I opened up my sd card and caja doesn't preview some of the pictures. so I
checked th files' size and they were less than 10MBs but the file size to
preview was set to 10MB. I increased it to 1G anyways, refreshed the page,
and bam! the files previewed. I thought that was great. Then I transferred
the files from the card to the computer and once the files had been
transferred they wouldn't preview. I again checked the preview file size to
ensure it hadn't changed but it was still set to 1G. I then decreased and
then increased the preview file size but that didn't help any. So what's
wrong?

I found this but wasn't sure it still applied seeing as how I got them to
preview before transferring them and this is for the previous version of
Mint; Mint12.
Currently I run mint13 on a 32 bit comaq cq57. I was also thinking it
didn;t apply because the new filemanager is caja and not nautilus.

what found:

Modern cameras can store raw images which are a must for a serious
photographer. Unfortunately raw image previews are not shown by Gnome's
file manager Nautilus.

However, there is already a workaround type of solution for this. I will
describe it in four steps.


Step 1:
Install gnome-raw-thumbnailer package.


Step 2:
Create a file /usr/share/thumbnailers/raw.thumbnailer

Step 3:
Put in these lines:

Exec=/usr/bin/gnome-raw-thumbnailer -s %s %u %o
MimeType=image/x-3fr;image/x-adobe-dng;image/x-arw;image/x-bay;image/x-canon-cr2;image/x-canon-crw;image/x-cap;image/x-cr2;image/x-crw;image/x-dcr;image/x-dcraw;image/x-dcs;image/x-dng;image/x-drf;image/x-eip;image/x-erf;image/x-fff;image/x-fuji-raf;image/x-iiq;image/x-k25;image/x-kdc;image/x-mef;image/x-minolta-mrw;image/x-mos;image/x-mrw;image/x-nef;image/x-nikon-nef;image/x-nrw;image/x-olympus-orf;image/x-orf;image/x-panasonic-raw;image/x-pef;image/x-pentax-pef;image/x-ptx;image/x-pxn;image/x-r3d;image/x-raf;image/x-raw;image/x-rw2;image/x-rwl;image/x-rwz;image/x-sigma-x3f;image/x-sony-arw;image/x-sony-sr2;image/x-sony-srf;image/x-sr2;image/x-srf;image/x-x3f;

(Steps 1, 2 and 3:)
http://ubuntuguide.net/raw-cr2-image-pr ...
-thumbnail<http://ubuntuguide.net/raw-cr2-image-preview-in-gnome-nautilus-using-gnome-raw-thumbnail>

Step 4:
Nautilus/Settings/Preview
Set Max Size to something more suitable than it is now by default. For
example, there are options for 1, 5, 10 and 100Mb. My camera's raw images
are 15 Mb so I have to choose 100Mb.

This worked with 64-bit Mint 12.

:-)~MIKE~(-: