed to be 8
|
|
*
|
|
* @param[in] ht
|
|
* Assumed to be 4
|
|
*
|
|
* @returns
|
|
* Variance
|
|
*
|
|
* @remarks
|
|
*
|
|
*******************************************************************************
|
|
*/
|
|
WORD32 icv_variance_8x4(UWORD8 *pu1_src, WORD32 src_strd, WORD32 wd, WORD32 ht)
|
|
{
|
|
WORD32 sum;
|
|
WORD32 sum_sqr;
|
|
WORD32 blk_sz;
|
|
WORD32 vrnc;
|
|
WORD32 i;
|
|
WORD32 j;
|
|
UNUSED(wd);
|
|
UNUSED(ht);
|
|
|
|
ASSERT(wd == 8);
|
|
ASSERT(ht == 4);
|
|
|
|
sum = 0;
|
|
sum_sqr = 0;
|
|
|
|
blk_sz = 8 * 4;
|
|
|
|
/*************************************************************************/
|
|
/* variance */
|
|
/* var = (n * SUM(x_i^2) - (SUM(x_i))^2) / (n^2); */
|
|
/*************************************************************************/
|
|
|
|
/*************************************************************************/
|
|
/* The outer-loop runs for BLK_HT/2 times, because it */
|
|
/* calculates the variance only for field area not frame one. */
|
|
/*************************************************************************/
|
|
for(j = 0; j < 4; j ++)
|
|
{
|
|
for(i = 0; i < 8; i++)
|
|
{
|
|
sum_sqr += (*pu1_src) * (*pu1_src);
|
|
sum += *pu1_src++;
|
|
}
|
|
pu1_src += (src_strd - 8);
|
|
}
|
|
|
|
vrnc = ((sum_sqr * blk_sz) - (sum * sum)) / (blk_sz * blk_sz);
|
|
|
|
return vrnc;
|
|
}
|
|
|