Casio V-N500 - Manual (Page 234)

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The upcoming JPEG Part 3 standard defines a file format called SPIFF. SPIFF is
interoperable with JFIF, in the sense that most JFIF decoders should be able to read the
most common variant of SPIFF. SPIFF has some technical advantages over JFIF, but its
major claim to fame is simply that it is an offi cial standard rather than an informal one. At
this point it is unclear whether SPIFF will supersede JFIF or whether JFIF will remain the
de-facto standard. IJG intends to support SPIFF once the standard is frozen, but we have
not decided whether it should become our default output format or not. (In any case, our
decoder will remain capable of reading JFIF indefi nitely.)
Various proprietary fi le formats incorporating JPEG compression also exist. We have little
or no sympathy for the existence of these formats. Indeed, one of the original reasons for
developing this free software was to help force convergence on common, open format
standards for JPEG fi les. Don’t use a proprietary fi le format!
TO DO
======
The major thrust for v7 will probably be improvement of visual quality. The current
method for scaling the quantization tables is known not to be very good at low Q
values. We also intend to investigate block boundary smoothing, “poor man’s variable
quantization”, and other means of improving quality-vs-file-size performance without
sacrifi cing compatibility.
In future versions, we are considering supporting some of the upcoming JPEG Part 3
extensions --- principally, variable quantization and the SPIFF fi le format.
As always, speeding things up is of great interest.
Please send bug reports, offers of help, etc. to [email protected].