png

package
v0.0.0-...-4c07360 Latest Latest
Warning

This package is not in the latest version of its module.

 Go to latest Published: Aug 26, 2022 License: MIT Imports: 10 Imported by: 0

Documentation

Index

Constants

View Source 
const (
	// Critical Chunks
	IHDR string = "IHDR"
	PLTE string = "PLTE"
	IDAT string = "IDAT"
	IEND string = "IEND"

	Byte         uint32 = 1
	Kibibyte            = 1024 * Byte
	Mebibyte            = 1024 * Kibibyte
	Gibibyte            = 1024 * Mebibyte
	MaxChunkSize        = 100 * Mebibyte

	Greyscale          = byte(0)
	TrueColor          = byte(2)
	IndexedColor       = byte(3)
	GreyscaleWithAlpha = byte(4)
	TrueColorWithAlpha = byte(6)
)
View Source 
const (
	None    = byte(0)
	Sub     = byte(1)
	Up      = byte(2)
	Average = byte(3)
	Paeth   = byte(4)
)

Variables

This section is empty.

Functions

func Decompress 

func Decompress(chunk_map ChunkMap) ([]byte, error)

func Unfilter 

func Unfilter(filtered_bytes []byte, ihdr *IHDRChunk) ([][]byte, error)

Types

type Chunk 

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

func (*Chunk) Iscritical 

func (self *Chunk) Iscritical() bool

func (*Chunk) Reader 

func (self *Chunk) Reader() io.Reader

type ChunkMap 

type ChunkMap map[string][]Chunk

func ReadChunks 

func ReadChunks(file *os.File) (ChunkMap, error)

func (ChunkMap) IHDR 

func (self ChunkMap) IHDR() (*IHDRChunk, error)

func (ChunkMap) PLTE 

func (self ChunkMap) PLTE() (*Palette, error)

type Filter 

type Filter interface {
	Process([]byte, [][]byte) ([]byte, error)
}

type GrayScaleImageBuilder 

type GrayScaleImageBuilder[T Uint] struct {
	IHDR *IHDRChunk
}

func (*GrayScaleImageBuilder[T]) BuildPixels 

func (self *GrayScaleImageBuilder[T]) BuildPixels(data [][]byte) (*ImageData, error)

type GrayscalePixel 

type GrayscalePixel[T Uint] struct {
	// contains filtered or unexported fields
}

func CreateGrayscalePixel 

func CreateGrayscalePixel[T Uint](g T) *GrayscalePixel[T]

func CreateGrayscaleWithAlphaPixel 

func CreateGrayscaleWithAlphaPixel[T Uint](g T, a T) *GrayscalePixel[T]

func (*GrayscalePixel[T]) Uint16 

func (self *GrayscalePixel[T]) Uint16() []uint16

type GrayscaleReader 

type GrayscaleReader[T Uint] struct {
	HasAlpha bool
	Bits     uint
}

func (*GrayscaleReader[T]) ReadPixels 

func (self *GrayscaleReader[T]) ReadPixels(reader *bytes.Reader, n uint32) ([]Pixel, error)

type Histogram 

type Histogram map[uint16]uint64

type IByteBuffer 

type IByteBuffer interface {
	GetRawData() []byte
	GetReader() *bytes.Reader
}

Abstract chunk data to handle big chunks in the future

type IDatMemoryReader 

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

func (*IDatMemoryReader) Reader 

func (idat *IDatMemoryReader) Reader() io.Reader

type IHDRChunk 

type IHDRChunk struct {
	Width       uint32
	Height      uint32
	Bitdepth    byte
	Colortype   byte
	Compression byte
	Filter      byte
	Interlace   byte
}

func (*IHDRChunk) FilterStep 

func (ihdr *IHDRChunk) FilterStep() uint32

func (*IHDRChunk) GetBytesPerLine 

func (self *IHDRChunk) GetBytesPerLine() (uint32, error)

