Reduce file size
To send a PDF by email or make it available for a website, it is often necessary to reduce the file size. Acrobat offers this option via the File>Save as>Optimized PDF menu.
The menu item PDF with reduced size, with which one would rather associate the desired goal, is rather an expression of a somewhat unfortunate translation, as Adobe means a reduced version number for better downward compatibility (for users with older program versions).
The largest chunks in a file are always the images (as can easily be seen by clicking on the memory check button), which is why a recalculation achieves the greatest effect. If the default values set to Medium are not sufficient, you can also set the quality level to Low or even Minimal.
After clicking OK, save the file under a new name and you can now check what effect the optimization has had compared to the original file.
Remove hidden information
You can find another action in the toolbar in the Protection category. With the Remove hidden information routine, you can delete meta information from documents before passing them on to other people (e.g. by email).
By clicking on the entry, Acrobat immediately begins to search the document for hidden information. The status of this work is displayed on the left-hand side with a progress bar. However, the file is initially only searched for relevant information such as metadata, hidden text, links etc.; nothing is deleted at this stage.
Once the analysis is complete, the results are displayed in a clear list in the form of a tree structure that can be expanded and allows a preview of the relevant information. Components of the search results that should not be removed from the file (e.g. bookmarks) can be specifically deselected by removing the checkmark in front of them.
To finally delete the remaining information, click on the Remove button.
Clean up document
This command removes all meta information, including bookmarks, from the file. A selection is not provided. The document must therefore also be saved again. This is to ensure that all meta information has really been removed from a document before it is forwarded.
Optimize scanned file
In the Document processing category in the toolbar (and in the action wizard), you will find an action for optimizing scanned documents. Clicking on it opens a window in which you can adjust details if required.
Details on the default settings of the filters for removing distortion, background etc. as well as the OCR options can be checked and adjusted if necessary using the Edit buttons.
Compare documents
If a file has been changed, it is usually difficult to recognize the differences to the older version. Details are easily overlooked during the visual check. Acrobat provides the Compare documents action for this requirement. You can find it in the Display menu.
In the window that opens, you can use the Select button to select the file with which the open document is to be compared.
In the Document description section, you can select whether it contains mainly text, images or a mixture of both. Acrobat then uses different analysis algorithms in each case.
A tick in the Compare text only checkbox ensures that images and graphics are not included in the analysis.
After clicking OK, Acrobat analyzes the two documents and then opens a summary. To the left of this, you will find a new Compare button in the navigation bar on the left-hand side of the screen . Here you can make changes to the color scheme (this can be useful if the document uses colors that make it difficult to see the markers to display the differences found) and the opacity. If required, you can also create your own new color scheme.
The options button takes you to further setting options, e.g. you can display both documents to be compared side by side (if the display size is large enough).
To check the differences in detail, click on Start: First change on page 1.
Acrobat will now display the first page in the document on which changes have been analyzed. These are marked in different colors, for which a legend is displayed (can be closed using the close button). To get more space for the display, you can also close the compare barby clicking on the small arrow. The selected changes contain notes with the changes made and are displayed as a mouseover.
For a better overview, you can also show the comment bar on the right-hand side, in which all changes are clearly documented one below the other.
To show the compare baron the left-hand side again, simply click on the corresponding button in the navigation bar.
