jp2

package

v1.0.1 Latest Latest Go to latest Published: Jun 30, 2026 License: MIT Imports: 5 Imported by: 0

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Valid go.mod file
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Repository

github.com/0verkilll/jpeg

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Documentation ¶

Index ¶

Constants
Variables
type Box
type Builder
- func NewBuilder() *Builder
type ImageInfo
type Reader
- func NewReader(data []byte) *Reader
type Writer
- func NewWriter() *Writer

Constants ¶

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const (
	BoxTypeSignature   = 0x6A502020 // 'jP  ' - JP2 Signature
	BoxTypeFileType    = 0x66747970 // 'ftyp' - File Type
	BoxTypeJP2Header   = 0x6A703268 // 'jp2h' - JP2 Header
	BoxTypeImageHeader = 0x69686472 // 'ihdr' - Image Header
	BoxTypeColourSpec  = 0x636F6C72 // 'colr' - Colour Specification
	BoxTypeCodestream  = 0x6A703263 // 'jp2c' - Contiguous Codestream
)

JP2 box types

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const (
	ColourMethodEnumCS        = 1 // Enumerated Colourspace
	ColourMethodRestrictedICC = 2 // Restricted ICC Profile
)

Colour specification method

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const (
	ColourSpaceUnknown = 0
	ColourSpaceSRGB    = 16 // sRGB
	ColourSpaceGray    = 17 // Greyscale
	ColourSpaceSYCC    = 18 // sYCC (YCbCr)
)

Enumerated colourspaces

Variables ¶

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var (
	ErrInvalidSignature  = errors.New("invalid JP2 signature")
	ErrMissingHeader     = errors.New("missing JP2 header")
	ErrInvalidBox        = errors.New("invalid box structure")
	ErrMissingCodestream = errors.New("missing codestream")
)

Errors

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var BrandJP2 = [4]byte{'j', 'p', '2', ' '}

BrandJP2 is the JP2 file type brand identifier.

View Source

var Signature = [4]byte{0x0D, 0x0A, 0x87, 0x0A}

Signature contains the signature box contents for JP2 files

Functions ¶

This section is empty.

Types ¶

type Box ¶

type Box struct {
	Type     uint32
	Data     []byte
	Children []*Box // For superboxes like jp2h
}

Box represents a JP2 box structure

type Builder ¶

type Builder struct {
	// contains filtered or unexported fields
}

Builder builds a complete JP2 file

func NewBuilder ¶

func NewBuilder() *Builder

NewBuilder creates a new JP2 builder

func (*Builder) Build ¶

func (b *Builder) Build(codestream []byte) ([]byte, error)

Build creates the JP2 file with the given codestream

func (*Builder) SetBitDepth ¶

func (b *Builder) SetBitDepth(bpc uint8, signed bool) *Builder

SetBitDepth sets the bits per component

func (*Builder) SetColourSpace ¶

func (b *Builder) SetColourSpace(cs int) *Builder

SetColourSpace sets the colour space

func (*Builder) SetComponents ¶

func (b *Builder) SetComponents(numComps uint16) *Builder

SetComponents sets the number of components

func (*Builder) SetImageSize ¶

func (b *Builder) SetImageSize(width, height uint32) *Builder

SetImageSize sets the image dimensions

type ImageInfo ¶

type ImageInfo struct {
	Width       uint32
	Height      uint32
	NumComps    uint16
	BitsPerComp uint8
	Signed      bool
	ColourSpace int
}

ImageInfo contains image information for JP2 header

type Reader ¶

type Reader struct {
	// contains filtered or unexported fields
}

Reader reads JP2 container format

func NewReader ¶

func NewReader(data []byte) *Reader

NewReader creates a new JP2 reader

func (*Reader) ExtractCodestream ¶

func (r *Reader) ExtractCodestream() ([]byte, error)

ExtractCodestream extracts the codestream from the JP2 file

func (*Reader) GetImageInfo ¶

func (r *Reader) GetImageInfo() (*ImageInfo, error)

GetImageInfo extracts image information from the JP2 header

func (*Reader) ReadBox ¶

func (r *Reader) ReadBox() (*Box, error)

ReadBox reads the next box from the stream

func (*Reader) Verify ¶

func (r *Reader) Verify() error

Verify verifies that data is a valid JP2 file

type Writer ¶

type Writer struct {
	// contains filtered or unexported fields
}

Writer writes JP2 container format

func NewWriter ¶

func NewWriter() *Writer

NewWriter creates a new JP2 writer

func (*Writer) Bytes ¶

func (w *Writer) Bytes() []byte

Bytes returns the written data

func (*Writer) Reset ¶

func (w *Writer) Reset()

Reset resets the writer for reuse

func (*Writer) WriteBox ¶

func (w *Writer) WriteBox(boxType uint32, data []byte)

WriteBox writes a generic box

func (*Writer) WriteJP2 ¶

func (w *Writer) WriteJP2(info *ImageInfo, codestream []byte) error

WriteJP2 writes a complete JP2 file with the given image info and codestream

func (*Writer) WriteTo ¶

func (w *Writer) WriteTo(writer io.Writer) (int64, error)

WriteTo writes to an io.Writer

Source Files ¶

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