Art Meets Fusion Technology: The Skull Experiment

10 minutes reading time for Linux systems – 15 minutes all operating systems – 1 minute video

Don’t worry – no lead suits or Geiger counters required. We’re not dealing with cold fusion or Soviet-era nuclear tech here (tempting as that sounds). This kind of Fusion is much friendlier – though still deliciously technical. We’re talking about photo merging, using Enfuse, driven by a script that’s been through more versions than I dare admit.

🟡 FUSION TECHNOLOGY
Powered by radioactive imagination – not by actual uranium.

# Welcome to the Fusion Reactor v8# Initiating photo merging protocol...enfuse -o result.tif --exposure-weight=1 --saturation-weight=0.2 --contrast-weight=0.3 input1.tif input2.tif input3.tif# Fusion complete. No meltdown detected...

I call it version eight… but truth be told, it’s probably closer to version fifty. Some ran on Windows, others thrived on Linux. Names have ranged from Fusion Reactors to Fusion Generators. No Photo Shop, just cold terminal code – because let’s face it, who wouldn’t want to run a photo reactor?

And now? You’re invited to join in. Whether you’re just dipping a toe into scripting or already automating your coffee machine with bash, this is a great place to start. Simple, fast, and just technical enough to be fun. Welcome to the gentler side of Fusion Technology.

Note : To work with scripts or batch files, it’s helpful to have a basic understanding of using a terminal (Linux) or command prompt (Windows), navigating files and folders, recognizing file extensions (.sh for Linux scripts, .bat for Windows), and understanding file permissions. Basic knowledge of using a text editor to create and edit simple files is also important. These skills will help you execute scripts effectively and safely – Also, all scripts mentioned here for Windows are untested, as are the suggested tools for macOS or iOS—simply because I no longer work on Windows and don’t own any Windows or Apple computers. Caution is advised when testing these scripts and tools. The Linux FusionUtility script has been fully tested and is working on Ubuntu 20.04–24.04, provided that Enfuse or Hugin is properly installed.

Why I created the Fusion Script

Well, I’ve been using scripts almost as long as I’ve been working with computers, especially professionally where they were necessary, but they’ve also been very useful for hobby purposes. In the past, I used them on Windows, but nowadays I work with Linux. I’ve used a script to run Enfuse on both systems, and there have been many versions over time. This year, I created a new script called FusionUtility version 8 (of this year), and at the end, I also discuss a Windows version.

HDR photography often requires careful balance. I want to push the boundaries of dynamic range without overdoing it. My workflow helps achieve that by using a fusion script that combines the best of both worlds: an extreme HDR effect for vibrancy and detail, paired with a process that smooths out any excess. The fusion script plays a crucial role in merging a normal and a very different HDR version into one, resulting in a balanced final image that retains the strength of the HDR without crossing into the territory of artificiality or noise.

How the Fusion Script Works

Creating the Base Image in RawTherapee
I begin by processing a RAW image in RawTherapee, carefully adjusting exposure, shadows, highlights, and contrast to create a well-balanced TIFF. This TIFF will serve as my baseline image. It’s important to get this right as it helps maintain natural color balance and detail.

Enhancing the Image in Luminance HDR
Next, I take the TIFF file into Luminance HDR, where I apply stronger settings that create a more extreme HDR. The idea here is to push the image’s dynamic range further while retaining the details in both the shadows and highlights. The result is a much more dramatic (read ugly) effect, emphasizing the broad spectrum of light in the image.

Using the Fusion Script
The final step is where the magic happens: I run both the original TIFF from RawTherapee and the extreme HDR TIFF from Luminance HDR through the fusion script. The script automatically merges the two images, taking the base image’s balance and applying the intense HDR details from the second image. This fusion process smooths out the extremes, ensuring that the image has a strong dynamic range but doesn’t suffer from unnatural halos, excessive contrast, or noise. By automating the process, it saves me a lot of time while maintaining full control over the result.

