ImageStore use pHash to find the similar image files.
To detect similar files, first add all files being checked to database, second call Measure-ImageStoreFile or Measure-ImageStoreFiles to calculate Sha1 hash, then call Compare-ImageStoreSimilarFiles to find all similar relationships.
Resolve-ImageStoreSimilarFiles will group the similar relationships and display them with a UI.
Note: Thumbprint cache may be useful while you calling Resolve-ImageStoreSimilarFiles repeatedly.
While running Resolve-ImageStoreSimilarFiles, all relations which have a difference degree not larger than the parameter specified will be used to group files into similar file groups.
For example, there are 6 files: A, B, C, D, E and F. The difference degree between A and B is 0.01, between B and C is 0.02, between A and C is 0.1, between C and D is 0.5, between E and F is 0.2. While running Resolve-ImageStoreSimilarFiles with parameter DifferenceDegree set as 0.02, there will be only one group founded, which contains A, B and C. Though the relation between A and C are not considered, but the relations of B connected them; if the parameter DifferenceDegree set as 0.2, there will be one more group found also, which contains E and F.
There are 2 types of the ignored states:
- If the similar relation is correct, but you want to hide this relation from further processing, choose: Hidden but Connected.
- If the similar relation is not correct, choose: Hidden and Disconnected.
The different between this 2 modes, is whether the connection is still valid.
For example, there are 4 files A, B, C and D are connected by effective similar file relations A-B, B-C, C-D. If the record of B-C is set to Hidden but Connected or not ignored, these 4 files are still will be grouped into one similar file group next time. But if it's set to Hidden and Disconnected, in next time grouping, there will be 2 groups contains A and B, C and D, instead of one.
All files checked in Resolve-ImageStoreSimilarFiles](SimilarFile/ResolveSimilarFiles.md) will be returned. Combines the result with Remove-ImageStoreFile to delete the files chosen.
- To check or modify Similar Files, you need to call Similar File Cmdlets.