You can select one of several compression methods for the photograph. Compression saves disk space but at the expense of compression and decompression time. There are 3 possible selections in this pull-down menu:
1. Uncompressed - the photograph is stored as a PCX and will occupy approximately 130Kb per picture
2. RLE Compression - reduces the file size about 30% over uncompressed, but at the expense of some decompression time. This takes no less time to compress or decompress than JPEG and does a poorer job and is therefore not recommended for new databases. It is provided for backward compatibility with older databases which may have selected photo compression
3. JPEG Compression - an industry-standard compression scheme which results in files 15-20Kb in size. The compression and decompression times are reasonable and the quality of the picture is good
4. PNG Portable Network Graphics – a rapidly developing standard for loss-less image compression, similar to CompuServe's GIF but with better compression and is non-proprietary.
It is best to select PNG compression unless you expect disk storage space to become an issue, and then JPEG is the best choice. Once a database has been created, the compression scheme can be changed, but this can take some time if many photographs exist.