ImageStore

Image deduplication tool, optimized for large amount of pictures and CG libraries.

This tool is built as PowerShell cmdlets, providing user a flexible way to deal with large amount of image files (~1 million). Specially, it is optimized for CG libraries storing by allowing user to suppress the comparing among files in the same folder.

Requirements

• Windows.
• PowerShell 7.6 or later. The module targets .NET 10, and 7.6 is the first PowerShell release built on it.
• .NET 10 Desktop Runtime, which the windows opened by some cmdlets need. If Import-Module fails complaining about a missing framework, this is the one to install.

No database server is needed. A library is a single SQLite file, created by New-ImageStoreDatabase.

Note: Windows PowerShell 5.1 — the powershell.exe that ships with Windows — cannot load this module, because it runs on .NET Framework. Use pwsh. The last release that works under 5.1 is v2026.08.15.2.

Image Hashing Arithmetic

This tool use priHash, a C# Implementation of pHash (http://phash.org), based on phash-0.9.4 for Windows. In this tool, difference degree is based on the calculation of priHash.

Use Module in PowerShell

To use any module from dll in PowerShell, you just need 3 steps:

1. Start PowerShell by running pwsh.
2. Use command Import-Module to load module from dll file. The parameter of this command is the path of the dll file.
   Import-Module C:\ImageStore.dll will load the module file named as ImageStore.dll and placed in the root folder of drive C.
   Import-Module .\ImageStore.dll will load the module file named as ImageStore.dll from the current directory.
3. Use cmdlets.

Unpack the whole release archive into one folder and load ImageStore.dll from there. The other files beside it are its dependencies, and the module will not work without them.

Also, you can combine the step 1 and 2 as one, by passing the command as a parameter while starting PowerShell.
pwsh -noexit -command "Import-Module .\ImageStore.dll"

Note: Select-ImageStoreSameFile and Resolve-ImageStoreSimilarFiles open windows, which requires the host to run in a single-threaded apartment. pwsh does so by default, but the PowerShell Integrated Console in Visual Studio Code does not — run those two cmdlets from a real console.

Enable Information and Verbose Output

By default, the information and verbose level output will be silenced. ImageStore will report key information as informational output and progress updates as verbose one. Thus, enabling information output is highly recommended. If ImageStore is dealing with large amount of files, turning on verbose output is advised.

• Turn on information output: $InformationPreference="Continue"
• Turn on verbose output: $VerbosePreference="Continue"
• Turn off information output: $InformationPreference="SilentlyContinue", or simply restart PowerShell.
• Turn off verbose output: $VerbosePreference="SilentlyContinue", or simply restart PowerShell.

These setting will not be preserved among instances of PowerShell. Every time the PowerShell started, there are set as "SilentlyContinue".

Database

ImageStore stores everything in one SQLite file. There is nothing to install and no server to run, and each project has its own file.

Create one and start using it:

New-ImageStoreDatabase D:\Library\library.db

This creates the file, builds the schema and opens it, so no separate Open-ImageStoreDatabase is needed afterwards. Later sessions open the existing file:

Open-ImageStoreDatabase D:\Library\library.db

Keep the database file on a local disk. SQLite relies on file locking, which is unreliable over SMB and other network shares, and write-ahead logging cannot be used there at all. This is safe and normal even when the images themselves live on a NAS: the database stores paths, not image data, so the two do not have to sit together.

Upgrading from a Sql Server library

Releases before v2.0 kept data in Sql Server. To bring an existing library across, download ImageStore-Migrator from the release and run it once:

ImageStore.Migrator --source "server=(LocalDB)\MSSQLLocalDB;AttachDbFilename=D:\DataStore.mdf;Integrated Security=True" --target D:\Library\library.db

It copies every record and leaves the Sql Server database untouched, so the old one remains as a fallback. v2.0 is the last release that works against Sql Server.

Concepts

There are several concepts defined in ImageStore. Reading these docs will help you to understand the system.

Concept	Description
Database	A Sql Server 2017 database to save all records and settings.
Folder	The root directory of your image library.
Extension	Extension record for each kind of files.
File	File record for each file.
Same File	Exactly same files detected by Sha1 hashing.
Similar File	Similar images detected by pHash algorithm.
Thumbprint Cache	Cache for image thumbprints used in Similar File UI.
Difference Degree	The difference between two image files.

Cmdlets

See Cmdlets.

Entity Types

These types of entities will be used while operating with cmdlets of ImageStore.

Type	Description
ImageStoreFolder	Represents a folder for storing image files.
ImageStoreIgnoredDirectory	Represents an exclusion a directory from a folder.
ImageStoreExtension	Represents an extension, a kind of file.
ImageStoreFile	Represents a file stored in a folder.
ImageStoreSameFile	Represents a record that a file detected to be the same as at least one other file.
ImageStoreSimilarFile	Represents a similar relationship between two image files.

Other Types

These types will be used while operating with cmdlets of ImageStore.

Type	Class	Description
StringPropertyComparingModes	enum	The way to use the string provided as search condition.

Walkthrough

A walkthrough of use this product.