Thumbnails for items

Hello Omeka Users/Developers!

I am writing to you in hope of finding an anaswer to my problem that I have with your wonderful software. I really need th epictures and files to have thumbnails, but the only ones i keep seeing are the standard ones. I installed the DerivativeImage plugin, but no success. I was even able to change one of the standard thumbnails to show something i want. But i need seperate thumbnails for almost very file/item i create. Does Omeka have a feature to make thumbails from files? If not how can i make one?

Respectfully,

Maks Kremer

Could you tell more about what exactly you need, distinct from the thumbnails that Omeka already generates? Omeka produces both square thumbnails and thumbnails that maintain the relative dimensions of the files.

Or, are the thumbnails you are seeing just the generic fallback images that don't really look like they come from your files?

Thank you for your quick answer, sadly its just generic fallback images. I read somewhere that omeka can only generate thumbnails of very specific formats, could you please list them? My images are png bmp and jpg

Also I really need the items to show up as a grid, but not as an exhibit. Right now when i search through items or browse them they all show up as a list, I need them to be a grid (prefferably a grid that could auto-adjust according depending on the user's browser window). Please help me on both these issues. I need this as soon as possible, would really appreciate a quick response like the first one.

Omeka can produce thumbnails for a pretty wide variety of formats. Omeka just uses ImageMagick to create those thumbnails, so for current versions of Omeka, it can make a thumbnail out of pretty much anything ImageMagick knows how to read.

So, the amount of support depends on what the ImageMagick installed on your server supports. Pretty much any install will do the "normal" image formats like JPG, but ImageMagick can also be set up to make thumbnails of videos, PDFs, text files, and other documents.

What Omeka can and cannot generate derivative images for really depends on the underlying ImageMagick application we use. Usually, it handles a wide range of formats -- all those image formats usually work.

Since those aren't being generated, the first thing I'd check is that Omeka knows where to find ImageMagick. Under the general settings, scroll to the bottom and test whether the path to ImageMagick is correct.

Did that long before posting to this forum. it writes that the path works and everything is fine. I am assuming that the problem might be with the imagemagick itself, but since the server and ImageMagick installation was done by our companies experienced system administrator, it is possible that that might not be the case.

Maybe someone could guide me through the process of creating and choosing a thumbnail, or is that something that Omeka is just supposed to do by itself(and post the thumbnails instead of the generic ones)? Thank you for all the interest and help in this topic.

Yes, Omeka should be generating the thumbnails automatically. The generic ones are used when for some reason Imagemagick can't generate one.

The next step might be to turn on error logging, and try to save a new item with an image. Hopefully, info about what's happening (or not) will be in the error logs.

If an example image is available somewhere, I could also try it one of my dev sites and see if I can get info about it.

Thank you for the suggestion, I did that, error log is empty, because if i'm not mistaken Omeka doesn't see this as an error. It automatically takes the fallback image and thinks that everything is just fine. I'm just using random sample images right now, just ocean view, desktop backgrounds, i just need an example of a digital library at this point.

Ok, got everything working. I didn't save the path of the ImageMagick after i changed it to a path that works. Uploaded a new fle just now everything works. So happy now.

Still the questions of how to display items as a grid exists though.

Hi,

I have the same need for a specific project (a wall of very small thumbnails in particular). So, if you need more derivative types than the default ones, I made a small patch (https://github.com/omeka/Omeka/pull/638) to Omeka for that. Next, you can easily define some specific class has explained above.

Sincerely,

Daniel Berthereau
Infodoc & Knowledge management

Daniel:
Does your patch allow for users to navigate from one image to the next once they select the thumbnail? Or does it open the image bare, in the browser window, requiring one to back-arrow to return to the Omeka interface?
I'm stymied with apparent glitches in the two standard image viewers people have used in the past. Wondering if this might be a solution.

Hi,

This is not the same question. My patch allows to manage more than the three default derivatives types (normal thumbnail, square thumbnail and fullsize). Next, theme has to be modified.

Here, you want a viewer to browse images in the same window, like a manual carousel. For that, you can choose any javascript snippet on the web and integrate it in your theme too.

Sincerely,

Daniel Berthereau
Infodoc & Knowledge management

Hello again,

I am not a programmer (yet) so sadly i do not understand how to implement your patch. It would be very nice if you could post something like a howto to do it. Also, does Omeka (using Imagemagick) make thumbnails from .docx and .doc files? If not where would i be able to find a way to get it to do that?

Respectfully,

Maks Kremer

P.S. I need it to either choose a first image in the document and make a thumbnail from that or just make a thumbail displaying some tiny text.

imagemagick will try to make thumbnails of any file it knows how to work with, but variations in the file and imagemagick version can produce different results.

Hi,

I don't think you need my patch, because you just need a thumbnail for each uploaded file. This is made by default in Omeka if your server has ImageMagick installed as php extension or as a command line tool. To check if the extension is installed, you can look if imagick exists in http://www.example.com/admin/system-info. For the command line tool, check at the bottom of the page http://www.example.com/admin/settings/edit-settings. You should choose one of these libraries and set it in the config.ini (fileDerivatives.strategy).

If ImageMagick is not installed, you can use the GD library (https://github.com/Daniel-KM/Omeka/blob/gd_derivatives/application/libraries/Omeka/File/Derivative/Strategy/GD.php), that has been pulled at https://github.com/omeka/Omeka/pull/645. GD is more common on shared or old servers than Imagick.

If your files are not images and are not standard or if you want a specific transformation, copy and adapt this file to your needs.

Sincerely,

Daniel Berthereau
Infodoc & Knowledge management

Hello again,

Imagemagick works perfectly it creates thumbnails from many different files (even PDF), but not from .doc and .docx . I got everything working except for that.

Thank you for your help,

Respectfully,

Maks Kremer

Imagemagick doesn't support .doc or .docx. To get it to work, you would have to write a Strategy that first converted the files to PDF, then extracted the first page as a thumbnail.

http://omeka.readthedocs.org/en/latest/Tutorials/derivativeStrategies.html

I am having this same problem. ImageMagick is installed on my shared hosting server. Here are the settings:
System
Omeka 2.3
PHP 5.4.43 (cgi-fcgi)
OS Linux 3.12.35.1418868451 x86_64
MySQL Server 5.5.42
MySQL Client 5.5.42-37.1
PHP Extensions
Regular bcmath, bz2, calendar, cgi-fcgi, Core, ctype, curl, date, dom, ereg, exif, fileinfo, filter, ftp, gd, gettext, gmp, hash, iconv, imagick, imap, intl, ionCube Loader, json, libxml, mbstring, mcrypt, mhash, mssql, mysql, mysqli, odbc, openssl, pcre, PDO, pdo_mysql, pdo_sqlite, Phar, posix, pspell, Reflection, session, SimpleXML, soap, sockets, SourceGuardian, SPL, sqlite3, standard, tidy, tokenizer, wddx, xml, xmlreader, xmlrpc, xmlwriter, xsl, Zend Guard Loader, zip, zlib
Zend the ionCube PHP Loader, Zend Guard Loader
The ImageMagick Directory Path is /usr/bin and when I click test it returns "The ImageMagick directory path works."
Yet, it creates no thumbnail for my MP4 video files.
I am at a loss of what to do. Any suggestions are very welcome.
John

If it is just for the MP4 files, my first guess is that the version of imagemagick on your server might not know how to create derivatives for that file type. Do you know what version you have installed?

You might also try switching the thumbnail creation strategy in the configuration.