The scaling factor can be given in the config file. When this changes,
images can be regenerated via POSTing to certain endpoints. It is
possible to regenerate just one attachment preview or all within a
collective.
There is a task to generate preview images per attachment. It can
either add them (if not present yet) or overwrite them (e.g. some
config has changed).
There is a task that selects all attachments without previews and
submits a task to create it. This is submitted on start automatically
to generate previews for all existing attachments.
This is the first available preview of an attachment wrt position. If
all attachments have a preview image, the preview of the first
attachment is returned.
For images the conversion also returns the extracted text. If this
would have failed to be saved, it is extracted in the following
text-extraction step.
The server accepts a list of tag categories for inclusion and
exclusion. The categories in the include list imply to return items
that have at least one tag of each category. The categories in the
exclude list imply to return all items that have no tag in any of
these categories.
- Use another external tool to convert pdf to pdf which also adds the
extracted text as another layer into the pdf
- Although not used, the external conversion routine will now check
for an existing text file that is named as the pdf file with extension
`.txt`. If present it is included in the conversion result and will be
used as the extracted text.
- text extraction for pdf files happens now on the converted file,
because it may already contain the text from the conversion step and
thus avoids running OCR twice.
- All errors during conversion are not fatal; processing continues
without a converted file.
