クラス
struct	cv::softfloat

struct	cv::softdouble

関数
	cv::softfloat::softfloat ()
	Default constructor

	cv::softfloat::softfloat (const softfloat &c)
	Copy constructor

softfloat &	cv::softfloat::operator= (const softfloat &c)
	Assign constructor

static const softfloat	cv::softfloat::fromRaw (const uint32_t a)
	Construct from raw [詳解]

	cv::softfloat::softfloat (const uint32_t)
	Construct from integer

	cv::softfloat::softfloat (const uint64_t)

	cv::softfloat::softfloat (const int32_t)

	cv::softfloat::softfloat (const int64_t)

	cv::softfloat::softfloat (const float a)
	Construct from float

	cv::softfloat::operator softdouble () const
	Type casts

	cv::softfloat::operator float () const

softfloat	cv::softfloat::operator+ (const softfloat &) const
	Basic arithmetics

softfloat	cv::softfloat::operator- (const softfloat &) const

softfloat	cv::softfloat::operator* (const softfloat &) const

softfloat	cv::softfloat::operator/ (const softfloat &) const

softfloat	cv::softfloat::operator- () const

softfloat	cv::softfloat::operator% (const softfloat &) const
	Remainder operator [詳解]

softfloat &	cv::softfloat::operator+= (const softfloat &a)

softfloat &	cv::softfloat::operator-= (const softfloat &a)

softfloat &	*cv::softfloat::operator=** (const softfloat &a)

softfloat &	cv::softfloat::operator/= (const softfloat &a)

softfloat &	cv::softfloat::operator%= (const softfloat &a)

bool	cv::softfloat::operator== (const softfloat &) const
	Comparison operations [詳解]

bool	cv::softfloat::operator!= (const softfloat &) const

bool	cv::softfloat::operator> (const softfloat &) const

bool	cv::softfloat::operator>= (const softfloat &) const

bool	cv::softfloat::operator< (const softfloat &) const

bool	cv::softfloat::operator<= (const softfloat &) const

bool	cv::softfloat::isNaN () const
	NaN state indicator

bool	cv::softfloat::isInf () const
	Inf state indicator

bool	cv::softfloat::isSubnormal () const
	Subnormal number indicator

bool	cv::softfloat::getSign () const
	Get sign bit

softfloat	cv::softfloat::setSign (bool sign) const
	Construct a copy with new sign bit

int	cv::softfloat::getExp () const
	Get 0-based exponent

softfloat	cv::softfloat::setExp (int e) const
	Construct a copy with new 0-based exponent

softfloat	cv::softfloat::getFrac () const
	Get a fraction part [詳解]

softfloat	cv::softfloat::setFrac (const softfloat &s) const
	Construct a copy with provided significand [詳解]

static softfloat	cv::softfloat::zero ()
	Zero constant

static softfloat	cv::softfloat::inf ()
	Positive infinity constant

static softfloat	cv::softfloat::nan ()
	Default NaN constant

static softfloat	cv::softfloat::one ()
	One constant

static softfloat	cv::softfloat::min ()
	Smallest normalized value

static softfloat	cv::softfloat::eps ()
	Difference between 1 and next representable value

static softfloat	cv::softfloat::max ()
	Biggest finite value

static softfloat	cv::softfloat::pi ()
	Correct pi approximation

	cv::softdouble::softdouble ()
	Default constructor

	cv::softdouble::softdouble (const softdouble &c)
	Copy constructor

softdouble &	cv::softdouble::operator= (const softdouble &c)
	Assign constructor

static softdouble	cv::softdouble::fromRaw (const uint64_t a)
	Construct from raw [詳解]

	cv::softdouble::softdouble (const uint32_t)
	Construct from integer

	cv::softdouble::softdouble (const uint64_t)

	cv::softdouble::softdouble (const int32_t)

	cv::softdouble::softdouble (const int64_t)

	cv::softdouble::softdouble (const double a)
	Construct from double

	cv::softdouble::operator softfloat () const
	Type casts

	cv::softdouble::operator double () const

softdouble	cv::softdouble::operator+ (const softdouble &) const
	Basic arithmetics

