Tuesday, September 9, 2008

JPEG Marker codes

I'm doing a bit of JPEG manipulation for a project and it took me longer than I would have liked to find a consise table of JPEG segment markers or frame markers or whatever you want to call them. Here's a C# enum with all the values. Hopefully that will save some typing for you.

        public enum JpegMarkers
            // Start of Frame markers, non-differential, Huffman coding
            HuffBaselineDCT = 0xFFC0,
            HuffExtSequentialDCT = 0xFFC1,
            HuffProgressiveDCT = 0xFFC2,
            HuffLosslessSeq = 0xFFC3,

            // Start of Frame markers, differential, Huffman coding
            HuffDiffSequentialDCT = 0xFFC5,
            HuffDiffProgressiveDCT = 0xFFC6,
            HuffDiffLosslessSeq = 0xFFC7,

            // Start of Frame markers, non-differential, arithmetic coding
            ArthBaselineDCT = 0xFFC8,
            ArthExtSequentialDCT = 0xFFC9,
            ArthProgressiveDCT = 0xFFCA,
            ArthLosslessSeq = 0xFFCB,

            // Start of Frame markers, differential, arithmetic coding
            ArthDiffSequentialDCT = 0xFFCD,
            ArthDiffProgressiveDCT = 0xFFCE,
            ArthDiffLosslessSeq = 0xFFCF,

            // Huffman table spec
            HuffmanTableDef = 0xFFC4,

            // Arithmetic table spec
            ArithmeticTableDef = 0xFFCC,

            // Restart Interval termination
            RestartIntervalStart = 0xFFD0,
            RestartIntervalEnd = 0xFFD7,

            // Other markers
            StartOfImage = 0xFFD8,
            EndOfImage = 0xFFD9,
            StartOfScan = 0xFFDA,
            QuantTableDef = 0xFFDB,
            NumberOfLinesDef = 0xFFDC,
            RestartIntervalDef = 0xFFDD,
            HierarchProgressionDef = 0xFFDE,
            ExpandRefComponents = 0xFFDF,

            // App segments
            App0 = 0xFFE0,
            App1 = 0xFFE1,
            App2 = 0xFFE2,
            App3 = 0xFFE3,
            App4 = 0xFFE4,
            App5 = 0xFFE5,
            App6 = 0xFFE6,
            App7 = 0xFFE7,
            App8 = 0xFFE8,
            App9 = 0xFFE9,
            App10 = 0xFFEA,
            App11 = 0xFFEB,
            App12 = 0xFFEC,
            App13 = 0xFFED,
            App14 = 0xFFEE,
            App15 = 0xFFEF,

            // Jpeg Extensions
            JpegExt0 = 0xFFF0,
            JpegExt1 = 0xFFF1,
            JpegExt2 = 0xFFF2,
            JpegExt3 = 0xFFF3,
            JpegExt4 = 0xFFF4,
            JpegExt5 = 0xFFF5,
            JpegExt6 = 0xFFF6,
            JpegExt7 = 0xFFF7,
            JpegExt8 = 0xFFF8,
            JpegExt9 = 0xFFF9,
            JpegExtA = 0xFFFA,
            JpegExtB = 0xFFFB,
            JpegExtC = 0xFFFC,
            JpegExtD = 0xFFFD,

            // Comments
            Comment = 0xFFFE,

            // Reserved
            ArithTemp = 0xFF01,
            ReservedStart = 0xFF02,
            ReservedEnd = 0xFFBF

1 comment:

Alex said...

Recently, I've been trying to find information about the JPEG image format, and the different headers stored in it. I am attempting to make a library for reading and modifying JPEG headers. (and eventually, I will add the functionality into it to read JPEG image data, uncompress it, and feed it as RGB for user editing, then convert it back and compress it)

Anyway, this post is very helpful, because it is quite difficult to find useful information about the markers and such stored in a JPEG header. So far, what I have been able to get is the format for (stored in APP0) JFIF/JFXX, (stored in APP1) EXIF, and (used by EXIF) TIFF. But I'm still a long ways away from the whole JPEG format, and the TIFF reference has a lot in it, the official TIFF documentation is 115 pages.

Anyway, thank you for this reference, it's very helpful!