[Digikam-devel] [Bug 223232] Digikam Does Not Detect the Color Profile in DCF Files

[Frank Gore]

https://bugs.kde.org/show_bug.cgi?id=223232





--- Comment #2 from Frank Gore <gore projectpontiac com>  2010-01-18 15:26:10 ---
I'm using libexiv2 0.18.2.

This is a quote from a developer on the LittleCMS mailing list (where I brought
up this issue before filing a bug here):

On Sun, Jan 17, 2010 at 7:32 AM, Larry Reeve <larry at polybytes.com> wrote:
> The first image is in "DCF Colorspace". This can be seen from the following
> entries in the EXIF:
>
> 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
>
> A DCF aware application sees this information and processes the image
> accordingly (which means use an Adobe RGB profile).

And a further reply when I asked if this was an application-level or
library-level issue:

On Sun, Jan 17, 2010 at 5:03 PM, Larry Reeve <larry at polybytes.com> 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

Here are two files straight from my camera as examples. One is in sRGB
colorspace, the other is in Adobe RGB colorspace. Both conform to the DCF 2.0
specification. Both have their color space detected properly in commercial
applications.

sRGB:
http://lh3.ggpht.com/_HAZjMzZWrtc/S05qk1yxBOI/AAAAAAAABC0/5kXGfiIIF7s/d/GORE3360.JPG

Adobe RGB:
http://lh6.ggpht.com/_HAZjMzZWrtc/S05qkb7KkYI/AAAAAAAABCw/oPJ80XXYH-Y/d/_GOR3359.JPG

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