Functions to create and process image structures. More...

Functions
Image *	imgNew (unsigned int width, unsigned int height, unsigned short depth)
	Creates a new image. More...

Image *	imgFromBitmap (const char *filename)
	Loads an image from a BMP image file. More...

Image *	imgFromPPM (const char *filename)
	Loads an image from a PPM image file. More...

Image *	imgFromFile (const char *filename)

int	imgSavePPM (Image img, char fname)

int	imgSavePAM (Image img, char fname)

int	imgSaveRAW (Image img, char fname)
	Save RAW file. More...

Image *	imgCopy (Image *img)
	Creates a copy of an Image. More...

void	imgScale (Image *img, unsigned int sfactor)
	Scales an image.

Image *	imgCrop (Image *img, int x1, int y1, int x2, int y2)
	Crops an image. More...

Image *	imgCreateGaussian (int dim, float sig)

Image *	imgConvolution (Image img1, Image img2, Image *res)
	Image convolution. More...

int	imgFindPattern (Image img, Image pat, int best_x, int best_y)
	Searches image for a pattern. More...

int	imgFindPatternArea (Image img, Image pat, int x1, int y1, int x2, int y2, int best_x, int best_y)
	Searches image area for a pattern. More...

void	imgDestroy (Image *img)
	Destroys the image.

void	imgMakeSymmetricX (Image *img)

void	imgMakeSymmetricY (Image *img)

void	imgMakeSymmetric (Image *img)

int	imgGetSymmetryError (Image *img, int x, int y, int radius)
	Evaluates simmetry error at location. More...

Image *	imgPatternDifference (Image img, Image pat, Image *res, int x1, int y1, int x2, int y2)
	Searches image for a pattern. More...

int	imgGetPixelDifference (unsigned char p1, unsigned char p2)

int	imgGetSumArea (Image *img, int x1, int y1, int x2, int y2)
	Evaluates the addition of pixel components. More...

float	imgGetMeanArea (Image *img, int x1, int y1, int x2, int y2)
	Evaluates the pixel component mean value. More...

float	imgGetMean (Image *img)
	Evaluates the pixel component mean value. More...

unsigned int	imgGetWidth (Image *img)

unsigned int	imgGetHeight (Image *img)

void	imgSetPixel (Image img, unsigned int x, unsigned int y, unsigned char pdata)

void	imgSetPixelRGB (Image *img, unsigned int x, unsigned int y, unsigned char r, unsigned char g, unsigned char b)

void	imgSetPixelRGBA (Image *img, unsigned int x, unsigned int y, unsigned char r, unsigned char g, unsigned char b, unsigned char a)

unsigned char *	imgGetPixel (Image *img, unsigned int x, unsigned int y)
	Gets pixel data. More...

unsigned char *	imgPixel (Image *img, unsigned int x, unsigned int y)

void	MarkImagePositionRGB (Image *img, int x, int y, unsigned char r, unsigned char g, unsigned char b)

void	MarkImagePosition (Image *img, int x, int y)

int	imgGetSymmetricError (Image *img, int x1, int x2, int y1, int y2)

Detailed Description

Functions to create and process image structures.

Function Documentation

◆ imgConvolution()

Image * imgConvolution	(	Image *	img1,
		Image *	img2,
		Image *	res
	)

Image convolution.

Performs a convolution beteween Image img1 and Image img2. Convolution result is stored in preallocated Image res. Image res should have dimensions and depth matching Image img1. If res equals NULL, a new Image is allocated. Implementation is optimized for img1 larger than img2. This is usually adequated for processing Image img1 through kernel Image img2. Image img2 should have odd dimensions. Image img2 must use a pixel depth of 8 bits or the same pixel depth as Image img1.

Parameters

img	Location of Image structure
x	Number of pixel columns
y	Number of pixel rows

Returns: The convolution resulting Image.

◆ imgCopy()

Image * imgCopy ( Image * img )

Creates a copy of an Image.

Creates a new image storing a copy of an original Image. Created Image can then be released by calling the imgDestroy() function.

Parameters

img	the source Image (Image to crop)

Returns: The address of the new copied Image

◆ imgCrop()

Image * imgCrop	(	Image *	img,
		int	x1,
		int	y1,
		int	x2,
		int	y2
	)

Crops an image.

Copies a rectangular area to a new Image. Image is created with undefined colors. Image can then be released by calling the imgDestroy() function.

Parameters

img	the source Image (Image to crop)
x1	the column number of first vertex
y1	the row number of first vertex
x2	the column number of second vertex
y2	the row number of second vertex

Returns: The address of the new cropped Image

◆ imgFindPattern()

int imgFindPattern	(	Image *	img,
		Image *	pat,
		int *	best_x,
		int *	best_y
	)

Searches image for a pattern.

Searches the full specified area from Image img for ocurrences of pattern Image pat. Selectes and informs the location of the best matching pattern.

Parameters

img	Image to be searched.
pat	Image pattern to search for.
best_x	location to store the column number of the selected location.
best_y	location to store the row number of the selected location.

