Voices of the Sun: Pseudo HDR effect using Pixilang

Here is my version of Pseudo HDR filter (tone mapping) for Pixilang. You can use it freely in any Pixilang applications.

/*
hdr_simulation.pixi

Copyright (c) 2012, Alexander Zolotov
http://www.warmplace.ru

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to
deal in the Software without restriction, including without limitation the
rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
IN THE SOFTWARE.
*/

scr = get_screen()
xsize = get_xsize( scr )
ysize = get_ysize( scr )
clear()

//$src - source image (container of PIXEL type)
//$filter_radius (in percent)
fn apply_hdr_effect( $src, $filter_radius, $intensity )
{
$src_xsize = get_xsize( $src )
$src_ysize = get_ysize( $src )

//Make grayscale copy:
$img2 = clone( $src )
$c = new( $src_xsize, $src_ysize, FLOAT32 )
split_rgb( 0, $src, -1, $c ) //Get red channel
split_rgb( 1, $img2, $c, $c, $c )

//Blur grayscale image:
$scr = get_screen()
set_screen( $img2 )
$size = ( $src_xsize * $filter_radius ) / 100
effector( EFF_HBLUR, $size )
effector( EFF_VBLUR, $size )
set_screen( $scr )

//Invert it:
op_cn( OP_XOR, $img2, WHITE )

//Do normalization:
split_rgb( 0, $img2, $c )
op_cc( OP_MUL, $c, $c ) //Add contrast
op_cc( OP_MUL, $c, $c ) //Add contrast
if $intensity != 1
{
op_cn( OP_MUL, $c, $intensity )
}
op_cn( OP_ADD, $c, 1 ) //Add base level
$r = clone( $c )
$g = clone( $c )
$b = clone( $c )
split_rgb( 0, $src, $r, $g, $b )
op_cc( OP_MUL, $r, $c )
op_cc( OP_MUL, $g, $c )
op_cc( OP_MUL, $b, $c )
split_rgb( 1, $src, $r, $g, $b )
remove( $r )
remove( $g )
remove( $b )

remove( $c )
remove( $img2 )
}

//Load image:
img = load( "images/dark.jpg" )
set_flags( img, CFLAG_INTERP )
img_xsize = get_xsize( img )
img_ysize = get_ysize( img )
s = 1
if img_xsize > xsize || img_ysize >= ysize
{
s1 = xsize / img_xsize
s2 = ysize / img_ysize
if s1 < s2 { s = s1 } else { s = s2 }
}
pixi( img, 0, 0, WHITE, s, s )
frame( 500 )

apply_hdr_effect( img, 3, 2 )
set_flags( img, CFLAG_INTERP )
save( img, "hdr.jpg", FORMAT_JPEG, 95 )

start_timer( 0 )
while 1
{
t = get_timer( 0 )
transp( t / 64 )
pixi( img, 0, 0, WHITE, s, s )
frame()
while get_event() { if EVT[ EVT_TYPE ] == EVT_QUIT { halt } }
}

The main function is apply_hdr_effect( $img, $radius, $intensity ) will apply Pseudo HDR effect to the selected image.
Parameters: $img - container with the image; $radius - blur-filter radius; $intensity - effect intensity.

Now let's see how it works.

Before: