File Associations - ImageGlass

ImageGlass can be registered as the default photo viewer for image file formats using command-line tools. This is useful for automated installations, system configuration, and user preferences management.

set-default-viewer

Syntax

igcmd.exe set-default-viewer [extensions] [--per-machine] [--ui]

Parameters

extensions

string

default:"all supported formats"

Semicolon-separated list of file extensions to registerFormat: .ext1;.ext2;.ext3Examples:

.jpg;.png;.gif - Common web formats
.jpg;.jpeg;.png;.bmp - Basic image formats
.webp;.avif;.heic - Modern formats

If omitted, all supported image formats are registered.

--per-machine

flag

Apply registration system-wide for all usersRequires: Administrator privilegesWithout this flag: Registration applies to current user only

--ui

flag

Show confirmation dialog on successful registrationDisplays a user-friendly message with registration details

Exit Codes

Code	Description
`0`	Registration successful
`1`	Administrator privileges required
`2`	Error during registration

Examples

Register All Supported Formats

igcmd.exe set-default-viewer

Registers ImageGlass as default viewer for all supported image formats (PNG, JPG, GIF, WebP, BMP, TIFF, SVG, ICO, and more) for the current user.

Register Specific Formats

igcmd.exe set-default-viewer ".jpg;.png;.gif"

Registers only common web image formats.

System-Wide Registration

igcmd.exe set-default-viewer --per-machine

Registers for all users on the system. Requires administrator privileges.

With User Confirmation

igcmd.exe set-default-viewer ".jpg;.png" --ui

Shows a confirmation dialog after successful registration.

Complete Registration with UI

igcmd.exe set-default-viewer ".jpg;.jpeg;.png;.gif;.bmp;.webp" --per-machine --ui

Registers common formats system-wide and shows confirmation.

Common Extension Sets

Basic Image Formats

igcmd.exe set-default-viewer ".jpg;.jpeg;.png;.gif;.bmp"

Legacy and widely-supported formats.

Modern Web Formats

igcmd.exe set-default-viewer ".webp;.avif;.svg"

Next-generation web image formats.

RAW Photography Formats

igcmd.exe set-default-viewer ".cr2;.nef;.arw;.dng;.raw"

Common camera RAW formats (requires codec support).

All Common Formats

igcmd.exe set-default-viewer ".jpg;.jpeg;.png;.gif;.bmp;.tiff;.tif;.webp;.ico;.svg"

Advanced Usage

Installation Script

@echo off
echo Installing ImageGlass as default photo viewer...

rem Install for current user first
igcmd.exe set-default-viewer --ui

if %ERRORLEVEL% EQU 0 (
    echo Successfully registered for current user
) else (
    echo Failed to register
    exit /b 1
)

System Deployment Script

@echo off
rem Run with administrator privileges

echo Registering ImageGlass system-wide...
igcmd.exe set-default-viewer --per-machine

if %ERRORLEVEL% EQU 1 (
    echo Administrator privileges required
    echo Please run as administrator
    exit /b 1
)

if %ERRORLEVEL% EQU 0 (
    echo Registration successful
) else (
    echo Registration failed
    exit /b 2
)

PowerShell Registration

# Check for admin privileges
$isAdmin = ([Security.Principal.WindowsPrincipal] [Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)

if ($isAdmin) {
    Write-Host "Registering system-wide..."
    & igcmd.exe set-default-viewer --per-machine --ui
} else {
    Write-Host "Registering for current user..."
    & igcmd.exe set-default-viewer --ui
}

if ($LASTEXITCODE -eq 0) {
    Write-Host "Registration successful" -ForegroundColor Green
} else {
    Write-Host "Registration failed" -ForegroundColor Red
    exit $LASTEXITCODE
}

remove-default-viewer

Unregister ImageGlass as the default photo viewer for specified file extensions.

Syntax

igcmd.exe remove-default-viewer [extensions] [--per-machine] [--ui]

Parameters

extensions

string

default:"all registered formats"

Semicolon-separated list of file extensions to unregisterFormat: .ext1;.ext2;.ext3If omitted, all registered formats are unregistered.

--per-machine

flag

Remove system-wide registration for all usersRequires: Administrator privileges

--ui

flag

Show confirmation dialog on successful removal

Exit Codes

Code	Description
`0`	Unregistration successful
`1`	Administrator privileges required
`2`	Error during unregistration

Examples

Remove All Associations

igcmd.exe remove-default-viewer

Removes ImageGlass as default viewer for all registered formats.

Remove Specific Formats

igcmd.exe remove-default-viewer ".jpg;.png"

Removes only specified format associations.

System-Wide Removal

igcmd.exe remove-default-viewer --per-machine

Removes system-wide associations. Requires administrator privileges.

