FRIF::Image Struct Reference

Data and metadata for an image. More...

#include <common.h>

Public Types
enum class	BitsPerPixel : uint8_t { Eight = 8 , Sixteen = 16 , TwentyFour = 24 , FortyEight = 48 }
	Number of bits comprising a single image pixel. More...
enum class	BitsPerChannel : uint8_t { Eight = 8 , Sixteen = 16 }
	Number of bits comprising a single color channel of a single pixel. More...
enum class	Colorspace { Grayscale , RGB }
using	BPP = BitsPerPixel
using	BPC = BitsPerChannel

Public Member Functions
	Image ()
	Image (const uint8_t identifier, const uint16_t width, const uint16_t height, const uint16_t ppi, const Colorspace colorspace, const BitsPerChannel bpc, const BitsPerPixel bpp, const std::vector< std::byte > &pixels)
	Image constructor.
void	sanityCheck () const
	Validate that the properties of this Image appear to correspond to valid image data.

Static Public Member Functions
static BitsPerPixel	toBitsPerPixel (const std::underlying_type_t< BitsPerPixel > i)
	Convert integer to enumerated type.
static BitsPerChannel	toBitsPerChannel (const std::underlying_type_t< BitsPerChannel > i)
	Convert integer to enumerated type.

Public Attributes
uint8_t	identifier {}
	An identifier for this image.
uint16_t	width {}
	Width of the image.
uint16_t	height {}
	Height of the image.
uint16_t	ppi {}
	Resolution of the image in pixels per inch.
Colorspace	colorspace {Colorspace::Grayscale}
	Representation of color in each byte within pixels.
BitsPerChannel	bpc {BitsPerChannel::Eight}
	Number of bits used by each color component.
BitsPerPixel	bpp {BitsPerPixel::Eight}
	Number of bits comprising a single pixel.
std::vector< std::byte >	pixels {}
	Raw pixel data of image.

Detailed Description

Data and metadata for an image.

Definition at line 57 of file common.h.

Member Typedef Documentation

BPP

using FRIF::Image::BPP = BitsPerPixel

Definition at line 67 of file common.h.

BPC

using FRIF::Image::BPC = BitsPerChannel

Definition at line 95 of file common.h.

Member Enumeration Documentation

BitsPerPixel

enum class FRIF::Image::BitsPerPixel : uint8_t

strong

Number of bits comprising a single image pixel.

Enumerator
Eight
Sixteen
TwentyFour
FortyEight

Definition at line 60 of file common.h.

BitsPerChannel

enum class FRIF::Image::BitsPerChannel : uint8_t

strong

Number of bits comprising a single color channel of a single pixel.

Enumerator
Eight
Sixteen

Definition at line 90 of file common.h.

Colorspace

enum class FRIF::Image::Colorspace

strong

Enumerator
Grayscale	Single channel (shades of gray).
RGB	Three channels, with equal bit widths representing red, green, and blue, in order.

Definition at line 114 of file common.h.

Constructor & Destructor Documentation

Image() [1/2]

FRIF::Image::Image ( )

default

Image() [2/2]

FRIF::Image::Image	(	const uint8_t	identifier,
		const uint16_t	width,
		const uint16_t	height,
		const uint16_t	ppi,
		const Colorspace	colorspace,
		const BitsPerChannel	bpc,
		const BitsPerPixel	bpp,
		const std::vector< std::byte > &	pixels )

Image constructor.

Parameters

identifier	An identifier for this image. Used to link Image to TemplateData and Correspondence.
width	Width of the image in pixels.
height	Height of the image in pixels.
ppi	Resolution of the image in pixels per inch.
colorspace	Representation of color in each byte within pixels.
bpc	Number of bits used by each color component.
bpp	Number of bits comprising a single pixel.
pixels	width * height * (bpp / bpc) bytes of image data, with pixels.front() representing the first byte of the top-left pixel, and pixels.back() representing the last byte of the bottom-right pixel. It is decompressed big endian image data, canonically coded as defined in ISO/IEC 19794-4:2005, section 6.2. For example, the value 0xFF00 when bpc is BPC::Sixteen, bpp is BPP::Sixteen and colorspace is Colorspace::Grayscale is significantly closer to white than it is to black.

Note

You may call sanityCheck on this object to have some confidence that the image properties make sense.

Definition at line 74 of file libfrifte_common.cpp.

Member Function Documentation

toBitsPerPixel()

FRIF::Image::BitsPerPixel FRIF::Image::toBitsPerPixel ( const std::underlying_type_t< BitsPerPixel > i )

static

Convert integer to enumerated type.

Parameters

i	Integer version of enumerated type.

Returns

Enumerated value of i.

Exceptions

Cannot

map i to valid enumerated value.

Definition at line 96 of file libfrifte_common.cpp.

toBitsPerChannel()

FRIF::Image::BitsPerChannel FRIF::Image::toBitsPerChannel ( const std::underlying_type_t< BitsPerChannel > i )

static

Convert integer to enumerated type.

Parameters

i	Integer version of enumerated type.

Returns

Enumerated value of i.

Exceptions

Cannot

map i to valid enumerated value.

Definition at line 115 of file libfrifte_common.cpp.

sanityCheck()

void FRIF::Image::sanityCheck

(

)

const

Validate that the properties of this Image appear to correspond to valid image data.

Exceptions

std::logic_error

Some combination of properties appears invalid.

Definition at line 130 of file libfrifte_common.cpp.

Member Data Documentation

identifier

uint8_t FRIF::Image::identifier {}

An identifier for this image.

Used to link Image to EFS, TemplateData, and Correspondence.

Definition at line 187 of file common.h.

width

uint16_t FRIF::Image::width {}

Width of the image.

Definition at line 189 of file common.h.

height

uint16_t FRIF::Image::height {}

Height of the image.

Definition at line 191 of file common.h.

ppi

uint16_t FRIF::Image::ppi {}

Resolution of the image in pixels per inch.

Definition at line 193 of file common.h.

colorspace

Colorspace FRIF::Image::colorspace {Colorspace::Grayscale}

Representation of color in each byte within pixels.

Definition at line 195 of file common.h.

bpc

BitsPerChannel FRIF::Image::bpc {BitsPerChannel::Eight}

Number of bits used by each color component.

Definition at line 197 of file common.h.

bpp

BitsPerPixel FRIF::Image::bpp {BitsPerPixel::Eight}

Number of bits comprising a single pixel.

Definition at line 199 of file common.h.

pixels

std::vector<std::byte> FRIF::Image::pixels {}

Raw pixel data of image.

width * height * (bpp / bpc) bytes of image data, with pixels .front() representing the first byte of the top-left pixel, and pixels .back() representing the last byte of the bottom-right pixel. It is decompressed big endian image data, canonically coded as defined in ISO/IEC 19794-4:2005, section 6.2. For example, the value 0xFF00 when bpc is BPC::Sixteen, bpp is BPP::Sixteen and colorspace is Colorspace::Grayscale is significantly closer to white than it is to black.

Note

To pass pixels to a C-style array, invoke pixel's data() method (pixels.data()). You may safely reinterpret_cast this value to std::vector<uint8_t> if needed (e.g., to obtain a uint8_t* from data()).

Definition at line 221 of file common.h.

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The documentation for this struct was generated from the following files:

• common.h
• libfrifte_common.cpp