op_c.h File Reference

Color reduction and color conversion (24b->8b, RGB<->HSL). More...

#include "struct.h"
#include "colorred.h"

Include dependency graph for op_c.h:

This graph shows which files directly or indirectly include this file:

Data Structures
struct	T_Occurrence_table
	Occurence table. More...
struct	S_Cluster_CutData
	informations used while median-cutting. More...
struct	S_Cluster_PalData
	information used while color reducing More...
union	U_Cluster_Data
struct	T_Cluster
	Color cluster. More...
struct	T_Cluster_set
	Cluster set. More...
struct	T_Gradient
	Gradient. More...
struct	T_Gradient_set

Typedefs
typedef T_Components *	T_Bitmap24B
typedef byte *	T_Bitmap256

Functions
void	RGB_to_HSL (int r, int g, int b, byte *h, byte *s, byte *l)
	Convert RGB to HSL. More...
void	HSL_to_RGB (byte h, byte s, byte l, byte *r, byte *g, byte *b)
	Convert HSL back to RGB Input and output are all in range 0..255. More...
long	Perceptual_lightness (T_Components *color)
	Returns a value that is high when color is near white, and low when it's darker. More...
void	OT_init (T_Occurrence_table *t)
	Initialize an occurrence table. More...
T_Occurrence_table *	OT_new (int nbb_r, int nbb_g, int nbb_b)
	Allocate an occurrence table for given number of bits. More...
void	OT_delete (T_Occurrence_table *t)
	Delete a table and free the memory. More...
int	OT_get (T_Occurrence_table *t, byte r, byte g, byte b)
	Get number of occurrences for a given color. More...
void	OT_inc (T_Occurrence_table *t, byte r, byte g, byte b)
	Add 1 to the count for a color. More...
void	OT_count_occurrences (T_Occurrence_table *t, T_Bitmap24B image, int size)
	Count the use of each color in a 24bit picture and fill in the table. More...
void	Cluster_pack (T_Cluster *c, const T_Occurrence_table *const to)
	Pack a cluster, ie compute its {r,v,b}{min,max} values. More...
void	Cluster_split (T_Cluster *c, T_Cluster *c1, T_Cluster *c2, int hue, const T_Occurrence_table *const to)
	Split a cluster on its longest axis. More...
void	Cluster_compute_hue (T_Cluster *c, T_Occurrence_table *to)
	Compute the mean R, G, B (for palette generation) and H, L (for palette sorting) More...
void	CS_Init (T_Cluster_set *cs, T_Occurrence_table *to)
	Setup the first cluster before we start the operations This one covers the full palette range. More...
T_Cluster_set *	CS_New (int nbmax, T_Occurrence_table *to)
	Allocate a new cluster set. More...
void	CS_Delete (T_Cluster_set *cs)
	Free a cluster set. More...
void	CS_Get (T_Cluster_set *cs, T_Cluster **c)
	Pop a cluster from the cluster list. More...
int	CS_Set (T_Cluster_set *cs, T_Cluster *c)
	Push a copy of a cluster in the list return -1 in case of error. More...
int	CS_Generate (T_Cluster_set *cs, const T_Occurrence_table *const to, CT_Tree *colorTree)
	This is the main median cut algorithm and the function actually called to reduce the palette. More...
void	CS_Compute_colors (T_Cluster_set *cs, T_Occurrence_table *to)
	Compute the color associated to each box in the list. More...
void	CS_Generate_color_table_and_palette (T_Cluster_set *cs, CT_Tree *tc, T_Components *palette, T_Occurrence_table *to)
	Generates the palette from the clusters, then the conversion table to map (RGB) to a palette index. More...
void	GS_Init (T_Gradient_set *ds, T_Cluster_set *cs)
T_Gradient_set *	GS_New (T_Cluster_set *cs)
void	GS_Delete (T_Gradient_set *ds)
void	GS_Generate (T_Gradient_set *ds, T_Cluster_set *cs)
int	Convert_24b_bitmap_to_256 (T_Bitmap256 dest, T_Bitmap24B source, int width, int height, T_Components *palette)
	Converts a 24 bit picture to 256 color (color reduction) More...

