- 
Although it is not mentioned in Help page Starting LibreOffice Software With Parameters, I was able to make the export of a ODP Impress file as HTML thru command-line. My code was: libreoffice --convert-to html ejemplo.odpSo, this extra filter MUST BE mentioned in Help page, as well in documentation, specially now that the Export to HTML menu has been removed. 
- 
Besides, on that pages it is not clear what are the parameters for the other filters (there are some examples, but pointing to the complete list for each filter would be better). 
- 
In command-line help for libreoffice command, still you can see the option --convert-images-to, but I was truly unable to use it, to extract the images. (I’m already aware of the extension for that purpose). Either must be out if the command-line help to avoid confusions (maybe this functionality has been deprecated), or the command-line help must be very specific in it usage.Here’s what you can read in command-line help ( $ libreoffice --help)
 --convert-to OutputFileExtension[:OutputFilterName] \                      
     [--outdir output_dir] [--convert-images-to]                               
                       Batch convert files (implies --headless). If --outdir   
                       isn't specified, then current working directory is used 
                       as output_dir. If --convert-images-to is given, its     
                       parameter is taken as the target filter format for *all*
                       images written to the output format. If --convert-to is 
                       used more than once, the last value of                  
                       OutputFileExtension[:OutputFilterName] is effective. If 
                       --outdir is used more than once, only its last value is 
                       effective. For example:                                 
                   --convert-to pdf *.odt                                      
                   --convert-to epub *.doc                                     
                   --convert-to pdf:writer_pdf_Export --outdir /home/user *.doc
                   --convert-to "html:XHTML Writer File:UTF8" \             
                                --convert-images-to "jpg" *.doc              
                   --convert-to "txt:Text (encoded):UTF8" *.doc
