Class GIFFile

Represents the binary view of a GIF file.

Inheritance

System.Object

ImageFile

GIFFile

Inherited Members

ImageFile.Format

ImageFile.Properties

ImageFile.Thumbnail

ImageFile.Item[Int32]

ImageFile.Encoding

ImageFile.Errors

ImageFile.Save(String)

ImageFile.Save(Stream)

ImageFile.SaveAsync(String)

ImageFile.SaveAsync(Stream)

ImageFile.FromFile(String)

ImageFile.FromFile(String, Encoding)

ImageFile.FromStream(Stream)

ImageFile.FromStream(Stream, Encoding)

ImageFile.FromBuffer(Byte[])

ImageFile.FromBuffer(Byte[], Encoding)

ImageFile.FromFileAsync(String)

ImageFile.FromFileAsync(String, Encoding)

ImageFile.FromStreamAsync(Stream)

ImageFile.FromStreamAsync(Stream, Encoding)

ImageFile.FromStreamInternal(MemoryStream, Encoding)

Namespace: ExifLibrary

Assembly: ExifLibrary.dll

Syntax

public class GIFFile : ImageFile

Constructors

GIFFile(MemoryStream, Encoding)

Initializes a new instance of the GIFFile class from the specified data stream.

Declaration

protected GIFFile(MemoryStream stream, Encoding encoding)

Parameters

Type	Name	Description
System.IO.MemoryStream	stream	A stream that contains image data.
System.Text.Encoding	encoding	The encoding to be used for text metadata when the source encoding is unknown.

Properties

BackcolorIndex

Gets the index of the backcolor in the global color table.

Declaration

public byte BackcolorIndex { get; }

Property Value

Type	Description
System.Byte

Blocks

Gets the blocks contained in the GIFFile.

Declaration

public List<GIFBlock> Blocks { get; }

Property Value

Type	Description
System.Collections.Generic.List<GIFBlock>

ColorResolution

Gets the bumber of bits per primary color available.

Declaration

public byte ColorResolution { get; }

Property Value

Type	Description
System.Byte

GCT

Gets the global color table.

Declaration

public byte[, ] GCT { get; }

Property Value

Type	Description
System.Byte[,]

HasGCT

Gets whether the file contains a global color table.

Declaration

public bool HasGCT { get; }

Property Value

Type	Description
System.Boolean

IsGCTSorted

Gets whether the global color table is sorted.

Declaration

public bool IsGCTSorted { get; }

Property Value

Type	Description
System.Boolean

PixelAspectRatio

Gets the pixel aspect ratio. The actual aspect ratio is calculated as: Aspect Ratio = (Pixel Aspect Ratio + 15) / 64.

Declaration

public byte PixelAspectRatio { get; }

Property Value

Type	Description
System.Byte

ScreenHeight

Gets the raster height in pixels.

Declaration

public ushort ScreenHeight { get; }

Property Value

Type	Description
System.UInt16

ScreenWidth

Gets the raster width in pixels.

Declaration

public ushort ScreenWidth { get; }

Property Value

Type	Description
System.UInt16

SizeOfGCT

Gets the size of the global color table.

Declaration

public byte SizeOfGCT { get; }

Property Value

Type	Description
System.Byte

Version

Gets the GIF version string. e.g. 89a

Declaration

public string Version { get; }

Property Value

Type	Description
System.String

Methods

Crush()

Decreases file size by removing all ancillary chunks.

Declaration

public override void Crush()

Overrides

ImageFile.Crush()

ReadColorTable(MemoryStream, Int32)

Reads a GIF color table.

Declaration

protected byte[, ] ReadColorTable(MemoryStream stream, int length)

Parameters

Type	Name	Description
System.IO.MemoryStream	stream	A stream that contains image data.
System.Int32	length	Length of color table.

Returns

Type	Description
System.Byte[,]

ReadDataBlock(MemoryStream)

Reads data sub-blocks.

Declaration

protected byte[][] ReadDataBlock(MemoryStream stream)

Parameters

Type	Name	Description
System.IO.MemoryStream	stream	A stream that contains image data.

Returns

Type	Description
System.Byte[][]

ReadMetadata()

Reads GIF metadata in extension blocks.

Declaration

protected void ReadMetadata()

SaveInternal(MemoryStream)

Saves the ImageFile to the given stream.

Declaration

protected override void SaveInternal(MemoryStream stream)

Parameters

Type	Name	Description
System.IO.MemoryStream	stream	The data stream used to save the image.

Overrides

ImageFile.SaveInternal(MemoryStream)

WriteColorTable(MemoryStream, Byte[,])

Writes GIF color table.

Declaration

protected void WriteColorTable(MemoryStream stream, byte[, ] table)

Parameters

Type	Name	Description
System.IO.MemoryStream	stream	A stream that contains image data.
System.Byte[,]	table	Color table.

WriteDataBlock(MemoryStream, Byte[][])

Writes data sub-blocks.

Declaration

protected void WriteDataBlock(MemoryStream stream, byte[][] data)

Parameters

Type	Name	Description
System.IO.MemoryStream	stream	A stream that contains image data.
System.Byte[][]	data	A data sub-block

WriteMetadata()

Writes GIF metadata into extension blocks.

Declaration

protected void WriteMetadata()