func (*IHDRChunk) GetSamples 

func (self *IHDRChunk) GetSamples() (uint32, error)

func (*IHDRChunk) HasAlpha 

func (self *IHDRChunk) HasAlpha() bool

type IdentityFilter 

type IdentityFilter struct{}

func (*IdentityFilter) Process 

func (f *IdentityFilter) Process(data []byte, processed [][]byte) ([]byte, error)

type ImageBuilder 

type ImageBuilder interface {
	BuildPixels([][]byte) (*ImageData, error)
}

type ImageData 

type ImageData struct {
	Metadata *IHDRChunk
	Pixels   [][]Pixel
}

func ReadPng 

func ReadPng(filename string) (*ImageData, error)

func (*ImageData) Mean 

func (self *ImageData) Mean() []uint64

type MemoryBuffer 

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

func (*MemoryBuffer) GetRawData 

func (memoryData *MemoryBuffer) GetRawData() []byte

func (*MemoryBuffer) GetReader 

func (self *MemoryBuffer) GetReader() *bytes.Reader

type Palette 

type Palette struct{}

type PaletteImageBuilder 

type PaletteImageBuilder struct {
	IHDR *IHDRChunk
	PLTE *Palette
}

func (*PaletteImageBuilder) BuildPixels 

func (self *PaletteImageBuilder) BuildPixels(data [][]byte) (*ImageData, error)

type Pixel 

type Pixel interface {
	Uint16() []uint16
}

type PixelReader 

type PixelReader[T Uint] interface {
	ReadPixels(reader *bytes.Buffer, n uint32) ([]Pixel, error)
}

type PixelValue 

type PixelValue []uint32

type RGBImageBuilder 

type RGBImageBuilder[T Uint] struct {
	IHDR *IHDRChunk
}

func (*RGBImageBuilder[T]) BuildPixels 

func (self *RGBImageBuilder[T]) BuildPixels(data [][]byte) (*ImageData, error)

type RGBPixel 

type RGBPixel[T Uint] struct {
	// contains filtered or unexported fields
}

func CreateRGB 

func CreateRGB[T Uint](r T, g T, b T) *RGBPixel[T]

func CreateRGBA 

func CreateRGBA[T Uint](r T, g T, b T, a T) *RGBPixel[T]

func (*RGBPixel[T]) Uint16 

func (self *RGBPixel[T]) Uint16() []uint16

type RgbReader 

type RgbReader[T Uint] struct {
	HasAlpha bool
	Bits     uint
}

func (*RgbReader[T]) ReadPixels 

func (self *RgbReader[T]) ReadPixels(reader *bytes.Reader, n uint32) ([]Pixel, error)

type Uint 

type Uint interface {
	uint | uint8 | uint16 | uint32 | uint64
}

type UndoAverageFilter 

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

func (*UndoAverageFilter) Process 

func (self *UndoAverageFilter) Process(data []byte, processed [][]byte) ([]byte, error)

type UndoPaethFilter 

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

func (*UndoPaethFilter) PaethPredictor 

func (self *UndoPaethFilter) PaethPredictor(a byte, b byte, c byte) byte

func (*UndoPaethFilter) Process 

func (self *UndoPaethFilter) Process(data []byte, processed [][]byte) ([]byte, error)

type UndoSubFilter 

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

func (*UndoSubFilter) Process 

func (f *UndoSubFilter) Process(data []byte, processed [][]byte) ([]byte, error)

type UndoUpFilter 

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

func (*UndoUpFilter) Process 

func (self *UndoUpFilter) Process(data []byte, processed [][]byte) ([]byte, error)

Source Files

View all Source files

Jump to

Keyboard shortcuts

? : This menu
/ : Search site
f or F : Jump to
y or Y : Canonical URL
go.dev uses cookies from Google to deliver and enhance the quality of its services and to analyze traffic. Learn more.