DD::Image::Linear Class Reference

List of all members.

Static Public Member Functions
static float	from_byte (float f)
static void	from_byte (float *, const uchar *, int W, int delta=1)
static void	from_short (float *, const U16 *, int W, int bits=16, int delta=1)
static void	from_float (float *, const float *, int W, int delta=1)
static float	to_byte (float f)
static void	to_byte (uchar *, const float *, int W, int delta=1)
static void	to_short (U16 *, const float *, int W, int bits=16, int delta=1)
static void	to_float (float *, const float *, int W, int delta=1)
static void	to_float_cust (float *dst, const float *src, int W, unsigned int destDelta=1, unsigned int srcDelta=1)
static float	fromFloat (float v)
static float	fromFloatFast (float v)
static float	toFloat (float v)
static float	toFloatFast (float v)

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Detailed Description

This class is designed to resemble the interface to the class LUT, but simply multiplies or divides by 255. This can be done more efficiently than the lookup tables in the class LUT, which was designed for gamma functions that take longer to calculate.

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Member Function Documentation

void Linear::from_byte	(	float *	buf,
		const uchar *	from,
		int	W,
		int	delta = 1
	)		[static]

Converts W bytes to float by dividing them by 255. delta is the distance between the source bytes to allow them to be in an interlaced buffer.

void Linear::from_short	(	float *	buf,
		const U16 *	from,
		int	W,
		int	bits = 16,
		int	delta = 1
	)		[static]

Converts W 16-bit samples to float by dividing them by 2^n-1. delta is the distance between the source words to allow them to be in an interlaced buffer.

void Linear::to_byte	(	uchar *	buf,
		const float *	from,
		int	W,
		int	delta = 1
	)		[static]

Converts W floats to bytes by doing clamp(float)*255. Error diffusion is applied so that a much smoother and more accurate representation of the original values is stored, getting rid of posterizing effects.

W is the number of pixels to convert. delta is the distance between the output bytes (useful for interlacing them into a buffer for screen display).

The input and output buffers must not overlap in memory.

References fast_rint().

void Linear::to_short	(	U16 *	buf,
		const float *	from,
		int	W,
		int	bits = 16,
		int	delta = 1
	)		[static]

Converts W floats to clamp(float)*(2^n-1) and stores the result in buf. delta is the distance apart to store the results, allowing the output buffer to be interlaced.

This should do error diffusion but that is not yet implemented.

References fast_rint().