softdouble	cv::softdouble::operator- (const softdouble &) const

softdouble	cv::softdouble::operator* (const softdouble &) const

softdouble	cv::softdouble::operator/ (const softdouble &) const

softdouble	cv::softdouble::operator- () const

softdouble	cv::softdouble::operator% (const softdouble &) const
	Remainder operator [詳解]

softdouble &	cv::softdouble::operator+= (const softdouble &a)

softdouble &	cv::softdouble::operator-= (const softdouble &a)

softdouble &	*cv::softdouble::operator=** (const softdouble &a)

softdouble &	cv::softdouble::operator/= (const softdouble &a)

softdouble &	cv::softdouble::operator%= (const softdouble &a)

bool	cv::softdouble::operator== (const softdouble &) const
	Comparison operations [詳解]

bool	cv::softdouble::operator!= (const softdouble &) const

bool	cv::softdouble::operator> (const softdouble &) const

bool	cv::softdouble::operator>= (const softdouble &) const

bool	cv::softdouble::operator< (const softdouble &) const

bool	cv::softdouble::operator<= (const softdouble &) const

bool	cv::softdouble::isNaN () const
	NaN state indicator

bool	cv::softdouble::isInf () const
	Inf state indicator

bool	cv::softdouble::isSubnormal () const
	Subnormal number indicator

bool	cv::softdouble::getSign () const
	Get sign bit

softdouble	cv::softdouble::setSign (bool sign) const
	Construct a copy with new sign bit

int	cv::softdouble::getExp () const
	Get 0-based exponent

softdouble	cv::softdouble::setExp (int e) const
	Construct a copy with new 0-based exponent

softdouble	cv::softdouble::getFrac () const
	Get a fraction part [詳解]

softdouble	cv::softdouble::setFrac (const softdouble &s) const
	Construct a copy with provided significand [詳解]

static softdouble	cv::softdouble::zero ()
	Zero constant

static softdouble	cv::softdouble::inf ()
	Positive infinity constant

static softdouble	cv::softdouble::nan ()
	Default NaN constant

static softdouble	cv::softdouble::one ()
	One constant

static softdouble	cv::softdouble::min ()
	Smallest normalized value

static softdouble	cv::softdouble::eps ()
	Difference between 1 and next representable value

static softdouble	cv::softdouble::max ()
	Biggest finite value

static softdouble	cv::softdouble::pi ()
	Correct pi approximation

CV_EXPORTS softfloat	cv::mulAdd (const softfloat &a, const softfloat &b, const softfloat &c)
	Fused Multiplication and Addition [詳解]

CV_EXPORTS softdouble	cv::mulAdd (const softdouble &a, const softdouble &b, const softdouble &c)

CV_EXPORTS softfloat	cv::sqrt (const softfloat &a)
	Square root

CV_EXPORTS softdouble	cv::sqrt (const softdouble &a)

template<typename _Tp >
static _Tp	cv::saturate_cast (softfloat a)
	Saturate casts

template<typename _Tp >
static _Tp	cv::saturate_cast (softdouble a)

template<>
uchar	cv::saturate_cast< uchar > (softfloat a)

template<>
uchar	cv::saturate_cast< uchar > (softdouble a)

template<>
schar	cv::saturate_cast< schar > (softfloat a)

template<>
schar	cv::saturate_cast< schar > (softdouble a)

template<>
ushort	cv::saturate_cast< ushort > (softfloat a)

template<>
ushort	cv::saturate_cast< ushort > (softdouble a)

template<>
short	cv::saturate_cast< short > (softfloat a)

template<>
short	cv::saturate_cast< short > (softdouble a)

template<>
int	cv::saturate_cast< int > (softfloat a)

template<>
int	cv::saturate_cast< int > (softdouble a)

template<>
int64_t	cv::saturate_cast< int64_t > (softfloat a)

template<>
int64_t	cv::saturate_cast< int64_t > (softdouble a)

template<>
unsigned	cv::saturate_cast< unsigned > (softfloat a)
	Saturate cast to unsigned integer and unsigned long long integer We intentionally do not clip negative numbers, to make -1 become 0xffffffff etc.