Detailed Description

Color reduction and color conversion (24b->8b, RGB<->HSL).

This is called op_c because half of the process was originally coded in op_asm, in assembler.

Typedef Documentation

T_Bitmap24B

typedef T_Components* T_Bitmap24B

T_Bitmap256

typedef byte* T_Bitmap256

Function Documentation

RGB_to_HSL()

void RGB_to_HSL	(	int	r,
		int	g,
		int	b,
		byte *	hr,
		byte *	sr,
		byte *	lr
	)

Convert RGB to HSL.

Both input and output are in the 0..255 range to use in the palette screen

Referenced by Button_Palette(), Cluster_compute_hue(), Compute_optimal_menu_colors(), Display_sliders(), Draw_all_palette_sliders(), and Set_HSL().

HSL_to_RGB()

void HSL_to_RGB	(	byte	h,
		byte	s,
		byte	l,
		byte *	r,
		byte *	g,
		byte *	b
	)

Convert HSL back to RGB Input and output are all in range 0..255.

Referenced by Button_Palette(), and Set_HSL().

Perceptual_lightness()

long Perceptual_lightness

(

T_Components *

color

)

Returns a value that is high when color is near white, and low when it's darker.

Used for sorting.

References T_Components::B, T_Components::G, and T_Components::R.

Referenced by Button_Palette().

OT_init()

void OT_init

(

T_Occurrence_table *

t

)

Initialize an occurrence table.

References T_Occurrence_table::rng_b, T_Occurrence_table::rng_g, T_Occurrence_table::rng_r, and T_Occurrence_table::table.

OT_new()

T_Occurrence_table * OT_new	(	int	nbb_r,
		int	nbb_g,
		int	nbb_b
	)

Allocate an occurrence table for given number of bits.

References T_Occurrence_table::dec_b, T_Occurrence_table::dec_g, T_Occurrence_table::dec_r, T_Occurrence_table::nbb_b, T_Occurrence_table::nbb_g, T_Occurrence_table::nbb_r, NULL, T_Occurrence_table::red_b, T_Occurrence_table::red_g, T_Occurrence_table::red_r, T_Occurrence_table::rng_b, T_Occurrence_table::rng_g, T_Occurrence_table::rng_r, and T_Occurrence_table::table.

Referenced by Optimize_palette().

OT_delete()

void OT_delete

(

T_Occurrence_table *

t

)

Delete a table and free the memory.

References NULL, and T_Occurrence_table::table.

Referenced by Optimize_palette().

OT_get()

int OT_get	(	T_Occurrence_table *	t,
		byte	r,
		byte	g,
		byte	b
	)

Get number of occurrences for a given color.

References T_Occurrence_table::dec_b, T_Occurrence_table::dec_g, T_Occurrence_table::dec_r, and T_Occurrence_table::table.

Referenced by Cluster_compute_hue().

OT_inc()

void OT_inc	(	T_Occurrence_table *	t,
		byte	r,
		byte	g,
		byte	b
	)

Add 1 to the count for a color.

References T_Occurrence_table::dec_b, T_Occurrence_table::dec_g, T_Occurrence_table::dec_r, T_Occurrence_table::red_b, T_Occurrence_table::red_g, T_Occurrence_table::red_r, and T_Occurrence_table::table.

Referenced by OT_count_occurrences().

OT_count_occurrences()

void OT_count_occurrences	(	T_Occurrence_table *	t,
		T_Bitmap24B	image,
		int	size
	)

Count the use of each color in a 24bit picture and fill in the table.

References T_Components::B, T_Components::G, OT_inc(), and T_Components::R.

Referenced by Optimize_palette().

Cluster_pack()

void Cluster_pack	(	T_Cluster *	c,
		const T_Occurrence_table *const	to
	)

Pack a cluster, ie compute its {r,v,b}{min,max} values.

