JPEG colorspace confusion

[vmartin]

Let's say I have two JPEG images

Code: Select all

$ identify -verbose one.jpg
Image: one.jpg
  Format: JPEG (Joint Photographic Experts Group JFIF format)
  Class: DirectClass
  Geometry: 3264x2448+0+0
  Resolution: 72x72
  Print size: 45.3333x34
  Units: PixelsPerInch
  Type: TrueColor
  Endianess: Undefined
  Colorspace: RGB
  Depth: 8-bit
...
  Profiles:
    Profile-exif: 31420 bytes
...
  Version: ImageMagick 6.6.9-7 2017-03-14 Q16 http://www.imagemagick.org

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$ identify -verbose two.jpg
Image: two.jpg
  Format: JPEG (Joint Photographic Experts Group JFIF format)
  Class: DirectClass
  Geometry: 320x240+0+0
  Resolution: 72x72
  Print size: 4.44444x3.33333
  Units: PixelsPerInch
  Type: TrueColor
  Endianess: Undefined
  Colorspace: RGB
  Depth: 8-bit
...
  Profiles:
    Profile-8bim: 3602 bytes
    Profile-icc: 3144 bytes
      IEC 61966-2.1 Default RGB colour space - sRGB
...
  Version: ImageMagick 6.6.9-7 2017-03-14 Q16 http://www.imagemagick.org

two.jpg has an explicit sRGB profile, so I assume that the data is sRGB encoded.
What about one.jpg? As I understand it, sRGB is the default so its data should also be sRGB encoded, correct?

What has me confused is that colorspace is listed as RGB in both cases.

MV

[snibgo]

What version of IM are you using? I suspect it is quite old, and a more recent version would show "sRGB".

Yes, images without embedded profiles are usually assumed to be encoded as sRGB.

[vmartin]

Thanks for the quick reply.

I am using the default package version from Ubuntu 12.04:

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  Version: ImageMagick 6.6.9-7 2017-03-14 Q16 http://www.imagemagick.org

I see that is indeed quite old. I will upgrade and try again.

MV

[vmartin]

After upgrading to

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Version: ImageMagick 7.0.5-4 Q16 x86_64 2017-04-01 http://www.imagemagick.org

ColorSpace is reported as sRGB as expected

Thanks again
MV