sanei_magic.h File Reference

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

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Functions
void	sanei_magic_init (void)
	Initialize sanei_magic.
SANE_Status	sanei_magic_despeck (SANE_Parameters *params, SANE_Byte *buffer, SANE_Int diam)
	Update the image buffer, replacing dots with surrounding background color.
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.
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.
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.
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.

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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)

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

---

Function Documentation

void sanei_magic_init

(

void

)

Initialize sanei_magic.

Call this before any other sanei_magic function.

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

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

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

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

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