You can use easy converting utility called Total GIS Converter to transform LizardTech MrSID image file (.sid) to the JPEG bitmap image picture format (.jpeg). This will of course just create common image and all the special metada that might have been part of .sid file will be lost.
Convert LizardTech MrSID image file format to JPEG bitmap image format.
We have found 2 software records in our database eligible for .sid to .jpeg file format conversion.
Microsoft Windows software - convert sid to jpeg on Windows
A dedicated converter for SID format
Convert from sid file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned sid to jpeg. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
A converter that is able to transform various GIS file formats