JPEG Tags

This table lists information extracted by ExifTool from JPEG images.

Tag IDTag Name WritableValues / Notes
'APP0' JFIF
JFXX
CIFF
-
-
-
--> JFIF Tags
--> JFIF Extension Tags
--> CanonRaw Tags
'APP1' EXIF
XMP
-
-
--> EXIF Tags
--> XMP Tags
'APP2' ICC_Profile
FPXR
-
-
--> ICC_Profile Tags
--> FlashPix Tags
'APP3' Meta - --> Kodak Meta Tags
'APP5' RMETA - --> Ricoh RMETA Tags
'APP6' EPPIM - --> JPEG EPPIM Tags
'APP8' SPIFF - --> JPEG SPIFF Tags
'APP10' Comment N (PhotoStudio Unicode comment)
'APP12' PictureInfo
Ducky
-
-
--> APP12 PictureInfo Tags
--> APP12 Ducky Tags
'APP13' Photoshop
Adobe_CM
-
-
--> Photoshop Tags
--> JPEG AdobeCM Tags
'APP14' Adobe - --> JPEG Adobe Tags
'APP15' GraphicConverter - --> JPEG GraphConv Tags
'COM' Comment Y  
'SOF' StartOfFrame - --> JPEG SOF Tags
'Trailer' AFCP
CanonVRD
FotoStation
PhotoMechanic
MIE
PreviewImage
-
-
-
-
-
Y
--> AFCP Tags
--> CanonVRD Tags
--> FotoStation Tags
--> PhotoMechanic Tags
--> MIE Tags

JPEG EPPIM Tags

APP6 is used in by the Toshiba PDR-M700 to store a TIFF structure containing PrintIM information.

Tag IDTag Name WritableValues / Notes
0xc4a5 PrintIM undef --> PrintIM Tags

JPEG SPIFF 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).

IndexTag Name WritableValues / 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  

JPEG AdobeCM Tags

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.

IndexTag Name WritableValues / Notes
0 AdobeCMType N  

JPEG Adobe Tags

The "Adobe" APP14 segment stores image encoding information for DCT filters.

IndexTag Name WritableValues / 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

JPEG GraphConv Tags

APP15 is used by GraphicConverter to store JPEG quality.

Tag IDTag Name WritableValues / Notes
'Q' Quality N  

JPEG SOF Tags

This information is extracted from the JPEG Start Of Frame segment.

Tag Name WritableValues / 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 5, 2007

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