SUNScholar/Media Filters/5.X

Back to Thumbnails

PLEASE NOTE:

• The media filters have changed by incorporating the use of ImageMagick and Ghostscript. See the link below for details about enabling media filters.

https://wiki.duraspace.org/display/DSDOC5x/ImageMagick+Media+Filters

• After a while we noticed our server load increasing radically when doing the nightly media-filter jobs.
• We isolated the problem to the "Branded Preview JPEG" filter.
• This filter has been disabled as these branded previews are not important to us.

Step 1 - Install the Ubuntu software packages

Type the following:

sudo apt-get install imagemagick ghostscript

Step 2 - Configuration

Edit the "dspace.cfg" file.

nano $HOME/source/dspace/config/dspace.cfg

Enable

Search for following and change to true:

webui.browse.thumbnail.show = true
webui.item.thumbnail.show = true
webui.preview.enabled = true

Dimensions

Check the value for thumbnail.maxwidth and that it corresponds to the size you want for preview images for the UI.

Search for the following and modify.

# maximum width and height of generated thumbnails
thumbnail.maxwidth  = 160
thumbnail.maxheight = 160

Filters

Enable filters as follows:

#Names of the enabled MediaFilter or FormatFilter plugins
filter.plugins = PDF Text Extractor, HTML Text Extractor, Word Text Extractor, \
                 PowerPoint Text Extractor, \
                 Branded Preview JPEG, \
                 ImageMagick Image Thumbnail, ImageMagick PDF Thumbnail

Names

Assign names for filters as follows:

#Assign 'human-understandable' names to each filter
plugin.named.org.dspace.app.mediafilter.FormatFilter = \
  org.dspace.app.mediafilter.PDFFilter = PDF Text Extractor, \
  org.dspace.app.mediafilter.HTMLFilter = HTML Text Extractor, \
  org.dspace.app.mediafilter.WordFilter = Word Text Extractor, \
  org.dspace.app.mediafilter.PowerPointFilter = PowerPoint Text Extractor, \
  org.dspace.app.mediafilter.BrandedPreviewJPEGFilter = Branded Preview JPEG, \
  org.dspace.app.mediafilter.ImageMagickImageThumbnailFilter = ImageMagick Image Thumbnail, \
  org.dspace.app.mediafilter.ImageMagickPdfThumbnailFilter = ImageMagick PDF Thumbnail

Input Formats

Assign MIME file types to media filters as follows:

#Configure each filter's input format(s)
filter.org.dspace.app.mediafilter.PDFFilter.inputFormats = Adobe PDF
filter.org.dspace.app.mediafilter.HTMLFilter.inputFormats = HTML, Text
filter.org.dspace.app.mediafilter.WordFilter.inputFormats = Microsoft Word
filter.org.dspace.app.mediafilter.PowerPointFilter.inputFormats = Microsoft Powerpoint, Microsoft Powerpoint XML
filter.org.dspace.app.mediafilter.BrandedPreviewJPEGFilter.inputFormats = BMP, GIF, JPEG, image/png
filter.org.dspace.app.mediafilter.ImageMagickImageThumbnailFilter.inputFormats = BMP, GIF, image/png, JPG, TIFF, JPEG, JPEG 2000
filter.org.dspace.app.mediafilter.ImageMagickPdfThumbnailFilter.inputFormats = Adobe PDF

Permissions

Configure media filter permissions. Search for "filter.org.dspace.app.mediafilter.publicPermission" and modify as follows:

#Publicly accessible thumbnails of restricted content.
#List the MediaFilter name's that would get publicly accessible permissions
#Any media filters not listed will instead inherit the permissions of the parent bitstream
filter.org.dspace.app.mediafilter.publicPermission = BrandedPreviewJPEGFilter, ImageMagickImageThumbnailFilter, ImageMagickPdfThumbnailFilter

List Emphasis

Search for xmlui.theme.mirage.item-list.emphasis. There are two options available namely "metadata" or "file", select "file".

See example below.

### Settings for Item lists in Mirage theme ###
# What should the emphasis be in the display of item lists?
# Possible values : 'file', 'metadata'. If your repository is
# used mainly for scientific papers 'metadata' is probably the
# best way. If you have a lot of images and other files 'file'
# will be the best starting point
# (metdata is the default value if this option is not specified)
xmlui.theme.mirage.item-list.emphasis = file

Save the "dspace.cfg" file and exit nano.

---

NANO Editor Help

CTL+O	= Save the file and then press Enter
CTL+X	= Exit "nano"
CTL+K	= Delete line
CTL+U	= Undelete line
CTL+W	= Search for %%string%%
CTL+\	= Search for %%string%% and replace with $$string$$
CTL+C	= Show line numbers

More info = http://en.wikipedia.org/wiki/Nano_(text_editor)

---

Step 5 - Test the media filers

Type the following to test. Select an item that has pdf files attached and use it as replacement for "123456789/29097".

$HOME/bin/dspace filter-media -v -i 123456789/29097

Step 6 - Create new thumbnails

The script is configured to do 1000 items at a time only. This saves on memory and CPU time. Therefore on a large system you may need to run the script several times. Also make sure that the dspace user has full read/write access to all items in the asset store folders.

$HOME/bin/dspace filter-media -v -f -m 1000 -p "ImageMagick PDF Thumbnail"

$HOME/bin/dspace filter-media -v -f -m 1000 -p "ImageMagick Image Thumbnail"

Step 7 - Add a daily admin task

See: http://wiki.lib.sun.ac.za/index.php/SUNScholar/Daily_Admin. Check the "filter-media" options!

References

• https://wiki.duraspace.org/display/DSDOC5x/Mediafilters+for+Transforming+DSpace+Content
• https://wiki.duraspace.org/display/DSDOC5x/Configuration+Reference#ConfigurationReference-XPDFFilter