GIF

Description

A bit-mapped graphics file format used by the Web, CompuServe and many bulletin boards. GIF supports color and various resolutions. It also includes data compression, but because it is limited to 256 colors, it is more effective for scanned images such as illustrations than color photos.

Import Library

im8gif.dil

Export Library

im8xgif.del

Remarks

This release supports loading and saving 1, 4, and 8 bit interlaced and non-interlaced GIF files. Multipage Gifs are supported, but generally only used for animated gif. Saving a multipage GIF, with default attribute setting will result in an animated gif that continuously switches between the pages of the file.

By default, for customers outside of the U.S. (until July 2004) GIF support is disabled unless you have a license from Unisys Corporation, which holds a patent on the LZW compression used in GIF files. Unisys Contact Information

Attributes

Name

DataType

Notes

EXTENSION

OPTBLK_STRING

"GIF"

COMMENT

OPTBLK_STRING

Could have an embedded NULL 0

GIF_PLAINTEXT

OPTBLK_STRING

OPTBLK_DELAYED_LOAD

Used for rendering plain text on image, not directly supported

GIF_APPEXT

OPTBLK_BINARY

OPTBLK_DELAYED_LOAD

We will write by default the Netscape extension for animated images on multi page images

GIF_INTERLACE

OPTBLK_BOOL

Indicates how image is loaded

GIF_LOCALCOLOR

OPTBLK_BOOL

Indicates if there is a local color table for a given frame

GIF_GLOBALCOLOR

OPTBLK_BOOL

Indicates if there is a global color table present

GIF_GLOBALCOLORTABLE

OPTBLK_BINARY

OPTBLK_DELAYED_LOAD

Actual global color table data

GIF_SD

OPTBLK_BINARY

Screen Descriptor

GIF_SD_WIDTH

OPTBLK_INT16

Bounding box width for all images

GIF_SD_HEIGHT

OPTBLK_INT16

Bounding box height for all images

GIF_BGCOLOR

OPTBLK_INT32

Background color for all images

GIF_GCE

OPTBLK_BINARY

Graphic Control Extension

GIF_GCE_TRANSIDX

OPTBLK_INT8

Transparency Index for individual frame

GIF_GCE_DELAY

OPTBLK_INT16

Delay in milliseconds for individual frame

GIF_GCE_TRANS

OPTBLK_BOOL

Indicates whether to apply transparency

GIF_GCE_DISPOSAL

OPTBLK_INT8

Disposal method for frame of gif image

GIF_ID

OPTBLK_BINARY

Image Descriptor

GIF_ID_LEFT

OPTBLK_INT16

Frame offset for the left

GIF_ID_TOP

OPTBLK_INT16

Frame offset for the top

GIF_ID_WIDTH

OPTBLK_INT16

Frame width

GIF_ID_HEIGHT

OPTBLK_INT16

Frame height

Name	DataType	Notes
EXTENSION	OPTBLK_STRING	"GIF"
COMMENT	OPTBLK_STRING	Could have an embedded NULL 0
GIF_PLAINTEXT	OPTBLK_STRING	OPTBLK_DELAYED_LOAD

GIF_INTERLACE	OPTBLK_BOOL	Indicates how image is loaded
GIF_LOCALCOLOR	OPTBLK_BOOL	Indicates if there is a local color table for a given frame
GIF_GLOBALCOLOR	OPTBLK_BOOL	Indicates if there is a global color table present
GIF_GLOBALCOLORTABLE	OPTBLK_BINARY	OPTBLK_DELAYED_LOAD

GIF_SD	OPTBLK_BINARY	Screen Descriptor
GIF_SD_WIDTH	OPTBLK_INT16	Bounding box width for all images
GIF_SD_HEIGHT	OPTBLK_INT16	Bounding box height for all images
GIF_BGCOLOR	OPTBLK_INT32	Background color for all images
GIF_GCE	OPTBLK_BINARY	Graphic Control Extension
GIF_GCE_TRANSIDX	OPTBLK_INT8	Transparency Index for individual frame
GIF_GCE_DELAY	OPTBLK_INT16	Delay in milliseconds for individual frame
GIF_GCE_TRANS	OPTBLK_BOOL	Indicates whether to apply transparency
GIF_GCE_DISPOSAL	OPTBLK_INT8	Disposal method for frame of gif image
GIF_ID	OPTBLK_BINARY	Image Descriptor
GIF_ID_LEFT	OPTBLK_INT16	Frame offset for the left
GIF_ID_TOP	OPTBLK_INT16	Frame offset for the top
GIF_ID_WIDTH	OPTBLK_INT16	Frame width
GIF_ID_HEIGHT	OPTBLK_INT16	Frame height