User manual

DV-IP User Manual v1.01 Feb 28
th
2003
DV-IP User Manual
37
Watermarking
This page is used to examine the video partition index information and to generate
Watermark certificates. These watermarks prove that an image has not been altered or
tampered with by producing MD5 signatures that change if any alterations are made to the
image files.
To watermark images, follow the steps below:
The time range is set up using the "Start time and date" and "End time and date".
When the time period has been set up the partition information can be uploaded by pressing
the "Partition info" button. The selection window will then display the partition information
covering the specified time period.
If an individual partition is selected, it's index information can be viewed by selecting the "get
Index Info" button.
The watermark codes are generated by pressing the "Watermark" button. The step size
through the partition is specified in the "Watermark step size" text box. This specifies the skip
distance between bytes used in the watermark calculation e.g. A step of 1 uses every byte in
the video partition in the watermark calculation. A smaller step size results in a longer
calculation time. Progress/completion is indicated by messages in the status bar.
After generating the watermark codes, A certificate can be created by pressing the "Create
Certificate" button. If required, the report author's name should be entered in the "Report
Author" text box.
The certificate can be printed out if required.