Jp2ImageEncoder Class Reference

Converts image type ImageType::JPG2000. More...

#include <ImageEncoder.h>

Collaboration diagram for Jp2ImageEncoder:

Public Member Functions
	Jp2ImageEncoder ()
	Construct a new Jpeg 2000 Image Encoder object The default compression ratio is 4:1.
void	SetCompressionRatio (int ratio)
	Set compression ratio.
int	GetCompressionRatio () const
	Provides compression ratio.
bool	IsLossy () const
	Check if encoder setup is lossy.
bool	IsLossless () const
	Check if encoder setup is lossless.
void	Accept (ImageEncoderVisitor &visitor) const final
	Allow visitor to visit concrete type of encoder.
std::vector< uint8_t >	Encode (const RawImage &raw) const final
	Saves given RawImage as formatted image.

Static Public Member Functions
static std::shared_ptr< ImageEncoder >	Create (ImageType type)
	Create concrete default encoder for given type.

Detailed Description

Converts image type ImageType::JPG2000.

Member Function Documentation

Accept()

void Accept ( ImageEncoderVisitor & visitor ) const

inlinefinalvirtual

Allow visitor to visit concrete type of encoder.

Parameters

visitor

ImageEncoderVisitor to call

Implements ImageEncoder.

Create()

std::shared_ptr< ImageEncoder > Create ( ImageType type )

inlinestaticinherited

Create concrete default encoder for given type.

Parameters

type

ImageType

Exceptions

EnrollmentException

when image type is unknown

Returns

ImageEncoder

References ImageType::BMP, ImageType::IRAW, ImageType::JPG, ImageType::JPG2000, ImageType::PNG, ImageType::TIFF, ImageException::UNKNOWN_IMAGE, ImageType::WEBP, and ImageType::WSQ.

Referenced by Image::Decode(), and ImageFileSaver::Save().

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Encode()

std::vector< uint8_t > Encode ( const RawImage & raw ) const

inlinefinalvirtualinherited

Saves given RawImage as formatted image.

Parameters

raw

RawImage

Returns

encoded image

Exceptions

ImageException	when it is not possible to encode image
InvalidImageArgumentException	when image is empty

Implements ImageEncoder.

GetCompressionRatio()

int GetCompressionRatio ( ) const

inline

Provides compression ratio.

Returns

compression ratio, the value 1 has meaning lossless compression

IsLossless()

bool IsLossless ( ) const

inline

Check if encoder setup is lossless.

Returns

true lossless encoding

false lossy encoding

IsLossy()

bool IsLossy ( ) const

inline

Check if encoder setup is lossy.

Returns

true lossy encoding

false lossless encoding

SetCompressionRatio()

void SetCompressionRatio ( int ratio )

inline

Set compression ratio.

In JPEG2000, the compression ratio is defined as the ratio of the size of the uncompressed, raw image to the size of the compressed image. \( raw\_size = width * height * number\_of\_channels * bit\_depth /8 \) where bit_depth is number of bits in channel (e.g. 8,16). For example, a compression ratio of 20:1 indicates that the compressed image is 1/20th the size of the raw image. Be aware that even if compression ratio is 1 (lossless) the image will not have raw_size because of used compaction.

To get for example half (ratio 2:1) of image size (the encoded lossless size) use formula \( raw\_size / lossless\_encoded\_jp2\_size * 2 \). The size will be closed to half due to additional size of JP2 overhead.

Parameters

ratio

specifies compression ratio ratio:1. It means that image size will be 1/ratio of uncompressed, raw image size. valid range is <1,1000>. The value 1 mean no compression, lossless.

Exceptions

EnrollmentInvalidArgumentException

if the bitrate is not in the valid range <1,1000>.

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

• Image/ImageEncoder.h