#include "allheaders.h"

Data Structures
struct	ColorEl

Typedefs
typedef struct ColorEl	COLOREL

Functions
static COLOREL *	colorelCreate (l_int32 x, l_int32 y, l_uint32 color)

static void	pixColorFillFromSeed (PIX pixs, PIX pixv, PTA *ppta, l_int32 x, l_int32 y, L_QUEUE lq, l_int32 maxdiff, l_int32 minarea, l_int32 debug)

static void	pixGetVisitedNeighbors (PIX pixs, l_int32 x, l_int32 y, l_uint32 visited)

static l_int32	findNextUnvisited (PIX pixv, l_int32 px, l_int32 *py)

static l_int32	colorsAreSimilarForFill (l_uint32 val1, l_uint32 val2, l_int32 maxdiff)

static l_int32	pixelColorIsValid (l_uint32 val, l_int32 minmax)

static l_int32	pixelIsOnColorBoundary (PIX *pixs, l_int32 x, l_int32 y)

static l_int32	evalColorfillData (L_COLORFILL *cf, l_int32 debug)

L_COLORFILL *	l_colorfillCreate (PIX *pixs, l_int32 nx, l_int32 ny)

void	l_colorfillDestroy (L_COLORFILL **pcf)

l_ok	pixColorContentByLocation (L_COLORFILL *cf, l_int32 rref, l_int32 gref, l_int32 bref, l_int32 minmax, l_int32 maxdiff, l_int32 minarea, l_int32 smooth, l_int32 debug)

PIX *	pixColorFill (PIX *pixs, l_int32 minmax, l_int32 maxdiff, l_int32 smooth, l_int32 minarea, l_int32 debug)

PIXA *	makeColorfillTestData (l_int32 w, l_int32 h, l_int32 nseeds, l_int32 range)

Variables
static l_int32	DefaultMinMax = 70

Detailed Description


     Determine color content using proximity.  What can we say about the
     color in an image from growing regions with nearly the same color?

        L_COLORFILL  *l_colorfillCreate()
        void          l_colorfillDestroy()

        L_COLORFILL  *pixColorContentByLocation()
        PIX          *pixColorFill()

     Generate data for testing
        PIXA         *makeColorfillTestData()

     Static helpers
        static COLOREL      *colorelCreate()
        static void          pixColorFillFromSeed()
        static void          pixGetVisitedNeighbors()
        static l_int32       findNextUnvisited()
        static l_int32       colorsAreSimilarForFill()
        static void          pixelColorIsValid()
        static l_int32       pixelIsOnColorBoundary()
        static l_int32       evalColorfillData()

 See colorcontent.c for location-independent measures of the amount
 of color in an image.

Definition in file colorfill.c.

Typedef Documentation

◆ COLOREL

typedef struct ColorEl COLOREL

Definition at line 69 of file colorfill.c.

Function Documentation

◆ colorelCreate()

static COLOREL * colorelCreate	(	l_int32	x,
		l_int32	y,
		l_uint32	color )

static

Definition at line 491 of file colorfill.c.

◆ colorsAreSimilarForFill()

static l_int32 colorsAreSimilarForFill	(	l_uint32	val1,
		l_uint32	val2,
		l_int32	maxdiff )

static

colorsAreSimilarForFill()

Parameters

[in]	val1	color of pixel 1, as 0xrrggbb00
[in]	val2	color of pixel 2, as 0xrrggbb00
[in]	maxdiff	max of difference function to be similar

Returns: 1 if val1 and val2 are similar; 0 otherwise

Notes:
     (1) An example will explain the approach.  Suppose we have:
           val1 = {100, 130, 70}
           val2 = {90, 135, 62}
         First find that red is the color with largest abs(difference):
           rdiff = val1 - val2 = 10
         Find the green and blue differences
           gdiff = 130 - 135 = -5
           bdiff = 70 - 62 = 8
         and subtract each from rdiff:
           rdiff - gdiff = 15
           rdiff - bdiff = 7
         The max of these is 15, which is then compared with maxdiff

Definition at line 750 of file colorfill.c.

Referenced by pixColorFillFromSeed().

◆ evalColorfillData()

static l_int32 evalColorfillData	(	L_COLORFILL *	cf,
		l_int32	debug )

static

evalColorfillData()

Parameters

[in]	cf	colorfill with masks generated for all tiles
[in]	debug	show segmented regions with their median color

Returns: 0 if OK, 1 on error

Definition at line 842 of file colorfill.c.

References L_Colorfill::dnaa, L_CLONE, L_COPY, L_INSERT, L_Colorfill::naa, L_Colorfill::nx, L_Colorfill::ny, L_Colorfill::pixadb, L_Colorfill::pixam, and L_Colorfill::pixas.

Referenced by pixColorContentByLocation().