Returns: The matching error for the selected location.

◆ imgFindPatternArea()

int imgFindPatternArea	(	Image *	img,
		Image *	pat,
		int	x1,
		int	y1,
		int	x2,
		int	y2,
		int *	best_x,
		int *	best_y
	)

Searches image area for a pattern.

Searches the full specified area from Image img for ocurrences of pattern Image pat. Selectes and informs the location of the best matching pattern.

Parameters

img	Image to be searched.
pat	Image pattern to search for.
x1	the column number of the top left corner of the image area to be searched
y1	the row number of the top left corner of the image area to be searched
x2	the column number of the bottom right corner of the image area
y2	the row number of the bottom right corner of the image area to be searched
best_x	location to store the column number of the selected location.
best_y	location to store the row number of the selected location.

Returns: The matching error for the selected location.

◆ imgFromBitmap()

Image * imgFromBitmap ( const char * filename )

Loads an image from a BMP image file.

Creates a new Image using the data read from the specified BMP image file. Image can then be released by calling imgDestroy() function.

Parameters

filename the name of the BMP image file

Returns: The address of the new loaded Image

◆ imgFromPPM()

Image * imgFromPPM ( const char * filename )

Loads an image from a PPM image file.

Creates a new Image using the data read from the specified PPM image file. Image can then be released by calling imgDestroy() function.

Parameters

filename the name of the PPM image file

Returns: The address of the new loaded Image

◆ imgGetMean()

float imgGetMean ( Image * img )

Evaluates the pixel component mean value.

Evaluates the mean value from all (color) components and all pixels within the Image img.

Parameters

img	Image to be processed.

Returns: the calculated mean value as a float

◆ imgGetMeanArea()

float imgGetMeanArea	(	Image *	img,
		int	x1,
		int	y1,
		int	x2,
		int	y2
	)

Evaluates the pixel component mean value.

Evaluates the mean value from all (color) components and all pixel within the specified area of the Image img.

Parameters

img	Image to be processed.
x1	the column number of the top left corner of the image area to be processed
y1	the row number of the top left corner of the image area to be processed
x2	the column number of the bottom right corner of the image area to be processed
y2	the row number of the bottom right corner of the image area to be processed

Returns: the calculated mean value as a float

◆ imgGetPixel()

unsigned char * imgGetPixel	(	Image *	img,
		unsigned int	x,
		unsigned int	y
	)

Gets pixel data.

Returns a pointer to the pixel data

Parameters

img	Image structure location
x	pixel column number
y	pixel row number

Returns: A pointer to the pixel data array

◆ imgGetSumArea()

int imgGetSumArea	(	Image *	img,
		int	x1,
		int	y1,
		int	x2,
		int	y2
	)

Evaluates the addition of pixel components.

Evaluates the total addition of all (color) components' values from all pixels within the specified area of the Image img.

Parameters

img	Image to be processed.
x1	the column number of the top left corner of the image area to be processed
y1	the row number of the top left corner of the image area to be processed
x2	the column number of the bottom right corner of the image area to be processed
y2	the row number of the bottom right corner of the image area to be processed

Returns: The calculated total value as an int

◆ imgGetSymmetryError()

int imgGetSymmetryError	(	Image *	img,
		int	x,
		int	y,
		int	radius
	)

Evaluates simmetry error at location.

Evaluates the simmetry error of an image's square area. Computed error will be zero if the squre area is fully simmetric along the X and Y axis.

Parameters

img	Image to be processed
x	the column number of the image area to be evaluated
y	the row number of the image area to be evaluated
radius	the half side dimension of the square area

Returns: The total simmetry error

◆ imgNew()

Image * imgNew	(	unsigned int	width,
		unsigned int	height,
		unsigned short	depth
	)

Creates a new image.

Allocates a memory block to store an Image structure. Image is created with undefined colors. Image can then be released by calling imgDestroy() function.

Parameters

width	the number of columns
height	the number of rows
depth	the pixel size in bits

Returns: The address of the new allocated Image

◆ imgPatternDifference()

Image * imgPatternDifference	(	Image *	img,
		Image *	pat,
		Image *	res,
		int	x1,
		int	y1,
		int	x2,
		int	y2
	)

Searches image for a pattern.

Searches full specified area from Image img for ocurrences of pattern Image pat. Produces resulting Image res with calculated differences.

Parameters

img	Image to be searched.
pat	Image pattern to search for.
res	Previously allocated Image where resulting differences will be stored. If `res` equals NULL, a new Image is created.
x1	the column number of the top left corner of the image area to be searched
y1	the row number of the top left corner of the image area to be searched
x2	the column number of the bottom right corner of the image area
y2	the row number of the bottom right corner of the image area to be searched

Returns: the address of the resulting Image

◆ imgSaveRAW()

int imgSaveRAW	(	Image *	img,
		char *	fname
	)

Save RAW file.

Creates (or overwrites) a new file to store Image img. Image is stored in RAW format, without any header or metadata.

Parameters

img	Image to be stored.
fname	Name of the destination file.

Returns: 0 on success and 1 on error.