With Confirmation Dialog

igcmd.exe remove-default-viewer --ui

Shows confirmation after removal.

Advanced Usage

Uninstall Script

@echo off
echo Removing ImageGlass file associations...

igcmd.exe remove-default-viewer --ui

if %ERRORLEVEL% EQU 0 (
    echo Associations removed successfully
) else (
    echo Failed to remove associations
)

Clean Removal Script

@echo off
rem Remove user and system associations

echo Removing user associations...
igcmd.exe remove-default-viewer

if %ERRORLEVEL% EQU 0 (
    echo User associations removed
)

echo Removing system associations...
igcmd.exe remove-default-viewer --per-machine

if %ERRORLEVEL% EQU 1 (
    echo System removal requires administrator privileges
) else if %ERRORLEVEL% EQU 0 (
    echo System associations removed
)

PowerShell Removal

Write-Host "Removing ImageGlass associations..."

& igcmd.exe remove-default-viewer --ui

if ($LASTEXITCODE -eq 0) {
    Write-Host "Successfully removed associations" -ForegroundColor Green
} elseif ($LASTEXITCODE -eq 1) {
    Write-Host "Administrator privileges required" -ForegroundColor Yellow
} else {
    Write-Host "Failed to remove associations" -ForegroundColor Red
}

Understanding File Associations

Per-User vs Per-Machine

Per-User Registration (Default)

igcmd.exe set-default-viewer

Applies to current user only
No administrator privileges required
Stored in HKEY_CURRENT_USER registry
Does not affect other users
Preferred for personal installations

Per-Machine Registration

igcmd.exe set-default-viewer --per-machine

Applies to all users on the system
Requires administrator privileges
Stored in HKEY_LOCAL_MACHINE registry
Affects all user accounts
Preferred for enterprise deployments

Supported Image Formats

When registering without specifying extensions, ImageGlass registers for all supported formats:

Raster: JPG, PNG, GIF, BMP, TIFF, WebP, AVIF, HEIC, HEIF
Vector: SVG
Icons: ICO, CUR
RAW: CR2, NEF, ARW, DNG, RAF, ORF (with codecs)
Other: TGA, PCX, PSD (preview)

Windows Default Apps

After registration:

ImageGlass appears in Windows “Default apps” settings
Users can still manually change associations in Settings
Registration creates the necessary registry entries
Does not override user’s explicit manual choices

Deployment Scenarios

Silent Installation

@echo off
rem Silent installation with file associations

msiexec /i ImageGlass.msi /quiet
igcmd.exe set-default-viewer --per-machine
exit /b %ERRORLEVEL%

Interactive Installation

@echo off
echo Installing ImageGlass...
msiexec /i ImageGlass.msi /qb

echo.
echo Would you like to set ImageGlass as default photo viewer? (Y/N)
set /p choice="Your choice: "

if /i "%choice%"=="Y" (
    igcmd.exe set-default-viewer --ui
)

Enterprise Group Policy Script

@echo off
rem GPO startup script for IT deployment

rem Check if ImageGlass is installed
if not exist "C:\Program Files\ImageGlass\igcmd.exe" (
    echo ImageGlass not installed
    exit /b 1
)

rem Register system-wide
"C:\Program Files\ImageGlass\igcmd.exe" set-default-viewer --per-machine

if %ERRORLEVEL% EQU 0 (
    echo ImageGlass registered successfully
) else (
    echo Failed to register ImageGlass
    exit /b 1
)

PowerShell Deployment

# Enterprise deployment script

function Install-ImageGlassAssociations {
    param(
        [string]$Scope = "CurrentUser"
    )
    
    $igcmdPath = "C:\Program Files\ImageGlass\igcmd.exe"
    
    if (-not (Test-Path $igcmdPath)) {
        Write-Error "ImageGlass not found at $igcmdPath"
        return $false
    }
    
    $arguments = @("set-default-viewer")
    
    if ($Scope -eq "AllUsers") {
        $arguments += "--per-machine"
    }
    
    $result = Start-Process -FilePath $igcmdPath -ArgumentList $arguments -Wait -PassThru -NoNewWindow
    
    return ($result.ExitCode -eq 0)
}

# Usage
if (Install-ImageGlassAssociations -Scope "AllUsers") {
    Write-Host "Successfully registered ImageGlass" -ForegroundColor Green
} else {
    Write-Host "Failed to register ImageGlass" -ForegroundColor Red
}