◆ findNextUnvisited()

static l_int32 findNextUnvisited	(	PIX *	pixv,
		l_int32 *	px,
		l_int32 *	py )

static

findNextUnvisited()

Parameters

[in]	pixv	visited pixels
[in,out]	py	input start scanline; output y-coord of next seed
[out]	px	x-coord of next seed

Returns: 1 if new seed point is found; 0 if there are none

Notes:
     (1) Start the search at the beginning of the raster line
         for the pixel that ended the previous search.

Definition at line 710 of file colorfill.c.

Referenced by pixColorFill().

◆ l_colorfillCreate()

L_COLORFILL * l_colorfillCreate	(	PIX *	pixs,
		l_int32	nx,
		l_int32	ny )

l_colorfillCreate()

Parameters

[in]	pixs	input RGB image
[in]	nx	requested number of tiles in each row
[in]	ny	requested number of tiles in each column

Returns: boxa, or NULL on error

Notes:
     (1) Tiles must at least 10 pixels in each dimension.

Definition at line 107 of file colorfill.c.

References L_Colorfill::boxas, L_Colorfill::dnaa, L_INSERT, L_Colorfill::naa, L_Colorfill::nx, L_Colorfill::ny, L_Colorfill::pixadb, L_Colorfill::pixs, L_Colorfill::th, and L_Colorfill::tw.

◆ l_colorfillDestroy()

void l_colorfillDestroy ( L_COLORFILL ** pcf )

l_colorfillDestroy()

Parameters

[in,out] pcf will be set to null before returning

Returns: void

Definition at line 156 of file colorfill.c.

References L_Colorfill::boxas, L_Colorfill::dnaa, L_Colorfill::naa, L_Colorfill::pixadb, L_Colorfill::pixam, L_Colorfill::pixas, L_Colorfill::pixs, and L_Colorfill::pixst.

◆ makeColorfillTestData()

PIXA * makeColorfillTestData	(	l_int32	w,
		l_int32	h,
		l_int32	nseeds,
		l_int32	range )

makeColorfillTestData()

Parameters

[in]	w	width of generated pix
[in]	h	height of generated pix
[in]	nseeds	number of regions
[in]	range	of color component values

Returns: pixa various pix with filled regions of random color, or NULL on error

Notes:
     (1) The seeds are random points.  The colors are assigned
         randomly from a restricted range of component values,
         in [128 - range/2 ... 128 + range/2]
     (2) Output is pixa:
         * pixa[0] cmapped, with color regions shown
         - pixa[1] cmapped, additionally with boundary pixels set to black
         - pixa[2] cmapped, as in pixa[1] with all non-black pixels
                   in the same color

Definition at line 404 of file colorfill.c.

References L_COPY, L_INSERT, and pixelIsOnColorBoundary().

◆ pixColorContentByLocation()

l_ok pixColorContentByLocation	(	L_COLORFILL *	cf,
		l_int32	rref,
		l_int32	gref,
		l_int32	bref,
		l_int32	minmax,
		l_int32	maxdiff,
		l_int32	minarea,
		l_int32	smooth,
		l_int32	debug )

pixColorContentByLocation()

Parameters

[in]	cf	colorfill
[in]	rref	reference value for red component
[in]	gref	reference value for green component
[in]	bref	reference value for blue component
[in]	minmax	min of max component for possible color region
[in]	maxdiff	max component diff to be in same color region
[in]	minarea	min number of pixels for a color region
[in]	smooth	low-pass kernel size (1,3,5); use 1 to skip
[in]	debug	generates debug images and fill info

Returns: 0 if OK, 1 on error

Notes:
     (1) This computes color fill information in each tile, identifying
         regions of approximately constant color.  It does this
         independently for each tile, using flood fills.  Regions
         of low intensity are considered 'not colorful'.
     (2) The three numbers (rref, gref and bref) can be thought
         of in two ways:
           (a) as rgb values in the image corresponding to white,
               to compensate for an unbalanced color white point.
           (b) as the median or mean values of the background color
               of a scan.
         The gamma TRC transformation, which does not change hue, is used
         to modify all colors so that these reference values become white.
         These three numbers must either be all 0 or all non-zero.
         To skip the TRC transform, set them all to 0.
     (3) If the maximum component after white point correction,
         max(r,g,b), is less than minmax, the pixel color is invalid, and it
         is assigned its neighbor's value in the filling operation.
         Use minmax = 0 for a default value.

Definition at line 222 of file colorfill.c.

References L_Colorfill::boxas, evalColorfillData(), L_COPY, L_INSERT, L_Colorfill::pixam, L_Colorfill::pixas, pixColorFill(), L_Colorfill::pixs, and L_Colorfill::pixst.

