Files
veejay/veejay-current/veejay-server/libvje/effects/bwotsu.c

148 lines
3.4 KiB
C

/*
* Linux VeeJay
*
* Copyright(C)2016 Niels Elburg <nwelburg@gmail.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License , or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307 , USA.
*/
#include <stdint.h>
#include <stdio.h>
#include <libvjmem/vjmem.h>
#include <math.h>
#include "bwotsu.h"
#include "common.h"
vj_effect *bwotsu_init(int w, int h)
{
vj_effect *ve = (vj_effect *) vj_calloc(sizeof(vj_effect));
ve->num_params = 3;
ve->defaults = (int *) vj_calloc(sizeof(int) * ve->num_params); /* default values */
ve->limits[0] = (int *) vj_calloc(sizeof(int) * ve->num_params); /* min */
ve->limits[1] = (int *) vj_calloc(sizeof(int) * ve->num_params); /* max */
ve->defaults[0] = 0;
ve->defaults[1] = 0xff;
ve->defaults[2] = 0;
ve->limits[0][0] = 0;
ve->limits[1][0] = 1;
ve->limits[0][1] = 0;
ve->limits[1][1] = 0xff;
ve->limits[0][2] = 0;
ve->limits[1][2] = 1;
ve->description = "Black and White Mask by Otsu's method";
ve->sub_format = -1;
ve->extra_frame = 0;
ve->has_user =0;
ve->parallel = 1;
ve->alpha = FLAG_ALPHA_OUT | FLAG_ALPHA_OPTIONAL;
ve->param_description = vje_build_param_list( ve->num_params, "To Alpha", "Skew", "Invert" );
return ve;
}
//@see https://en.wikipedia.org/wiki/Otsu's_method
static uint32_t bwotsu( uint32_t *H, const int N )
{
uint32_t threshold = 0;
double wF, wB=0.0, mB, mF, between, max = 0.0;
double sum = 0.0, sumB=0.0;
uint32_t i;
for( i = 0; i < 256; i++ )
{
wB += H[i];
if( wB == 0 )
continue;
wF = N - wB;
if( wF == 0 )
break;
sumB += ( i * H[i] );
mB = sumB / wB;
mF = (sum - sumB) / wF;
between = wB * wF * pow( mB - mF , 2 );
if( between > max ) {
max = between;
threshold = i;
}
}
return threshold;
}
void bwotsu_apply(VJFrame *frame, int mode, int skew, int invert)
{
uint32_t Histogram[256];
unsigned int i;
const int len = frame->len;
uint8_t *Y = frame->data[0];
uint8_t *A = frame->data[3];
veejay_memset( Histogram, 0, sizeof( Histogram ) );
if( skew != 0xff )
{
uint8_t Lookup[256];
__init_lookup_table( Lookup, 256, 0.0f, 255.0f, 0.0f, (float)skew );
for( i = 0; i < len; i ++ )
{
Histogram[ Lookup[ Y[i] ] ] += 1;
}
}
else
{
for( i = 0; i < len; i++ )
{
Histogram[ Y[i] ] += 1;
}
}
uint32_t threshold = bwotsu( Histogram, len );
uint8_t l = 0;
uint8_t h = 0xff;
if( invert ) {
l = 0xff;
h = 0;
}
switch( mode ) {
case 0:
for( i = 0; i < len; i ++ )
{
if( Y[i] < threshold )
Y[i] = l;
else
Y[i] = h;
}
veejay_memset( frame->data[1], 128, (frame->ssm ? frame->len : frame->uv_len) );
veejay_memset( frame->data[2], 128, (frame->ssm ? frame->len : frame->uv_len) );
break;
case 1:
for( i = 0; i < len; i ++ )
{
if( Y[i] < threshold )
A[i] = l;
else
A[i] = h;
}
break;
}
}