Description

Package which provides functions to create Look Up Tables for various functions The generated Look Up Table can be placed in a lookup_table entity.

See also: lookup_table

Package Body >> curves_pkg

Functions
array_pixel	create_straight_lut ( size: in integer , c: in real 1.0 )
array_pixel	create_negated_lut ( size: in integer )
array_pixel	create_sigmoid_lut ( size: in integer , c: in real 1.0 )
array_pixel	create_gamma_lut ( size: in integer gamma: in real 1.0 c: in real 1.0 )
array_pixel	create_sine_lut ( size: in integer , c: in real 1.0 )

Procedures
	verify_valid_value( variable value: in real ,constant wordsize: in integer )
	report_lut_value( variable value: in real ,constant index: in integer )

Libraries
ieee

Use Clauses
std_logic_1164
numeric_std
math_real

Constants
wordsize	integer := 8
	Bit depth of pixels.

Types
array_pixel	array ( natural range <> ) of std_logic_vector ( wordsize - 1 downto 0 )
	array of std_logic_vectors

Member Function Documentation

§ create_gamma_lut()

array_pixel create_gamma_lut	(	size in integer ,
		gamma in real 1 . 0 ,
		c in real 1 . 0
	)

Function

Function to create Look up table for a gamma function The gamma function is

$p_{out}=c*p_{max}*(\frac{p_{in}}{p_{max}})^{\gamma}$

Parameters

[in]	size	Number of elements to create
[in]	gamma	Gamma factor
[in]	c	Amplification factor

§ create_negated_lut()

array_pixel create_negated_lut	(		size in integer
	)

Function

Function to create Look up table for a negated line The negate function is

$p_{out}=p_{max}-p_{in}$

Parameters

[in]

size

Number of elements to create

§ create_sigmoid_lut()

array_pixel create_sigmoid_lut	(	size in integer ,
		c in real 1 . 0
	)

Function

Function to create Look up table for a sigmoid function The sigmoid function is

$p_{out}=\frac{p_{max}}{1+\exp({-c/p_{max}*(p_{in}-p_{max})})}$

Parameters

[in]	size	Number of elements to create
[in]	c	Amplification factor

§ create_sine_lut()

array_pixel create_sine_lut	(	size in integer ,
		c in real 1 . 0
	)

Function

Function to create Look up table for a sine function The sine function is

$p_{out}=p_{max} * sin^c\left (\frac{\pi*x}{width} \right)$

Parameters

[in]	size	Number of elements to create
[in]	c	Order

§ create_straight_lut()

array_pixel create_straight_lut	(	size in integer ,
		c in real 1 . 0
	)

Function

Function to create Look up table for a straight line Used for testing purposes, creates a straight line. The straight function is

$p_{out}=c*p_{in}$

Parameters

[in]	size	Number of elements to create
[in]	c	Amplification factor

§ report_lut_value()

report_lut_value	(	variable	value in real ,
		constant	index in integer
	)

Procedure

Procedure to pretty print out a LUT value

Parameters

[in]	value	Value to be printed
[in]	index	Index to print

§ verify_valid_value()

verify_valid_value	(	variable	value in real ,
		constant	wordsize in integer
	)

Procedure

Procedure to assert that value can be represented in bit range

Parameters

[in]	value	Value to compare
[in]	wordsize	Bit depth

Member Data Documentation

§ array_pixel

array_pixel array ( natural range <> ) of std_logic_vector ( wordsize - 1 downto 0 )

Type

array of std_logic_vectors

§ ieee

ieee

Library

§ math_real

math_real

Package

§ numeric_std

numeric_std

Package

§ std_logic_1164

std_logic_1164

Package

§ wordsize

wordsize integer := 8

Constant

Bit depth of pixels.

The documentation for this class was generated from the following file:

/home/ben/Programming/VHDL/realtimestagram/src/common/src/curves_pkg.vhd

Description

Functions

Procedures

Libraries

Use Clauses

Constants

Types

Member Function Documentation

§ create_gamma_lut()

§ create_negated_lut()

§ create_sigmoid_lut()

§ create_sine_lut()

§ create_straight_lut()

§ report_lut_value()

§ verify_valid_value()

Member Data Documentation

§ array_pixel

§ ieee

§ math_real

§ numeric_std

§ std_logic_1164

§ wordsize