◆ pixColorFill()

PIX * pixColorFill	(	PIX *	pixs,
		l_int32	minmax,
		l_int32	maxdiff,
		l_int32	smooth,
		l_int32	minarea,
		l_int32	debug )

pixColorFill()

Parameters

[in]	pixs	32 bpp RGB
[in]	minmax	min of max component for possible color region
[in]	maxdiff	max component diff to be in same color region
[in]	smooth	low-pass kernel size (1,3,5); use 1 to skip
[in]	minarea	min number of pixels for a color region
[in]	debug	generates debug images and fill info

Returns: pixm mask showing connected regions of similar color, or null on error

Notes:
     (1) This is the basic color filling operation.  It sets the
         non-color pixel to black, optionally does a low-pass filter,
         and grows the 8-connected color components.  Finally, it
         removes components that have a small area.

Definition at line 293 of file colorfill.c.

References findNextUnvisited(), L_SELECT_IF_GTE, pixColorFillFromSeed(), and pixelColorIsValid().

Referenced by pixColorContentByLocation().

◆ pixColorFillFromSeed()

static void pixColorFillFromSeed	(	PIX *	pixs,
		PIX *	pixv,
		PTA **	ppta,
		l_int32	x,
		l_int32	y,
		L_QUEUE *	lq,
		l_int32	maxdiff,
		l_int32	minarea,
		l_int32	debug )

static

pixColorFillFromSeed()

Parameters

[in]	pixs	32 bpp rgb
[in]	pixv	1 bpp labeling visited pixels
[out]	ppta	points visited with similar colors during fill
[in]	x	starting x coord for fill (seed)
[in]	y	starting y coord for fill (seed)
[in]	lq	head of queue holding pixels
[in]	maxdiff	max component diff allowed for similar pixels
[in]	minarea	min size of component to keep
[in]	debug	output some text data

Returns: void

Notes:
     (1) Use 8-connected filling.  It is faster because it reduces the
         number of single-pixel noise components near color boundaries.
     (2) The seed pixel at (x,y) is unvisited, and can never be on the
         exterior boundary of the tile pixs.
     (3) If the size of the connected component >= minarea, we return
         the array of pixel locations; otherwise, return NULL for the pta.

Definition at line 529 of file colorfill.c.

References colorsAreSimilarForFill(), and pixGetVisitedNeighbors().

Referenced by pixColorFill().

◆ pixelColorIsValid()

static l_int32 pixelColorIsValid	(	l_uint32	val,
		l_int32	minmax )

static

pixelColorIsValid()

Parameters

[in]	val	color, as 0xrrggbb00
[in]	minmax	max component must be < minmax to be valid

Returns: 0 if max component < minmax; 1 otherwise

Definition at line 783 of file colorfill.c.

Referenced by pixColorFill().

◆ pixelIsOnColorBoundary()

static l_int32 pixelIsOnColorBoundary	(	PIX *	pixs,
		l_int32	x,
		l_int32	y )

static

pixelIsOnColorBoundary()

Parameters

[in]	pixs	32 bpp rgb or 8 bpp with colormap
[in]	x,y	location of pixel of interest

Returns: 1 if at least one neighboring pixel had a different color; 0 otherwise.

Definition at line 805 of file colorfill.c.

Referenced by makeColorfillTestData().

◆ pixGetVisitedNeighbors()

static void pixGetVisitedNeighbors	(	PIX *	pixs,
		l_int32	x,
		l_int32	y,
		l_uint32 *	visited )

static

pixGetVisitedNeighbors()

Parameters

[in]	pixs	1 bpp, representing visited locations
[in]	x	x coord of pixel
[in]	y	y coord of pixel
[in,out]	visited	array of 8 int

Returns: void

Notes:
     (1) The values of the neighbors of (x,y) in pixs, given in
         order {W,N,E,S,NW,NE,SW,SE}, are returned in visited.
         A "1" value means that pixel has been visited.  Initialize
         each neighbor to 1 (visited).
     (2) The input point (x,y) is never on the outer boundary of pixs,
         (e.g., x >= 1, y >= 1), so no checking is required.

Definition at line 679 of file colorfill.c.

Referenced by pixColorFillFromSeed().

Variable Documentation

◆ DefaultMinMax

l_int32 DefaultMinMax = 70

static

Definition at line 72 of file colorfill.c.

Data Structures

Typedefs

Functions

Variables

Detailed Description

Typedef Documentation

◆ COLOREL

Function Documentation

◆ colorelCreate()

◆ colorsAreSimilarForFill()

◆ evalColorfillData()

◆ findNextUnvisited()

◆ l_colorfillCreate()

◆ l_colorfillDestroy()

◆ makeColorfillTestData()

◆ pixColorContentByLocation()

◆ pixColorFill()

◆ pixColorFillFromSeed()

◆ pixelColorIsValid()

◆ pixelIsOnColorBoundary()

◆ pixGetVisitedNeighbors()

Variable Documentation

◆ DefaultMinMax