SEO

#1 (**permalink**) 01-18-2008, 04:36 PM

Hi, all.

I have a couple of digital cameras. they show up as external discs, and I
use Nautilus to copy the images over to my computer, where I work on them
with Gimp.

I wrote to short scripts to rotate the images, but it occured to me that
some cameras store the orientation of the image.

I can see this if I ask Nautilus to display the contents of a directory as
an "Image Collection". I see a panel on the right hand side with a field
"Orientation"; normal orientation is "top - left", and if I turn the
camera on its side before shooting, this is noted as "left - bottom", for
example.

So, instead of manually looking through the images, and rotating them, I
could write a script that reads the orientation from the file, and
automatically rotates those images that require it.

But, I tried looking at a JPEG file using "strings img_01.jpg | more" and
while this showed some information, orientation was not there.

Nor was it marked when I clicked MB3 on a file, chose Properties, Image
tab.

How can I extract the orientation information from a JPEG?

Beef.

#2 (**permalink**) 01-18-2008, 04:36 PM

25 Jan 2006 19:34 UTC, Beef typed:
> I wrote to short scripts to rotate the images, but it occured to me that
> some cameras store the orientation of the image.

Have a look at one of the programs that can read EXIF data. 'exif' or
'exiftags' for example.

'exif *.jpg |grep Orientation'

yields a list that you could utilise in a script to rotate automatically.

Did you have to enable the orientation sensing in the camera? I've been
looking at some pics taken by someone else using a Fuji A330. They're
mixed landscape and portrait format, yet the output of the above command
reports 'Top, Left-Hand' for all.

#3 (**permalink**) 01-18-2008, 04:36 PM

On Wed, 25 Jan 2006 22:03:23 +0000, Chiefy wrote:

> 25 Jan 2006 19:34 UTC, Beef typed:
>> I wrote to short scripts to rotate the images, but it occured to me that
>> some cameras store the orientation of the image.
>
> Have a look at one of the programs that can read EXIF data. 'exif' or
> 'exiftags' for example.
>
> 'exif *.jpg |grep Orientation'
>
> yields a list that you could utilise in a script to rotate automatically.
>
> Did you have to enable the orientation sensing in the camera? I've been
> looking at some pics taken by someone else using a Fuji A330. They're
> mixed landscape and portrait format, yet the output of the above command
> reports 'Top, Left-Hand' for all.

Thanks, that looks to be exactly what I want.

Looking around, I find that there's a program called jpegexiforient that
would probably take care of rotating the images.

Beef.

#4 (**permalink**) 01-18-2008, 04:36 PM

On Wed, 25 Jan 2006 22:03:23 +0000, Chiefy wrote:

> 25 Jan 2006 19:34 UTC, Beef typed:
>> I wrote to short scripts to rotate the images, but it occured to me
>> that some cameras store the orientation of the image.
>
> Have a look at one of the programs that can read EXIF data. 'exif' or
> 'exiftags' for example.
>
> 'exif *.jpg |grep Orientation'
>
> yields a list that you could utilise in a script to rotate
> automatically.
>
> Did you have to enable the orientation sensing in the camera? I've been
> looking at some pics taken by someone else using a Fuji A330. They're
> mixed landscape and portrait format, yet the output of the above command
> reports 'Top, Left-Hand' for all.

I've had a quick look at some of my photos using exiftags.

Pictures taken with my old Sony camcorder all have the same value for the
orientation field, regardless of the way I held the camera.

Pictures taken with my newer Canon have a correct value for this field.

My scripts use convert to rotate the image; the field is not updated.

Thanks for your help,

Beef.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

SEO

Nautilus and images