Author Topic: image dimensions  (Read 4971 times)

Offline pdlarry

  • Newcomer
  • *
  • Posts: 18
    • View Profile
image dimensions
« on: August 04, 2007, 11:51:00 PM »

Newbie has another question

Why does PM display 3904x2616 when my image is 3872x2592?  32 too wide and 24 too tall?!

Thx

Offline Kirk Baker

  • Senior Software Engineer
  • Camera Bits Staff
  • Superhero Member
  • *****
  • Posts: 24817
    • View Profile
    • Camera Bits, Inc.
Re: image dimensions
« Reply #1 on: August 05, 2007, 12:21:23 AM »
Newbie has another question

Why does PM display 3904x2616 when my image is 3872x2592?  32 too wide and 24 too tall?!

More information would be helpful about the file type, PM version, and OS version, but I'm guessing it is because of the disparity between the Exif dimensions and the renderable dimensions of the image.

-Kirk

Offline Hayo Baan

  • Uber Member
  • ******
  • Posts: 2552
  • Professional Photographer & Software Developer
    • View Profile
    • Hayo Baan - Photography
Re: image dimensions
« Reply #2 on: August 05, 2007, 04:17:38 AM »
Kirk,

I think I know what's going on here: with RAW files, PM reports the pure RAW sensor photosites.  The resulting (bayer interpolated) image is always somewhat smaller.
Some examples:
  • a D70 image is 3008x2000 pixels but has a sensor of 3040x2014 photosites
  • a D200 image is 3904x2616 pixels but has a sensor of 3872x2592 photosites

Note: I have put forward a feature request to (also) show the size of the embedded JPG (http://forums.camerabits.com/index.php?topic=1931.msg8759#msg8759)
Hayo Baan - Photography
Web: www.hayobaan.nl

Offline pdlarry

  • Newcomer
  • *
  • Posts: 18
    • View Profile
Re: image dimensions
« Reply #3 on: August 05, 2007, 02:16:42 PM »

D200 Raw files, WinXP, PM4.5.1.1


Offline pdlarry

  • Newcomer
  • *
  • Posts: 18
    • View Profile
Re: image dimensions
« Reply #4 on: August 06, 2007, 10:15:50 AM »
Kirk,

I'd expect PM to report 3872x2592 so it conforms to what's stated in the camera user manual?

PD

Offline Kirk Baker

  • Senior Software Engineer
  • Camera Bits Staff
  • Superhero Member
  • *****
  • Posts: 24817
    • View Profile
    • Camera Bits, Inc.
Re: image dimensions
« Reply #5 on: August 06, 2007, 11:33:44 AM »
I'd expect PM to report 3872x2592 so it conforms to what's stated in the camera user manual?

We report what the camera puts into the Exif data.

-Kirk

Offline pdlarry

  • Newcomer
  • *
  • Posts: 18
    • View Profile
Re: image dimensions
« Reply #6 on: August 06, 2007, 11:41:59 AM »
Kirk,

In the case of RAW files, is there one or two sets of Exif info?  If I extract the JPEG preview from the RAW, I get the 3872x2592.

Thanks.

Larry

Offline Hayo Baan

  • Uber Member
  • ******
  • Posts: 2552
  • Professional Photographer & Software Developer
    • View Profile
    • Hayo Baan - Photography
Re: image dimensions
« Reply #7 on: August 07, 2007, 09:13:46 AM »
Kirk points out where the problem lies: the EXIF data in fact does report the higher values.  And as I said, this is also correct; it's the size of the RAW data.  The resulting image size after the necessary interpolation is slightly smaller, and this is in fact what we want to know in the case described here (and in my feature request).

Note: Nikon camera's include a full res jpg preview, but I'm not sure about other cameras.  So always and only showing the size of the embedded jpg may not give the expected results.
By the way: Nikon Capture 4 included a lower resolution image, so for this purpose this wouldn't work either...
Hayo Baan - Photography
Web: www.hayobaan.nl

Offline pdlarry

  • Newcomer
  • *
  • Posts: 18
    • View Profile
Re: image dimensions
« Reply #8 on: August 07, 2007, 09:56:29 AM »
Hayo, Kirk,

Thanks for the info.  Now that I know why it's doing that I feel better.  Not a big deal really. 

Got PM for its blazing speed; no complaints there :)

PD