By using this method, I get the best of both worlds: the natural look of the initial image combined with the extreme HDR effect that I can fine-tune further for artistic impact in RawTherapee.

HDR compared with Fusion :

Normal compared with Fusion :

Note: At this point, I’d like to emphasize that Enfuse, and thus the script, can be used for much more than just merging HDR images. The program and script are designed to fuse images, which opens up many creative possibilities!

HDR Fusion with Enfuse on Linux – Made Simple

If you’re working on Linux and want a quick, effective way to blend multiple images into one balanced HDR, Enfuse is your friend. This article introduces a Bash-based utility script that simplifies the process, complete with a menu and logging system. But even without the script, you can use Enfuse with a simple command from the terminal.

Requirements

To use the script or run Enfuse manually, make sure the following are installed:

• enfuse (usually included with the Hugin suite)
• bash (standard on most Linux distributions)
• Basic terminal access and permission to execute scripts

You can install Enfuse via your package manager. For example, on Debian/Ubuntu:

sudo apt install hugin

This also installs Enfuse and related tools.

Quick Start – The Simple Way

Place your aligned input images (e.g., multiple TIFFs) in a folder, open a terminal in that folder, and type:

enfuse --exposure-weight=1 --saturation-weight=1 --contrast-weight=1 --hard-mask -o result.tif *.tif

This will merge all .tif files in the folder into a single image called result.tif, using default weight parameters and a hard mask.

If you’d like a friendlier interface and to keep track of your settings, try the FusionUtility script provided below.

The code used for FusionUtility v8
Copy the code and paste it into a text editor, then save it—for example—as FusionUtility.sh.
You can either make it executable via Properties → Permissions → Allow executing as program,
or run the following command:

chmod +x FusionUtility.sh

Then launch it in the Terminal with:

