In v2015R1, Qoppa added an optional module to our PDF editing and annotating component jPDFEditor that allows to compare 2 PDF documents or drawings by by overlaying / superimposing them. 

Compare Overlay allows to superimpose 2 drawings or documents and immediately identify the differences using color coding:

  • Elements present only in first drawing appear in red (customizable color).
  • Elements present only in second drawing appear in green (customizable color).
  • Alignment tools allow moving and resizing second document dynamically for perfect match.
  • Option to export the overlay comparison as a new PDF, with the 2 drawings included as layers.
    At any time during the comparison, using the toolbar, annotate or markup onto the main document (Document A).
  • Switch over to the Side by Side Comparison mode by clicking on the “Side by Side” button in the Overlay Comparison dialog.
Compare Overlay
Compare Overlay superimposes 2 PDF documents and allows to identify the differences in the documents using color coding.

 

Comparison Adjustment Options

The following adjustment options are available:

  • View – choose to display both or each document individually
  • Color – select the color of each document (the default colors generally provide the best results). Read our KB entry regarding Choosing colors for overlay PDF comparison.
  • X & Y – adjust the X & Y values of Document B to move it left, right, up, or down
  • Rotate – adjust the rotation of Document B if needed
  • Scale – make Document B smaller or larger if needed


Exporting Comparison as a PDF

The comparison can be exported as a single document with the overlay as the base layer and Documents A & B as layers within the document. To export, click on the “Export” button in the “Compare Overlay” dialog.

  • The overlay comparison view will be rasterized (turned into an image per page) as the base layer.
  • The original Document A – Layer 1
  • The original Document B – Layer 2


Exiting Comparison Mode

To exit the comparison mode, just click on the “Close” button on the Overlay Compare dialog to return back to Document A.

Contact info@qoppa.com if you’re interested in licensing this new module.