Error Handling

Comprehensive Error Handling

@echo off
setlocal

set "extensions=.jpg;.png;.gif"

echo Registering ImageGlass for: %extensions%
igcmd.exe set-default-viewer "%extensions%" --ui

if %ERRORLEVEL% EQU 0 (
    echo Registration successful
    exit /b 0
)

if %ERRORLEVEL% EQU 1 (
    echo.
    echo Administrator privileges required.
    echo Please run this script as administrator.
    echo.
    pause
    exit /b 1
)

if %ERRORLEVEL% EQU 2 (
    echo.
    echo An error occurred during registration.
    echo Please check that ImageGlass is properly installed.
    echo.
    pause
    exit /b 2
)

echo Unknown error
exit /b %ERRORLEVEL%

PowerShell Error Handling

try {
    $extensions = ".jpg;.png;.gif;.webp"
    
    Write-Host "Registering file associations: $extensions"
    
    $process = Start-Process -FilePath "igcmd.exe" `
        -ArgumentList "set-default-viewer", $extensions, "--ui" `
        -Wait -PassThru -NoNewWindow
    
    switch ($process.ExitCode) {
        0 {
            Write-Host "Registration successful" -ForegroundColor Green
        }
        1 {
            Write-Warning "Administrator privileges required"
            
            # Prompt to elevate
            $elevated = Start-Process -FilePath "igcmd.exe" `
                -ArgumentList "set-default-viewer", $extensions, "--ui", "--per-machine" `
                -Verb RunAs -Wait -PassThru
            
            if ($elevated.ExitCode -eq 0) {
                Write-Host "Registration successful (elevated)" -ForegroundColor Green
            }
        }
        2 {
            Write-Error "Registration failed. Check ImageGlass installation."
        }
        default {
            Write-Error "Unknown error occurred (exit code: $($process.ExitCode))"
        }
    }
} catch {
    Write-Error "Exception occurred: $_"
}

Testing Associations

Verify Registration

# Check if ImageGlass is registered for a specific extension
function Test-ImageGlassAssociation {
    param([string]$Extension)
    
    $key = "HKCU:\Software\Classes\$Extension"
    
    if (Test-Path $key) {
        $value = Get-ItemProperty -Path $key -Name "(Default)" -ErrorAction SilentlyContinue
        
        if ($value -and $value."(Default)" -match "ImageGlass") {
            Write-Host "$Extension is associated with ImageGlass" -ForegroundColor Green
            return $true
        }
    }
    
    Write-Host "$Extension is NOT associated with ImageGlass" -ForegroundColor Red
    return $false
}

# Test common formats
@(".jpg", ".png", ".gif", ".webp") | ForEach-Object {
    Test-ImageGlassAssociation $_
}

Command Line

​set-default-viewer

​Syntax

​Parameters

​Exit Codes

​Examples

​Register All Supported Formats

​Register Specific Formats

​System-Wide Registration

​With User Confirmation

​Complete Registration with UI

​Common Extension Sets

​Basic Image Formats

​Modern Web Formats

​RAW Photography Formats

​All Common Formats

​Advanced Usage

​Installation Script

​System Deployment Script

​PowerShell Registration

​remove-default-viewer

​Syntax

​Parameters

​Exit Codes

​Examples

​Remove All Associations

​Remove Specific Formats

​System-Wide Removal

​With Confirmation Dialog

​Advanced Usage

​Uninstall Script

​Clean Removal Script

​PowerShell Removal

​Understanding File Associations

​Per-User vs Per-Machine

​Per-User Registration (Default)

​Per-Machine Registration

​Supported Image Formats

​Windows Default Apps

​Deployment Scenarios

​Silent Installation

​Interactive Installation

​Enterprise Group Policy Script

​PowerShell Deployment

​Error Handling

​Comprehensive Error Handling

​PowerShell Error Handling

​Testing Associations

​Verify Registration

​See Also

Build docs developers (and LLMs) love

set-default-viewer

Syntax

Parameters

Exit Codes

Examples

Register All Supported Formats

Register Specific Formats

System-Wide Registration

With User Confirmation

Complete Registration with UI

Common Extension Sets

Basic Image Formats

Modern Web Formats

RAW Photography Formats

All Common Formats

Advanced Usage

Installation Script

System Deployment Script

PowerShell Registration

remove-default-viewer

Syntax

Parameters

Exit Codes

Examples

Remove All Associations

Remove Specific Formats

System-Wide Removal

With Confirmation Dialog

Advanced Usage

Uninstall Script

Clean Removal Script

PowerShell Removal

Understanding File Associations

Per-User vs Per-Machine

Per-User Registration (Default)

Per-Machine Registration

Supported Image Formats

Windows Default Apps

Deployment Scenarios

Silent Installation

Interactive Installation

Enterprise Group Policy Script

PowerShell Deployment

Error Handling

Comprehensive Error Handling

PowerShell Error Handling

Testing Associations

Verify Registration

See Also