Re: [Lcms-user] Pentax JPG and TIF Files
Thank you, those were exactly the answers I needed, and way more thorough than I could've hoped for. -- Frank Gore Project Manager www.projectpontiac.com On Sun, Jan 17, 2010 at 5:03 PM, Larry Reeve wrote: > LCMS does not have anything to do with the color space defined in the EXIF > block of a JPEG file. There is no embedded profile. It is up to the > application using LCMS to evaluate the color space definitions in the EXIF > and take the action to load and use an Adobe RGB profile if it is needed. > The DCF Optional Color Space (see paragraph 6.2 of of JEITA CP-3461 "Design > rule for Camera File system DCF Version 2.0") defines the values that should > alert an application to take this action: > > Color Space: Uncalibrated > WhitePoint X: 0.31 > WhitePoint Y: 0.33 > Chromaticity Red(X): 0.64 > Chromaticity Red(Y): 0.33 > Chromaticity Green(X): 0.21 > Chromaticity Green(Y): 0.71 > Chromaticity Blue(X): 0.15 > Chromaticity Blue(Y): 0.06 > YCbCrCoefficient 1: 0.30 > YCbCrCoefficient 2: 0.59 > YCbCrCoefficient 3: 0.11 > > Larry Reeve > >> -Original Message- >> From: Frank Gore [mailto:g...@projectpontiac.com] >> Sent: Sunday, January 17, 2010 3:40 PM >> To: lcms-user@lists.sourceforge.net >> Subject: Re: [Lcms-user] Pentax JPG and TIF Files >> >> On Sun, Jan 17, 2010 at 4:18 AM, Louis Solomon >> wrote: >> > have you tried removing the whole exif chunk from the jpg? >> >> I guess that depends on whether I did it right. I used: >> mogrify -strip filename.jpg >> Does that remove just the EXIF metadata, or other stuff too? In any >> case, doing this did cause Photoshop to no longer recognize a color >> profile for this image. So I guess the color profile is only listed as >> part of the EXIF data after all and not embedded in the file (just >> like someone else mentioned already). >> >> On Sun, Jan 17, 2010 at 7:32 AM, Larry Reeve >> wrote: >> > A DCF aware application sees this information and processes the image >> > accordingly (which means use an Adobe RGB profile). >> >> So does that mean the fault lies with the applications that use lcms, >> or with lcms itself? I'm not familiar with how lcms is used by >> applications. My understanding was that Gimp used lcms for color >> profile detection as well as color handling and conversion. Which part >> of the process needs to be DCF aware? >> >> -- >> Frank Gore >> Project Manager >> www.projectpontiac.com >> >> --- >> --- >> Throughout its 18-year history, RSA Conference consistently attracts >> the >> world's best and brightest in the field, creating opportunities for >> Conference >> attendees to learn about information security's most important issues >> through >> interactions with peers, luminaries and emerging and established >> companies. >> http://p.sf.net/sfu/rsaconf-dev2dev >> ___ >> Lcms-user mailing list >> Lcms-user@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/lcms-user > > -- Throughout its 18-year history, RSA Conference consistently attracts the world's best and brightest in the field, creating opportunities for Conference attendees to learn about information security's most important issues through interactions with peers, luminaries and emerging and established companies. http://p.sf.net/sfu/rsaconf-dev2dev ___ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
Re: [Lcms-user] Pentax JPG and TIF Files
On Sun, Jan 17, 2010 at 4:18 AM, Louis Solomon wrote: > have you tried removing the whole exif chunk from the jpg? I guess that depends on whether I did it right. I used: mogrify -strip filename.jpg Does that remove just the EXIF metadata, or other stuff too? In any case, doing this did cause Photoshop to no longer recognize a color profile for this image. So I guess the color profile is only listed as part of the EXIF data after all and not embedded in the file (just like someone else mentioned already). On Sun, Jan 17, 2010 at 7:32 AM, Larry Reeve wrote: > A DCF aware application sees this information and processes the image > accordingly (which means use an Adobe RGB profile). So does that mean the fault lies with the applications that use lcms, or with lcms itself? I'm not familiar with how lcms is used by applications. My understanding was that Gimp used lcms for color profile detection as well as color handling and conversion. Which part of the process needs to be DCF aware? -- Frank Gore Project Manager www.projectpontiac.com -- Throughout its 18-year history, RSA Conference consistently attracts the world's best and brightest in the field, creating opportunities for Conference attendees to learn about information security's most important issues through interactions with peers, luminaries and emerging and established companies. http://p.sf.net/sfu/rsaconf-dev2dev ___ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
Re: [Lcms-user] Pentax JPG and TIF Files
This is quite normal. No dslr I know embeds a profil into the jpgs nor into the raws. It is allways just a flag in the exif-data. For Adobe RBG the filename starts with an underscore as a second hint. It is up to the application to interpret these flags. Blame the gimp people for this ;-) By the way: The Exif-flag method is quite stupid and not save. You can easely create a jpg with a confusing setup: - exif-flag says sRGB - name begins withs underscore - eci-RGB profil is embedded I did not test whether the display of my K10D or K-7 can handle AdobeRGB correct. Maybe they just show the tiny preview/tumbnail that is normally not color managed. Winfried Frank Gore schrieb: > Hello, > > After much research and many subscriptions to mailing lists, slowly > working my way up the food chain, I find myself here in the hopes that > I can find an answer. > > I own a Pentax K-7 DSLR. It seems that any application that uses > LittleCMS for color management does not detect the embedded color > profile in the JPG and TIF files generated by my camera. This