VisibleGif - Processes

This page describes the processes involved in using VisibleGif.

1. GIF to XML Conversion

In this process an existing GIF image file is used as input to VisibleGif. Processing parameters are supplied to VisibleGiF. VisibleGif creates as output file an equivalent text editable file in XML format.

2. XML Optimisation

The XML format file can be analysed to see if the GIF image "internals" are consistent with that required. The number of colours and the use of colours (anti-aliasing) are elements to be reviewed.

The XML format file can be edited to produce the XML for an operationally efficient image. For example "text" and "comment" tag blocks can be removed. The colour tables and "LZW minimum size" can be reduced to the minimum. Copyright information can be added. Alternatively copyright information can be removed.

Example of the process used to remove comments

1. An XML file equivalent to the GIF image file is produced.
2. The XML file is opened in a text editor program.
3. A search is made for the text string "<comment>". If this string is not found the GIF image does not contain a comments block. No further action is required.
4. All the text from the "<comment>" tag to the "</comment>" tag is deleted.
5. The "<comment>" tag and the "</comment>" tag are deleted.
6. The amended XML file is saved.
7. The amended GIF image file is produced using the amended XML file as input.

3. XML to GIF Generation

In this process an XML file which is the equivalent of the desired GIF image file size is used as input to VisibleGif. VisibleGif creates as output file the desired GIF image.