template<>
unsigned	cv::saturate_cast< unsigned > (softdouble a)

template<>
uint64_t	cv::saturate_cast< uint64_t > (softfloat a)

template<>
uint64_t	cv::saturate_cast< uint64_t > (softdouble a)

softfloat	cv::min (const softfloat &a, const softfloat &b)
	Min and Max functions

softdouble	cv::min (const softdouble &a, const softdouble &b)

softfloat	cv::max (const softfloat &a, const softfloat &b)

softdouble	cv::max (const softdouble &a, const softdouble &b)

softfloat	cv::abs (softfloat a)
	Absolute value

softdouble	cv::abs (softdouble a)

CV_EXPORTS softfloat	cv::exp (const softfloat &a)
	Exponent [詳解]

CV_EXPORTS softdouble	cv::exp (const softdouble &a)

CV_EXPORTS softfloat	cv::log (const softfloat &a)
	Natural logarithm [詳解]

CV_EXPORTS softdouble	cv::log (const softdouble &a)

CV_EXPORTS softfloat	cv::pow (const softfloat &a, const softfloat &b)
	Raising to the power [詳解]

CV_EXPORTS softdouble	cv::pow (const softdouble &a, const softdouble &b)

CV_EXPORTS softfloat	cv::cbrt (const softfloat &a)
	Cube root [詳解]

CV_EXPORTS softdouble	cv::sin (const softdouble &a)
	Sine [詳解]

CV_EXPORTS softdouble	cv::cos (const softdouble &a)
	Cosine [詳解]

変数
uint32_t	cv::softfloat::v

uint64_t	cv::softdouble::v

詳解

SoftFloat is a software implementation of floating-point calculations according to IEEE 754 standard. All calculations are done in integers, that's why they are machine-independent and bit-exact. This library can be useful in accuracy-critical parts like look-up tables generation, tests, etc. OpenCV contains a subset of SoftFloat partially rewritten to C++.

Types

There are two basic types: softfloat and softdouble. These types are binary compatible with float and double types respectively and support conversions to/from them. Other types from original SoftFloat library like fp16 or fp128 were thrown away as well as quiet/signaling NaN support, on-the-fly rounding mode switch and exception flags (though exceptions can be implemented in the future).

Operations

Both types support the following:

Construction from signed and unsigned 32-bit and 64 integers, float/double or raw binary representation
Conversions between each other, to float or double and to int using cvRound, cvTrunc, cvFloor, cvCeil or a bunch of saturate_cast functions
Add, subtract, multiply, divide, remainder, square root, FMA with absolute precision
Comparison operations
Explicit sign, exponent and significand manipulation through get/set methods, number state indicators (isInf, isNan, isSubnormal)
Type-specific constants like eps, minimum/maximum value, best pi approximation, etc.
min(), max(), abs(), exp(), log() and pow() functions

関数詳解

◆ cbrt()

CV_EXPORTS softfloat cv::cbrt ( const softfloat & a )

Cube root

Special cases:

cbrt(NaN) is NaN
cbrt(+/-Inf) is +/-Inf

◆ cos()

CV_EXPORTS softdouble cv::cos ( const softdouble & a )

Cosine

Special cases:

cos(Inf) or cos(NaN) is NaN
cos(x) == +/- 1 when cos(x) is close to +/- 1

◆ exp()

CV_EXPORTS softfloat cv::exp ( const softfloat & a )

Exponent

Special cases:

exp(NaN) is NaN
exp(-Inf) == 0
exp(+Inf) == +Inf

◆ fromRaw() [1/2]

static const softfloat cv::softfloat::fromRaw ( const uint32_t a )

inlinestatic

Construct from raw

Builds new value from raw binary representation

◆ fromRaw() [2/2]

static softdouble cv::softdouble::fromRaw ( const uint64_t a )

inlinestatic

Construct from raw

Builds new value from raw binary representation

◆ getFrac() [1/2]

softfloat cv::softfloat::getFrac ( ) const

inline

Get a fraction part

Returns a number 1 <= x < 2 with the same significand

◆ getFrac() [2/2]

softdouble cv::softdouble::getFrac ( ) const

inline

Get a fraction part

Returns a number 1 <= x < 2 with the same significand

◆ log()