caused a > bit of a stir on pentaxforums.com, and I've determined that > camera-generated JPG and TIF files from many (perhaps all?) Pentax > DSLR models embed the color profile in a way that LittleCMS does not > detect. This is not limited to just my K-7. Pentax includes an option > to generate these files in either sRGB or Adobe RGB color space, but > neither one gets detected. Even the built-in monitor of the camera > fails to show the Adobe RGB images properly during playback. It > interprets them as sRGB, which makes them look washed out and bland > (does Pentax use LittleCMS in the camera firmware?). Due to the > inconsistent way that some applications handle this situation, it's > caused some headaches to my fellow Pentaxians. For example, Gimp does > not ask what to do when no color profile is detected, it just > interprets it in whatever working space is currently set in the > preferences. > > Whatever system Adobe uses does properly detect the embedded color profile. > > So far, my research has led me to believe this is due to an ICC > profile that's either embedded in a non-standard way, or in a version > that LittleCMS does not yet support. > > I wonder if anyone could shed some light on the subject, and if > there's anything I can do to help solve this problem. I am not a > developer, I'm just an amateur photographer who used to do a lot of > graphic design, but I'd be happy to help in any way I can. My system > (openSUSE 11.2) currently has lcms-1.18a installed. > > Here are two files straight from my camera for reference: > > Adobe RGB: > http://lh6.ggpht.com/_HAZjMzZWrtc/S05qkb7KkYI/BCw/oPJ80XXYH-Y/d/_GOR3359.JPG > > sRGB: > http://lh3.ggpht.com/_HAZjMzZWrtc/S05qk1yxBOI/BC0/5kXGfiIIF7s/d/GORE3360.JPG > > Thanks, -- Throughout its 18-year history, RSA Conference consistently attracts the world's best and brightest in the field, creating opportunities for Conference attendees to learn about information security's most important issues through interactions with peers, luminaries and emerging and established companies. http://p.sf.net/sfu/rsaconf-dev2dev ___ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
Re: [Lcms-user] Pentax JPG and TIF Files
A quick look lead me to believe that these jpgs do not have ICC profiles embedded in them. ICC profiles are normally stored in a jpeg 'chunk' ( APP2(0xffe2) + "ICC_PROFILE" ) using http://www.sno.phy.queensu.ca/~phil/exiftool/ I see the following in the two files Color Space : Uncalibrated Interoperability Index : R03 - DCF option file (Adobe RGB) Color Space : sRGB Interoperability Index : R98 - DCF basic file (sRGB) So I guess you need a fully EXIF compliant program to make use of this info. Most progs _I_ use (and write) ignore exif, but do read embedded icc. Therefore IMHO Pentax is silly :) Louis Solomon www.SteelBytes.com -Original Message- From: Frank Gore [mailto:g...@projectpontiac.com] Sent: Sunday, 17 January 2010 4:21 PM To: lcms-user@lists.sourceforge.net Subject: [Lcms-user] Pentax JPG and TIF Files Hello, After much research and many subscriptions to mailing lists, slowly working my way up the food chain, I find myself here in the hopes that I can find an answer. I own a Pentax K-7 DSLR. It seems that any application that uses LittleCMS for color management does not detect the embedded color profile in the JPG and TIF files generated by my camera. This caused a bit of a stir on pentaxforums.com, and I've determined that camera-generated JPG and TIF files from many (perhaps all?) Pentax DSLR models embed the color profile in a way that LittleCMS does not detect. This is not limited to just my K-7. Pentax includes an option to generate these files in either sRGB or Adobe RGB color space, but neither one gets detected. Even the built-in monitor of the camera fails to show the Adobe RGB images properly during playback. It interprets them as sRGB, which makes them look washed out and bland (does Pentax use LittleCMS in the camera firmware?). Due to the inconsistent way that some applications handle this situation, it's caused some headaches to my fellow Pentaxians. For example, Gimp does not ask what to do when no color profile is detected, it just interprets it in whatever working space is currently set in the preferences. Whatever system Adobe uses does properly detect the embedded color profile. So far, my research has led me to believe this is due to an ICC profile that's either embedded in a non-standard way, or in a version that LittleCMS does not yet support. I wonder if anyone could shed some light on the subject, and if there's anything I can do to help solve this problem. I am not a developer, I'm just an amateur photographer who used to do a lot of graphic design, but I'd be happy to help in any way I can. My system (openSUSE 11.2) currently has lcms-1.18a installed. Here are two files straight from my camera for reference: Adobe RGB: http://lh6.ggpht.com/_HAZjMzZWrtc/S05qkb7KkYI/BCw/oPJ80XXYH-Y/d/ _GOR3359.JPG sRGB: http://lh3.ggpht.com/_HAZjMzZWrtc/S05qk1yxBOI/BC0/5kXGfiIIF7s/d/ GORE3360.JPG Thanks, -- Frank Gore Project Manager www.projectpontiac.com -- Throughout its 18-year history, RSA Conference consistently attracts the world's best and brightest in the field, creating opportunities for Conference attendees to learn about information security's most important issues through interactions with peers, luminaries and emerging and established companies. http://p.sf.net/sfu/rsaconf-dev2dev ___ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user -- Throughout its 18-year history, RSA Conference consistently attracts the world's best and brightest in the field, creating opportunities for Conference attendees to learn about information security's most important issues through interactions with peers, luminaries and emerging and established companies. http://p.sf.net/sfu/rsaconf-dev2dev ___ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
