sanei_magic.h File Reference

This file provides an interface to simple image post-processing functions. More...

Go to the source code of this file.

Functions
void	sanei_magic_init (void)
	Initialize sanei_magic. More...
SANE_Status	sanei_magic_despeck (SANE_Parameters *params, SANE_Byte *buffer, SANE_Int diam)
	Update the image buffer, replacing dots with surrounding background color. More...
SANE_Status	sanei_magic_findSkew (SANE_Parameters *params, SANE_Byte *buffer, int dpiX, int dpiY, int *centerX, int *centerY, double *finSlope)
	Find the skew of the media inside the image, via edge detection. More...
SANE_Status	sanei_magic_rotate (SANE_Parameters *params, SANE_Byte *buffer, int centerX, int centerY, double slope, int bg_color)
	Correct the skew of the media inside the image, via simple rotation. More...
SANE_Status	sanei_magic_findEdges (SANE_Parameters *params, SANE_Byte *buffer, int dpiX, int dpiY, int *top, int *bot, int *left, int *right)
	Find the edges of the media inside the image, parallel to image edges. More...
SANE_Status	sanei_magic_crop (SANE_Parameters *params, SANE_Byte *buffer, int top, int bot, int left, int right)
	Crop the image, parallel to image edges. More...
SANE_Status	sanei_magic_isBlank (SANE_Parameters *params, SANE_Byte *buffer, double thresh)
	Determine if image is blank. More...
SANE_Status	sanei_magic_isBlank2 (SANE_Parameters *params, SANE_Byte *buffer, int dpiX, int dpiY, double thresh)
	Determine if image is blank, enhanced version. More...
SANE_Status	sanei_magic_findTurn (SANE_Parameters *params, SANE_Byte *buffer, int dpiX, int dpiY, int *angle)
	Determine coarse image rotation (90 degree increments) More...
SANE_Status	sanei_magic_turn (SANE_Parameters *params, SANE_Byte *buffer, int angle)
	Coarse image rotation (90 degree increments) More...

Detailed Description

This file provides an interface to simple image post-processing functions.

Currently, three operations are provided:

• Deskew (correct rotated scans, by detecting media edges)
• Autocrop (reduce image size to minimum rectangle containing media)
• Despeckle (replace dots of significantly different color with background)
• Blank detection (check if density is over a threshold)
• Rotate (detect and correct 90 degree increment rotations)

Note that these functions are simplistic, and are expected to change. Patches and suggestions are welcome.

Function Documentation

sanei_magic_init()

void sanei_magic_init

(

void

)

Initialize sanei_magic.

Call this before any other sanei_magic function.

sanei_magic_despeck()

SANE_Status sanei_magic_despeck	(	SANE_Parameters *	params,
		SANE_Byte *	buffer,
		SANE_Int	diam
	)

Update the image buffer, replacing dots with surrounding background color.

Parameters

params	describes image
buffer	contains image data
diam	maximum dot diameter to remove

Returns

• SANE_STATUS_GOOD - success
• SANE_STATUS_INVAL - invalid image parameters

sanei_magic_findSkew()

SANE_Status sanei_magic_findSkew	(	SANE_Parameters *	params,
		SANE_Byte *	buffer,
		int	dpiX,
		int	dpiY,
		int *	centerX,
		int *	centerY,
		double *	finSlope
	)

Find the skew of the media inside the image, via edge detection.

Parameters

	params	describes image
	buffer	contains image data
	dpiX	horizontal resolution
	dpiY	vertical resolution
[out]	centerX	horizontal coordinate of center of rotation
[out]	centerY	vertical coordinate of center of rotation
[out]	finSlope	slope of rotation

Returns

• SANE_STATUS_GOOD - success
• SANE_STATUS_NO_MEM - not enough memory
• SANE_STATUS_INVAL - invalid image parameters
• SANE_STATUS_UNSUPPORTED - slope angle too shallow to detect

sanei_magic_rotate()

SANE_Status sanei_magic_rotate	(	SANE_Parameters *	params,
		SANE_Byte *	buffer,
		int	centerX,
		int	centerY,
		double	slope,
		int	bg_color
	)

Correct the skew of the media inside the image, via simple rotation.

