"PDF Comparison" Option

Use this option if you wish to compare processed pages with the original documents or the pages not yet processed in the Prinect workflow. This lets you detect changes to the contents, resulting from processing in the Prinect workflow. For the PDF comparison, bitmap images are generated from the original and the edited PDF pages respectively, which are compared with each other. The resolution for the overview images can be set (see below). The higher the resolution, the more accurate the comparison, but the computing effort also increases with the square of the resolution.

When pages are submitted to a Prepare sequence and "PDF Comparison" is enabled, the oldest available original pages are determined automatically. For the comparison, each page is transformed to the L*a*b* color space and screened with the set resolution.

Note: PDF comparison requires a lot of computing time, which delays job processing. Differences between the compared PDF pages that are not visually recognizable, such as spot colors converted to CMYK, are not taken into account when comparing. Also, differences smaller than 3 x 3 pixels are not taken into account.

"PDF Comparison" group

"Compare within the" list box

This is where you set the box (trim box, bleed box or art box) to which comparison will be confined.

Precision

You can set the accuracy to "Minimum", "Low", "Medium", "High" and "Maximum". The differences measured in Delta-E for a pixel in the color space are evaluated for this in the background. The selected level of accuracy determines the dimension of the Delta-E value used and whether a warning or an error will be reported if there is a deviation.

Resolution

The resolution determines the accuracy of the comparison and the time required for computing.

"Ignore 'Transparent' Colors" option

Transparent colors are not included in the comparison if you enable this option.

"Ignore 'DieLine' Colors" option

DieLine colors are not included in the comparison if you enable this option.

"Include PDF/X Output Intent" option

Normally, when you compare documents, any PDF/X Output Intent is removed temporarily from the documents so that it does not influence the comparison. However, noticeable deviations in the documents can result in Acrobat because of this.

The PDF/X Output Intent is included if you enable this option.

Calculation of differences

The following happens when you calculate the differences:

​•​The selected box from the page edited with this Prepare sequence is mapped to the older compare page. A warning is issued if the pages have different sizes.

​•​RGB images and the resulting L*a*b* images are calculated in the selected box of these two pages. Transparent or DieLine colors are ignored, depending on the option you set.

​•​The difference image is calculated from both images. Edge effects are eliminated to avoid errors that could result from rounding effects or spreading.

"Reporting" group

In this group you can set up how a test report with the result of the comparison will be created. The reports are filed as PDFs on the Prinect server to "PTJobs" and there to the subfolder of the print job concerned.

"Create Comparison Report" list box

This is where you set whether and when a comparison report will be created when "PDF Comparison" is enabled.

​•​Never

​•​If errors occur

​•​If at least warnings are given

​•​Always

"Language of the Report" list box

This is where you can set the language in which the comparison report will be generated. You can set one of the available languages by default or use "Language of the Report" to set that the report will be generated in the language set in the Cockpit user interface when the job was created.

"Report Template" option

Use "Browse" to select a report template file. This is then used as a template (page size, formatting, etc.) for automatic comparison reports. To be able to find a template file easily, it should be filed in a shared folder (PTJobs, PTConfig, PNTransfer) of the Prinect server or in a suitable subfolder.

You can set the dimensions and units of measure in the "Page format of the report", "Length unit in reports and messages" and "Resolution unit in reports and messages" list boxes.