diff options
-rw-r--r-- | Canon_CR2.mdwn | 50 | ||||
-rw-r--r-- | Canon_CR2.moin | 39 |
2 files changed, 50 insertions, 39 deletions
diff --git a/Canon_CR2.mdwn b/Canon_CR2.mdwn new file mode 100644 index 0000000..47e6747 --- /dev/null +++ b/Canon_CR2.mdwn @@ -0,0 +1,50 @@ + +CR2 files are generated by Canon cameras, starting the 20D, 350D/Digital Rebel Xt and 1D. They supersede the older [[Canon CRW|CRW]]. + + +# MIME type + +image/x-canon-cr2 +# Organisation + +Canon CR2 files are TIFF files. All is organised in a TIFF / IFD file. + +On of the differenciation with the CR2 files is that they have a header before the IFD0. This does not violate the TIFF spec. +[[!table header="no" class="mointable" data=""" + **offset** | **length** | **description** + 0 | 8 | TIFF header + 8 | 2 | litteral 'CR' + 10 | 1 | major version (2) + 11 | 1 | minor version (0) + 12 | 4 | (long) for the offset of the IFD3 that contain the RAW data. (in the TIFF byte order) +"""]] + +Exif is attached to the ExifIFD of IFD0. The CFA data is in IFD3. + + +# Compression + +Canon CR2 files use the old original [[Lossless_JPEG|Lossless_JPEG]] standard for the RAW data. The same used by [[Adobe DNG|Adobe DNG]]. + +Source: [[http://www.adobeforums.com/cgi-bin/webx/.3bc36454/0|http://www.adobeforums.com/cgi-bin/webx/.3bc36454/0]] (Dead link) + +The width dimension specified in the JPEG stream is actually half the reality because it takes into account 2 channels per sample (the dimension of the CFA pattern). + +350D, 5D and 30D files have a different layout. IFD3 (where the CFA is located) has the tag 0xc640 that contains 3 SHORT. 1, x, y. x is the number of column of the first "slice" of the image, y is for the second "slice".** I don't know what the 1 mean.** + +The slicing means that the output scanlines have to be reorganised as they are shorter to have a top -> bottom then left -> right, a bit like columns of text. (TODO: do a nice diagram) + + +# Modified files + +Apparently Canon's proprietary software modifies the RAW file. Other proprietary software seems to choke on said modified files ([[http://www.prophotohome.com/forum/raw-photo-processing-software-technique/62864-cr2-raws-converted-dpp-wont-open-aperture.html|http://www.prophotohome.com/forum/raw-photo-processing-software-technique/62864-cr2-raws-converted-dpp-wont-open-aperture.html]]). + +[[ExifTool|ExifTool]] has some info: + +* [[http://www.cpanforum.com/threads/1055|http://www.cpanforum.com/threads/1055]] +* [[http://www.cpanforum.com/threads/5170|http://www.cpanforum.com/threads/5170]] + +# References + +* [[http://lclevy.free.fr/cr2/|http://lclevy.free.fr/cr2/]] +* [[http://web.archive.org/web/20061125031802/http://crousseau.free.fr/imgfmt_raw.htm|http://web.archive.org/web/20061125031802/http://crousseau.free.fr/imgfmt_raw.htm]] (in French, by one of the developers of DxO)
\ No newline at end of file diff --git a/Canon_CR2.moin b/Canon_CR2.moin deleted file mode 100644 index 12527f4..0000000 --- a/Canon_CR2.moin +++ /dev/null @@ -1,39 +0,0 @@ -CR2 files are generated by Canon cameras, starting the 20D, 350D/Digital Rebel Xt and 1D. They supersede the older [[CRW|Canon CRW]].
-
-= MIME type =
-image/x-canon-cr2
-= Organisation =
-Canon CR2 files are TIFF files. All is organised in a TIFF / IFD file.
-
-On of the differenciation with the CR2 files is that they have a header before the IFD0. This does not violate the TIFF spec.
-
-|| '''offset''' || '''length''' || '''description''' ||
-|| 0 || 8 || TIFF header ||
-|| 8 || 2 || litteral 'CR' ||
-|| 10 || 1 || major version (2) ||
-|| 11 || 1 || minor version (0) ||
-|| 12 || 4 || (long) for the offset of the IFD3 that contain the RAW data. (in the TIFF byte order) ||
-
-Exif is attached to the ExifIFD of IFD0. The CFA data is in IFD3.
-
-= Compression =
-Canon CR2 files use the old original [[Lossless_JPEG]] standard for the RAW data. The same used by [[Adobe DNG]].
-
-Source: http://www.adobeforums.com/cgi-bin/webx/.3bc36454/0 (Dead link)
-
-The width dimension specified in the JPEG stream is actually half the reality because it takes into account 2 channels per sample (the dimension of the CFA pattern).
-
-350D, 5D and 30D files have a different layout. IFD3 (where the CFA is located) has the tag 0xc640 that contains 3 SHORT. 1, x, y. x is the number of column of the first "slice" of the image, y is for the second "slice".''' I don't know what the 1 mean.'''
-
-The slicing means that the output scanlines have to be reorganised as they are shorter to have a top -> bottom then left -> right, a bit like columns of text. (TODO: do a nice diagram)
-
-= Modified files =
-Apparently Canon's proprietary software modifies the RAW file. Other proprietary software seems to choke on said modified files (http://www.prophotohome.com/forum/raw-photo-processing-software-technique/62864-cr2-raws-converted-dpp-wont-open-aperture.html).
-
-ExifTool has some info:
- * http://www.cpanforum.com/threads/1055
- * http://www.cpanforum.com/threads/5170
-
-= References =
- * http://lclevy.free.fr/cr2/
- * http://web.archive.org/web/20061125031802/http://crousseau.free.fr/imgfmt_raw.htm (in French, by one of the developers of DxO)
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