Parameters

params	describes image
buffer	contains image data
centerX	horizontal coordinate of center of rotation
centerY	vertical coordinate of center of rotation
slope	slope of rotation
bg_color	the replacement color for edges exposed by rotation

Returns

• SANE_STATUS_GOOD - success
• SANE_STATUS_NO_MEM - not enough memory
• SANE_STATUS_INVAL - invalid image parameters

sanei_magic_findEdges()

SANE_Status sanei_magic_findEdges	(	SANE_Parameters *	params,
		SANE_Byte *	buffer,
		int	dpiX,
		int	dpiY,
		int *	top,
		int *	bot,
		int *	left,
		int *	right
	)

Find the edges of the media inside the image, parallel to image edges.

Parameters

	params	describes image
	buffer	contains image data
	dpiX	horizontal resolution
	dpiY	vertical resolution
[out]	top	vertical offset to upper edge of media
[out]	bot	vertical offset to lower edge of media
[out]	left	horizontal offset to left edge of media
[out]	right	horizontal offset to right edge of media

Returns

• SANE_STATUS_GOOD - success
• SANE_STATUS_NO_MEM - not enough memory
• SANE_STATUS_UNSUPPORTED - edges could not be detected

sanei_magic_crop()

SANE_Status sanei_magic_crop	(	SANE_Parameters *	params,
		SANE_Byte *	buffer,
		int	top,
		int	bot,
		int	left,
		int	right
	)

Crop the image, parallel to image edges.

Parameters

params	describes image
buffer	contains image data
top	vertical offset to upper edge of crop
bot	vertical offset to lower edge of crop
left	horizontal offset to left edge of crop
right	horizontal offset to right edge of crop

Returns

• SANE_STATUS_GOOD - success
• SANE_STATUS_NO_MEM - not enough memory
• SANE_STATUS_INVAL - invalid image parameters

sanei_magic_isBlank()

SANE_Status sanei_magic_isBlank	(	SANE_Parameters *	params,
		SANE_Byte *	buffer,
		double	thresh
	)

Determine if image is blank.

Parameters

params	describes image
buffer	contains image data
thresh	maximum % density for blankness (0-100)

Returns

• SANE_STATUS_GOOD - page is not blank
• SANE_STATUS_NO_DOCS - page is blank
• SANE_STATUS_NO_MEM - not enough memory
• SANE_STATUS_INVAL - invalid image parameters

sanei_magic_isBlank2()

SANE_Status sanei_magic_isBlank2	(	SANE_Parameters *	params,
		SANE_Byte *	buffer,
		int	dpiX,
		int	dpiY,
		double	thresh
	)

Determine if image is blank, enhanced version.

Parameters

params	describes image
buffer	contains image data
dpiX	horizontal resolution
dpiY	vertical resolution
thresh	maximum % density for blankness (0-100)

Returns

• SANE_STATUS_GOOD - page is not blank
• SANE_STATUS_NO_DOCS - page is blank
• SANE_STATUS_NO_MEM - not enough memory
• SANE_STATUS_INVAL - invalid image parameters

sanei_magic_findTurn()

SANE_Status sanei_magic_findTurn	(	SANE_Parameters *	params,
		SANE_Byte *	buffer,
		int	dpiX,
		int	dpiY,
		int *	angle
	)

Determine coarse image rotation (90 degree increments)

Parameters

	params	describes image
	buffer	contains image data
	dpiX	horizontal resolution
	dpiY	vertical resolution
[out]	angle	amount of rotation recommended

Returns

• SANE_STATUS_GOOD - success
• SANE_STATUS_NO_MEM - not enough memory
• SANE_STATUS_INVAL - invalid image parameters

sanei_magic_turn()

SANE_Status sanei_magic_turn	(	SANE_Parameters *	params,
		SANE_Byte *	buffer,
		int	angle
	)

Coarse image rotation (90 degree increments)

Parameters

params	describes image
buffer	contains image data
angle	amount of rotation requested (multiple of 90)

Returns

• SANE_STATUS_GOOD - success
• SANE_STATUS_NO_MEM - not enough memory
• SANE_STATUS_INVAL - invalid image or angle parameters