ImageDctHashSearchCriteria

ImageDctHashSearchCriteria class

Represents a search criteria for finding images in a document.

public class ImageDctHashSearchCriteria : ImageSearchCriteria

Constructors

Name	Description
ImageDctHashSearchCriteria(Stream)	Initializes a new instance of the `ImageDctHashSearchCriteria` class with a specified stream.
ImageDctHashSearchCriteria(string)	Initializes a new instance of the `ImageDctHashSearchCriteria` class with a specified file path.

Properties

Name	Description
MaxDifference { get; set; }	Gets or sets maximum allowed difference between images.

Methods

Name	Description
And(SearchCriteria)	Combines this `SearchCriteria` with other criteria using logical AND operator.
Not()	Negates this `SearchCriteria`.
Or(SearchCriteria)	Combines this `SearchCriteria` with other criteria using logical OR operator.

Remarks

This search criteria uses DCT based perceptual image hash for calculating image similarity. Learn more:

Searching watermarks

Examples

Search for images in the attached files (pdf).

WatermarkerSettings settings = new WatermarkerSettings();
settings.SearchableObjects = new SearchableObjects
{
    PdfSearchableObjects = PdfSearchableObjects.All
};
PdfLoadOptions loadOptions = new PdfLoadOptions();
using (Watermarker watermarker = new Watermarker(@"D:\test.pdf", loadOptions, settings))
{
    // Specify sample image to compare document images with
    ImageSearchCriteria criteria = new ImageDctHashSearchCriteria(@"D:\sample.png");
    // Search for similar images
    PossibleWatermarkCollection possibleWatermarks = watermarker.Search(criteria);
    // Remove or modify found image watermarks
    // ...
}