JPEG Tags
This table lists information extracted by ExifTool from JPEG images.
APP6 is used in by the Toshiba PDR-M700 to store a TIFF structure containing
PrintIM information.
| 
| Tag ID | Tag Name | Writable | Values / Notes | 
|---|
 
| 0xc4a5 | PrintIM | undef | --> PrintIM Tags |  | 
This information is found in APP8 of SPIFF-style JPEG images (the "official"
yet rarely used JPEG file format standard: Still Picture Interchange File
Format).
| 
| Index | Tag Name | Writable | Values / Notes | 
|---|
 
| 0 | SPIFFVersion | N |  |  
| 2 | ProfileID | N | 0 = Not Specified 1 = Continuous-tone Base
 2 = Continuous-tone Progressive
 3 = Bi-level Facsimile
 4 = Continuous-tone Facsimile
 |  
| 3 | ColorComponents | N |  |  
| 6 | ImageHeight | N | (at index 4 in specification, but there are 2 extra bytes here in my only
SPIFF sample, version 1.2) |  
| 10 | ImageWidth | N |  |  
| 14 | ColorSpace | N | 0 = Bi-level 1 = YCbCr, ITU-R BT 709, video
 2 = No color space specified
 3 = YCbCr, ITU-R BT 601-1, RGB
 4 = YCbCr, ITU-R BT 601-1, video
 8 = Gray-scale
 9 = PhotoYCC
 10 = RGB
 11 = CMY
 12 = CMYK
 13 = YCCK
 14 = CIELab
 |  
| 15 | BitsPerSample | N |  |  
| 16 | Compression | N | 0 = Uncompressed, interleaved, 8 bits per sample 1 = Modified Huffman
 2 = Modified READ
 3 = Modified Modified READ
 4 = JBIG
 5 = JPEG
 |  
| 17 | ResolutionUnit | N | 0 = None 1 = inches
 2 = cm
 |  
| 18 | YResolution | N |  |  
| 22 | XResolution | N |  |  | 
The "Adobe_CM" APP13 segment presumably contains color management
information, but the meaning of the data is currently unknown.  If anyone
has an idea about what this means, please let me know.
| 
| Index | Tag Name | Writable | Values / Notes | 
|---|
 
| 0 | AdobeCMType | N |  |  | 
The "Adobe" APP14 segment stores image encoding information for DCT filters.
| 
| Index | Tag Name | Writable | Values / Notes | 
|---|
 
| 0 | DCTEncodeVersion | N |  |  
| 1 | APP14Flags0 | N | Bit 15 = Encoded with Blend=1 downsampling |  
| 2 | APP14Flags1 | N |  |  
| 3 | ColorTransform | N | 0 = Unknown (RGB or CMYK) 1 = YCbCr
 2 = YCCK
 |  | 
APP15 is used by GraphicConverter to store JPEG quality.
| 
| Tag ID | Tag Name | Writable | Values / Notes | 
|---|
 
| 'Q' | Quality | N |  |  | 
This information is extracted from the JPEG Start Of Frame segment.
| 
| Tag Name | Writable | Values / Notes | 
|---|
 
| BitsPerSample | N |  |  
| ColorComponents | N |  |  
| EncodingProcess | N | 0x0 = Baseline DCT, Huffman coding 0x1 = Extended sequential DCT, Huffman coding
 0x2 = Progressive DCT, Huffman coding
 0x3 = Lossless, Huffman coding
 0x5 = Sequential DCT, differential Huffman coding
 0x6 = Progressive DCT, differential Huffman coding
 0x7 = Lossless, Differential Huffman coding
 0x9 = Extended sequential DCT, arithmetic coding
 0xa = Progressive DCT, arithmetic coding
 0xb = Lossless, arithmetic coding
 0xd = Sequential DCT, differential arithmetic coding
 0xe = Progressive DCT, differential arithmetic coding
 0xf = Lossless, differential arithmetic coding
 |  
| ImageHeight | N |  |  
| ImageWidth | N |  |  
| YCbCrSubSampling | N | (calculated from components table) '1 1' = YCbCr4:4:4 (1 1)
 '1 2' = YCbCr4:4:0 (1 2)
 '2 1' = YCbCr4:2:2 (2 1)
 '2 2' = YCbCr4:2:0 (2 2)
 '4 1' = YCbCr4:1:1 (4 1)
 '4 2' = YCbCr4:1:0 (4 2)
 |  | 
(This document generated automatically by Image::ExifTool::BuildTagLookup)
Last revised Oct 16, 2007
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