Cacher is the code snippet organizer for pro developers

// For complete examples and data files, please go to https://github.com/groupdocs-watermark/GroupDocs.Watermark-for-.NET
using (Document doc = Document.Load(Utilities.MapSourceFilePath (PptFilePath)))
{
    // Initialize criteria with the image
    ImageSearchCriteria imageSearchCriteria = new ImageDctHashSearchCriteria(@"D:\watermark.jpg");

    //Set maximum allowed difference between images
    imageSearchCriteria.MaxDifference = 0.9;

    PossibleWatermarkCollection possibleWatermarks = doc.FindWatermarks(imageSearchCriteria);
}