The Compare Documents feature is used to compare two PDFs and highlight the differences. The differences are indicated with markups that can be reviewed easily using the Markups list.
This feature is similar to Overlay Pages, which converts two or more PDFs to different colors and stacks them one on top of the other to reveal differences. Use the one that most closely matches your desired outcome.
Note: The Overlay function works well for PDFs with vector graphics, while Compare Documents is best suited for working with scanned images or drawings.
Go to Document > Compare Documents. The Compare Documents dialog box appears.
- Select the first document to be compared in the Document A section:
- If the document is currently open in Revu, select it from the Document dropdown list in the Document A section.
- If the document is not currently open in Revu, click to the right of the Document dropdown list in the Document A section, then navigate to and open the desired document.
Select the Page Range that should be compared:
- All Pages: Sets the range to all pages.
- Current: Sets the range to the current page only. The current page number will appear in parentheses, for example, Current (2) if page 2 is the current page.
- Custom: Sets the range to a custom value.
When this option is selected, the field acts like a text box. Delete any text left in the field and enter the page or pages to be printed directly.To enter a custom range:
- Use a dash between page numbers to define those two pages and all pages in between.
- Use a comma to define pages that are separated.
For example: 1-3, 5, 9 will include pages 1, 2, 3, 5 and 9.
- Repeat this process for Document B.
- Select the local, network, or DMS folder into which the comparison document should be saved by entering the path to that folder in the Output Folderfield or by clicking to the right of that field and navigating to the desired folder.
- If you want to
compare only a specific region of each document, click Select Window. The dialog box will disappear, at which time you can click and drag a rectangle to define the region to be compared. Otherwise the entire document will be compared.
- Click Clear to clear the selected window and start over, if needed.
- By default Revu will attempt to line up the documents. If you wish to override the automatic alignment, click Pick Points to specify the alignment points. You will need to pick three points on each document and the points should be specified in a clockwise order and the alignment points should correspond to one another; for example, Selection Point 1 on Document A should correspond to Selection Point 1 on Document B.
- Click Clear to clear the selected points and start over, if needed.
- To open side-by-side, synchronized windows for reviewing the differences noted after the comparison process completes, check Split-screen view.
- To dim underlying PDF content and make the locations where differences are found easier to see, check Turn on Dimmer.
- Select a Comparison Type containing pre-configured comparison settings.
These settings can be customized by clicking Advanced. See Advanced Comparison Options below for more information.
Click OK. Once the comparison process is complete, any differences will be annotated.
If the Split-screen view box was checked, the two compared documents will open in a side-by-side manner. Zooming or panning on one window will update the display in the opposite window. This is useful for visually comparing the before/after, changed, and unchanged parts of the two documents. The markups that were added will appear in either the left or right window depending on which PDF was specified.
Open the Markups List to see a table of markups that were automatically added when differences were detected.
As a markup is selected in the Markups list, the Revu workspace will jump to the location of the difference.
Use the Advanced Comparison Options to fine-tune the document comparison process. It is recommended that you use the default Comparison and Rendering settings provided and change these settings only if the document comparison process does not appear to detect differences.
Three default comparison Types are provided: Printed Documents (same printer), Printed Documents (different printer) and Scanned Documents. Each Type has pre-configured Comparison settings. You can change the settings of any of the default Types or create a custom Type by selecting <New Custom>. The Advanced Comparison Options are:
- The comparison process breaks the document into a region of grids for comparison. Grid Size defines the size of the individual grid segments used for comparison. These regions are then inspected for different pixels to identify as a differing region.
- Pixel Density controls the threshold amount of differences in a particular area (defined by the Grid Size) when detecting differences.
- Color Sensitivity helps to determine the threshold at which pixel differences will be determined. A lower sensitivity setting will not detect as many differences as a higher sensitivity setting.
- This setting works in conjunction with the Pixel Proximity Allowance. Increase this value to check adjoining areas for similar pixels.
- Set the Margin value to ignore regions around the borders of the PDFs being compared.
- Enter values in the Offset setting if you know one document is offset from the document that is being compared. Likewise, you may check Auto-alignment to instruct Revu to automatically align the drawings or documents that are being compared. Auto-alignment is recommended for comparing scanned drawings.
- DPI determines the resolution used to rasterize the PDFs. The default setting is 72. Set the value higher (144) if finer resolution is needed for the comparison.
- By default, the comparison tool ignores existing markups on the documents, since these can already be easily located via the Markups list. Select Include Markups to override this behavior and render markups for comparison.
- While flattened markups become part of the PDF's content layer, the comparison tool ignores those that have been flattened as "recoverable" by default. Select Include Flattened Markups to override this behavior.
- Determine the appearance of the markups that will be used to annotate differences found during the comparison by setting the Color, Fill Color, Opacity and Width. If cloud markups should be used, check Cloud.
- If the annotations should be locked when they are placed, check Locked.
- Enter a name for the difference annotations (for example, “Differences 5-7-14”) in the Subject field, if desired. This makes it easy to group the difference annotations together on the Markups list by sorting by Subject. A series of difference comparisons can be made over time to provide a change history.
- Select which document the difference annotations should be added to from the Apply to dropdown list. If one of the "New copy" options is selected, a new document containing the difference annotations will be created based on the indicated document. Otherwise, the difference annotations will be added to the selected document(s).
- Enter a File Suffix that will be appended to the comparison document file name generated during the comparison process. This will make it easier to differentiate the comparison document from the originals.
If you change a value in a default comparison Type, its name is marked with an asterisk (*).
To change the settings of the current type permanently, click Save. The Save Document Comparison Settings dialog box will open. Enter a name for this configuration. If you are changing the settings of a default Type, its name will be auto-populated; you can save it under the default name or change it, creating a new type.
To restore the included types to their default settings, click Restore Defaults.