References T_Cluster::bmax, T_Cluster::bmin, U_Cluster_Data::cut, T_Cluster::data, T_Occurrence_table::dec_b, T_Occurrence_table::dec_g, T_Occurrence_table::dec_r, T_Cluster::occurences, S_Cluster_CutData::plus_large, T_Cluster::rmax, T_Cluster::rmin, S_Cluster_CutData::sqdiag, T_Occurrence_table::table, T_Cluster::vmax, T_Cluster::vmin, and S_Cluster_CutData::volume.

Referenced by CS_Generate(), and CS_Init().

Cluster_split()

void Cluster_split	(	T_Cluster *	c,
		T_Cluster *	c1,
		T_Cluster *	c2,
		int	hue,
		const T_Occurrence_table *const	to
	)

Split a cluster on its longest axis.

c = source cluster, c1, c2 = output after split the two output clusters have half population (and not half volume)

References T_Cluster::bmax, T_Cluster::Bmax, T_Cluster::bmin, T_Cluster::Bmin, T_Cluster::Gmin, T_Cluster::occurences, T_Cluster::rmax, T_Cluster::Rmax, T_Cluster::rmin, T_Cluster::Rmin, T_Cluster::vmax, T_Cluster::Vmax, and T_Cluster::vmin.

Referenced by CS_Generate().

Cluster_compute_hue()

void Cluster_compute_hue	(	T_Cluster *	c,
		T_Occurrence_table *	to
	)

Compute the mean R, G, B (for palette generation) and H, L (for palette sorting)

References S_Cluster_PalData::b, T_Cluster::bmin, T_Cluster::data, S_Cluster_PalData::g, S_Cluster_PalData::h, S_Cluster_PalData::l, T_Cluster::occurences, OT_get(), U_Cluster_Data::pal, S_Cluster_PalData::r, T_Occurrence_table::red_b, T_Occurrence_table::red_g, T_Occurrence_table::red_r, RGB_to_HSL(), T_Cluster::rmin, and T_Cluster::vmin.

Referenced by CS_Compute_colors().

CS_Init()

void CS_Init	(	T_Cluster_set *	cs,
		T_Occurrence_table *	to
	)

Setup the first cluster before we start the operations This one covers the full palette range.

References T_Cluster::bmax, T_Cluster::Bmax, T_Cluster::bmin, T_Cluster::Bmin, Cluster_pack(), T_Cluster_set::clusters, T_Cluster::Gmin, T_Cluster_set::nb, T_Cluster::next, NULL, T_Cluster::rmax, T_Cluster::Rmax, T_Cluster::rmin, T_Cluster::Rmin, T_Occurrence_table::rng_b, T_Occurrence_table::rng_g, T_Occurrence_table::rng_r, T_Cluster::vmax, T_Cluster::Vmax, and T_Cluster::vmin.

Referenced by CS_New().

CS_New()

T_Cluster_set * CS_New	(	int	nbmax,
		T_Occurrence_table *	to
	)

Allocate a new cluster set.

References T_Cluster_set::clusters, CS_Init(), T_Cluster_set::nb_max, NULL, and OT_count_colors().

Referenced by Optimize_palette().

CS_Delete()

void CS_Delete

(

T_Cluster_set *

cs

)

Free a cluster set.

References T_Cluster_set::clusters, T_Cluster::next, and NULL.

Referenced by Optimize_palette().

CS_Get()

void CS_Get	(	T_Cluster_set *	cs,
		T_Cluster **	c
	)

Pop a cluster from the cluster list.

References T_Cluster_set::clusters, T_Cluster_set::nb, and T_Cluster::next.

Referenced by CS_Generate().

CS_Set()

int CS_Set	(	T_Cluster_set *	cs,
		T_Cluster *	c
	)

Push a copy of a cluster in the list return -1 in case of error.

References T_Cluster_set::clusters, U_Cluster_Data::cut, T_Cluster::data, T_Cluster_set::nb, T_Cluster::next, NULL, S_Cluster_CutData::sqdiag, and S_Cluster_CutData::volume.

Referenced by CS_Generate().

