rotatefastalt.c File Reference

Alternative (slightly slower) method for rotating color images, with antialiasing. This is here just for comparison with the better methods in the library. More...

#include <string.h>
#include <math.h>
#include "allheaders.h"

Go to the source code of this file.

Functions
static PIX *	pixRotateAMColorFast2 (PIX *pixs, l_float32 angle, l_uint8 grayval)
static PIX *	pixShiftRGB258 (PIX *pixs)
static void	rotateAMColorFastLow2 (l_uint32 *datad, l_int32 w, l_int32 h, l_int32 wpld, l_uint32 *datas, l_int32 wpls, l_float32 angle, l_uint8 grayval)
	main (int argc, char **argv)
Variables
static const l_float32	VERY_SMALL_ANGLE = 0.001

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Detailed Description

Alternative (slightly slower) method for rotating color images, with antialiasing. This is here just for comparison with the better methods in the library.

Definition in file rotatefastalt.c.

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Function Documentation

PIX * pixRotateAMColorFast2	(	PIX *	pixs,
		l_float32	angle,
		l_uint8	grayval
	)		[static]

pixRotateAMColorFast2()

Input: pixs angle (radians; clockwise is positive) grayval (0 to bring in BLACK, 255 for WHITE) Return: pixd, or null on error

Notes:

• This rotates a color image about the image center. A positive angle gives a clockwise rotation.
• It uses area mapping, dividing each pixel into 16 subpixels.
• It creates a temporary 32-bit color image.
• It is slightly slower than pixRotateAMColorFast(), which uses less memory because it does not create a temporary image.

*** Warning: implicit assumption about RGB component ordering ***

Definition at line 95 of file rotatefastalt.c.

References ERROR_PTR, L_ABS, NULL, pixClone(), pixCreateTemplate(), pixDestroy(), pixGetData(), pixGetDepth(), pixGetHeight(), pixGetWidth(), pixGetWpl(), pixShiftRGB258(), PROCNAME, rotateAMColorFastLow2(), and VERY_SMALL_ANGLE.

Referenced by main().

PIX * pixShiftRGB258

(

PIX *

pixs

)

[static]

pixShiftRGB258()

Makes a new 32 bpp image with the R, G and B components right-shifted by 2, 5 and 8 bits, respectively.

Definition at line 138 of file rotatefastalt.c.

References ERROR_PTR, NULL, pixCreate(), pixGetData(), pixGetDepth(), pixGetHeight(), pixGetWidth(), pixGetWpl(), and PROCNAME.

Referenced by pixRotateAMColorFast2().

void rotateAMColorFastLow2	(	l_uint32 *	datad,
		l_int32	w,
		l_int32	h,
		l_int32	wpld,
		l_uint32 *	datas,
		l_int32	wpls,
		l_float32	angle,
		l_uint8	grayval
	)		[static]

rotateAMColorFastLow2()

Alternative version for fast color rotation

*** Warning: explicit assumption about RGB component ordering ***

Definition at line 184 of file rotatefastalt.c.

Referenced by pixRotateAMColorFast2().

main	(	int	argc,
		char **	argv
	)

Definition at line 43 of file rotatefastalt.c.

References ERROR_INT, filein, IFF_JFIF_JPEG, NULL, pixDestroy(), pixRead(), pixRotateAMColorFast2(), pixWrite(), startTimer(), and stopTimer().

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Variable Documentation

const l_float32 VERY_SMALL_ANGLE = 0.001 [static]

Definition at line 34 of file rotatefastalt.c.

Referenced by pixRotateAMColorFast2().