CV_EXPORTS softfloat cv::log ( const softfloat & a )

Natural logarithm

Special cases:

log(NaN), log(x < 0) are NaN
log(0) == -Inf

◆ mulAdd()

CV_EXPORTS softfloat cv::mulAdd	(	const softfloat &	a,
		const softfloat &	b,
		const softfloat &	c
	)

Fused Multiplication and Addition

Computes (a*b)+c with single rounding

◆ operator%() [1/2]

softdouble cv::softdouble::operator% ( const softdouble & ) const

Remainder operator

A quote from original SoftFloat manual:

The IEEE Standard remainder operation computes the value a - n * b, where n is the integer closest to a / b. If a / b is exactly halfway between two integers, n is the even integer closest to a / b. The IEEE Standard’s remainder operation is always exact and so requires no rounding. Depending on the relative magnitudes of the operands, the remainder functions can take considerably longer to execute than the other SoftFloat functions. This is an inherent characteristic of the remainder operation itself and is not a flaw in the SoftFloat implementation.

◆ operator%() [2/2]

softfloat cv::softfloat::operator% ( const softfloat & ) const

Remainder operator

A quote from original SoftFloat manual:

The IEEE Standard remainder operation computes the value a - n * b, where n is the integer closest to a / b. If a / b is exactly halfway between two integers, n is the even integer closest to a / b. The IEEE Standard’s remainder operation is always exact and so requires no rounding. Depending on the relative magnitudes of the operands, the remainder functions can take considerably longer to execute than the other SoftFloat functions. This is an inherent characteristic of the remainder operation itself and is not a flaw in the SoftFloat implementation.

◆ operator==() [1/2]

bool cv::softdouble::operator== ( const softdouble & ) const

Comparison operations

Any operation with NaN produces false
- The only exception is when x is NaN: x != y for any y.
Positive and negative zeros are equal

◆ operator==() [2/2]

bool cv::softfloat::operator== ( const softfloat & ) const

Comparison operations

Any operation with NaN produces false
- The only exception is when x is NaN: x != y for any y.
Positive and negative zeros are equal

◆ pow()

CV_EXPORTS softfloat cv::pow	(	const softfloat &	a,
		const softfloat &	b
	)

Raising to the power

Special cases:

x**NaN is NaN for any x
( |x| == 1 )**Inf is NaN
( |x| > 1 )**+Inf or ( |x| < 1 )**-Inf is +Inf
( |x| > 1 )**-Inf or ( |x| < 1 )**+Inf is 0
x ** 0 == 1 for any x
x ** 1 == 1 for any x
NaN ** y is NaN for any other y
Inf**(y < 0) == 0
Inf ** y is +Inf for any other y
(x < 0)**y is NaN for any other y if x can't be correctly rounded to integer
0 ** 0 == 1
0 ** (y < 0) is +Inf
0 ** (y > 0) is 0

◆ setFrac() [1/2]

softdouble cv::softdouble::setFrac ( const softdouble & s ) const

inline

Construct a copy with provided significand

Constructs a copy of a number with significand taken from parameter

◆ setFrac() [2/2]

softfloat cv::softfloat::setFrac ( const softfloat & s ) const

inline

Construct a copy with provided significand

Constructs a copy of a number with significand taken from parameter

◆ sin()

CV_EXPORTS softdouble cv::sin ( const softdouble & a )

Sine

Special cases:

sin(Inf) or sin(NaN) is NaN
sin(x) == x when sin(x) is close to zero

クラス

関数

変数

詳解

Types

Operations

関数詳解

◆ cbrt()

◆ cos()

◆ exp()

◆ fromRaw() [1/2]

◆ fromRaw() [2/2]

◆ getFrac() [1/2]

◆ getFrac() [2/2]

◆ log()

◆ mulAdd()

◆ operator%() [1/2]

◆ operator%() [2/2]

◆ operator==() [1/2]

◆ operator==() [2/2]

◆ pow()

◆ setFrac() [1/2]

◆ setFrac() [2/2]

◆ sin()