CS_Generate()

int CS_Generate	(	T_Cluster_set *	cs,
		const T_Occurrence_table *const	to,
		CT_Tree *	colorTree
	)

This is the main median cut algorithm and the function actually called to reduce the palette.

We get the number of pixels for each collor in the occurrence table and generate the cluster set from it.

References T_Cluster::Bmax, T_Cluster::Bmin, Cluster_pack(), Cluster_split(), CS_Get(), CS_Set(), CT_set_trad(), U_Cluster_Data::cut, T_Cluster::data, T_Cluster::Gmin, T_Cluster_set::nb, T_Cluster_set::nb_max, T_Cluster::occurences, S_Cluster_CutData::plus_large, T_Cluster::Rmax, T_Cluster::Rmin, T_Cluster::Vmax, and S_Cluster_CutData::volume.

Referenced by Optimize_palette().

CS_Compute_colors()

void CS_Compute_colors	(	T_Cluster_set *	cs,
		T_Occurrence_table *	to
	)

Compute the color associated to each box in the list.

References Cluster_compute_hue(), T_Cluster_set::clusters, T_Cluster::next, and NULL.

Referenced by Optimize_palette().

CS_Generate_color_table_and_palette()

void CS_Generate_color_table_and_palette	(	T_Cluster_set *	cs,
		CT_Tree *	tc,
		T_Components *	palette,
		T_Occurrence_table *	to
	)

Generates the palette from the clusters, then the conversion table to map (RGB) to a palette index.

References S_Cluster_PalData::b, T_Components::B, T_Cluster::Bmax, T_Cluster::Bmin, T_Cluster_set::clusters, CT_set_trad(), T_Cluster::data, S_Cluster_PalData::g, T_Components::G, T_Cluster::Gmin, T_Cluster_set::nb, T_Cluster::next, U_Cluster_Data::pal, S_Cluster_PalData::r, T_Components::R, T_Cluster::Rmax, T_Cluster::Rmin, and T_Cluster::Vmax.

Referenced by Optimize_palette().

GS_Init()

void GS_Init	(	T_Gradient_set *	ds,
		T_Cluster_set *	cs
	)

References T_Cluster_set::clusters, T_Cluster::data, T_Gradient_set::gradients, S_Cluster_PalData::h, T_Gradient::hue, T_Gradient::max, T_Gradient::min, T_Gradient_set::nb, T_Gradient::nb_colors, and U_Cluster_Data::pal.

Referenced by GS_New().

GS_New()

T_Gradient_set * GS_New

(

T_Cluster_set *

cs

)

References T_Gradient_set::gradients, GS_Init(), T_Cluster_set::nb_max, T_Gradient_set::nb_max, and NULL.

Referenced by Optimize_palette().

GS_Delete()

void GS_Delete

(

T_Gradient_set *

ds

)

References T_Gradient_set::gradients.

Referenced by Optimize_palette().

GS_Generate()

void GS_Generate	(	T_Gradient_set *	ds,
		T_Cluster_set *	cs
	)

References T_Cluster_set::clusters, T_Cluster::data, T_Gradient_set::gradients, S_Cluster_PalData::h, T_Gradient::hue, id, T_Gradient::max, T_Gradient::min, T_Gradient_set::nb, T_Gradient::nb_colors, T_Cluster::next, and U_Cluster_Data::pal.

Referenced by Optimize_palette().

Convert_24b_bitmap_to_256()

int Convert_24b_bitmap_to_256	(	T_Bitmap256	dest,
		T_Bitmap24B	source,
		int	width,
		int	height,
		T_Components *	palette
	)

Converts a 24 bit picture to 256 color (color reduction)

Parameters

[out]	dest	The converted 8bpp picture
[in]	source	the 24bpp picture
[in]	width	the width of the picture
[in]	height	the height of the picture
[out]	palette	the palette of the converted 8bpp picture

Returns

0 for OK, 1 for error

References Convert_24b_bitmap_to_256_nearest_neighbor(), CT_delete(), NULL, Optimize_palette(), precision_24b, and Try_Convert_to_256_Without_Loss().

Referenced by Load_image(), and Test_Convert_24b_bitmap_to_256().