bash FusionUtility.sh

#!/bin/bashlogfile="./lastfusion.txt"lastsettings=".lastsettings"print_header() {  clear  echo -e "\n╔══════════════════════════════════════════════╗"  printf "║ %-44s ║\n" "$1"  echo "╚══════════════════════════════════════════════╝"}validate_numeric() {  [[ "$1" =~ ^[0-9.]+$ ]] || { echo "Invalid number: $1"; exit 1; }}save_last_settings() {  echo "$1" > "$lastsettings"  echo "$2" >> "$lastsettings"  echo "$3" >> "$lastsettings"  echo "$4" >> "$lastsettings"  echo "$5" >> "$lastsettings"  echo "$6" >> "$lastsettings"}load_last_settings() {  IFS=$'\n' read -d '' -r last_dir last_ext last_exposure last_saturation last_contrast hmasklog < "$lastsettings"  hardmask=$( [[ "$hmasklog" == "YES" ]] && echo "--hard-mask" )}print_header "ENFUSE FUSION TOOL - MAIN MENU"echo "║  1. Quick Fusion (default weights)   ║"echo "║  2. Custom Fusion (interactive input)║"echo "║  3. Repeat Last Fusion   ║"echo "║  Q. Quit ║"echo "╚══════════════════════════════════════════════╝"read -p "Choose an option [1, 2, 3, Q]: " runoptioncase "$runoption" in  "1")print_header "QUICK FUSION – DEFAULT SETTINGS"read -p "Image Path (no trailing slash): " variable1[[ -z "$variable1" || ! -d "$variable1" ]] && { echo "Invalid path."; exit 1; }read -p "Image Extension (jpg, tif, etc.): " ext1timestamp=$(date +"%Y%m%d_%H%M%S")outputfile="$variable1/output_$timestamp.$ext1"echo "Starting fusion with default weights..."enfuse --exposure-weight=1 --saturation-weight=1 --contrast-weight=1 --hard-mask --output="$outputfile" "$variable1"/*."$ext1"echo "Output written to $outputfile"echo -e "\n[QUICK FUSION - $timestamp]" >> "$logfile"echo "Source: $variable1/*.${ext1}" >> "$logfile"echo "Output: $outputfile" >> "$logfile"echo "Weights: exposure=1, saturation=1, contrast=1" >> "$logfile"echo "Hard Mask: YES" >> "$logfile"save_last_settings "$variable1" "$ext1" 1 1 1 YESread -p "View output image? (y/n): " viewimg[[ "$viewimg" =~ ^[Yy]$ ]] && xdg-open "$outputfile" >/dev/null 2>&1 &;;  "2")print_header "CUSTOM FUSION – YOUR SETTINGS"read -p "Image Path (no trailing slash): " variable1[[ -z "$variable1" || ! -d "$variable1" ]] && { echo "Invalid path."; exit 1; }read -p "Image Extension (jpg, tif, etc.): " ext1read -p "Exposure weight (e.g., 1): " exposure; validate_numeric "$exposure"read -p "Saturation weight (e.g., 0.2): " saturation; validate_numeric "$saturation"read -p "Contrast weight (e.g., 0.3): " contrast; validate_numeric "$contrast"read -p "Use hard mask? (y/n): " hardmaskchoicehardmask=""; hmasklog="NO"[[ "$hardmaskchoice" =~ ^[Yy]$ ]] && { hardmask="--hard-mask"; hmasklog="YES"; }timestamp=$(date +"%Y%m%d_%H%M%S")outputfile="$variable1/output_$timestamp.$ext1"echo "Starting custom fusion..."enfuse --exposure-weight="$exposure" --saturation-weight="$saturation" --contrast-weight="$contrast" $hardmask --output="$outputfile" "$variable1"/*."$ext1"echo "Output written to $outputfile"echo -e "\n[CUSTOM FUSION - $timestamp]" >> "$logfile"echo "Source: $variable1/*.${ext1}" >> "$logfile"echo "Output: $outputfile" >> "$logfile"echo "Weights: exposure=$exposure, saturation=$saturation, contrast=$contrast" >> "$logfile"echo "Hard Mask: $hmasklog" >> "$logfile"save_last_settings "$variable1" "$ext1" "$exposure" "$saturation" "$contrast" "$hmasklog"read -p "View output image? (y/n): " viewimg[[ "$viewimg" =~ ^[Yy]$ ]] && xdg-open "$outputfile" >/dev/null 2>&1 &;;  "3")print_header "REPEAT LAST FUSION"[[ ! -f "$lastsettings" ]] && { echo "No previous fusion found."; exit 1; }load_last_settingsecho "Last settings:"echo "Source folder: $last_dir"echo "Extension: $last_ext"echo "Weights: exposure=$last_exposure, saturation=$last_saturation, contrast=$last_contrast"echo "Hard Mask: $hmasklog"timestamp=$(date +"%Y%m%d_%H%M%S")outputfile="$last_dir/output_$timestamp.$last_ext"echo "Starting repeat fusion..."enfuse --exposure-weight="$last_exposure" --saturation-weight="$last_saturation" --contrast-weight="$last_contrast" $hardmask --output="$outputfile" "$last_dir"/*."$last_ext"echo "Output written to $outputfile"echo -e "\n[REPEATED FUSION - $timestamp]" >> "$logfile"echo "Source: $last_dir/*.${last_ext}" >> "$logfile"echo "Output: $outputfile" >> "$logfile"echo "Weights: exposure=$last_exposure, saturation=$last_saturation, contrast=$last_contrast" >> "$logfile"echo "Hard Mask: $hmasklog" >> "$logfile"read -p "View output image? (y/n): " viewimg[[ "$viewimg" =~ ^[Yy]$ ]] && xdg-open "$outputfile" >/dev/null 2>&1 &;;  "Q"|"q")echo "Bye!"exit 0;;  *)echo "Invalid option. Exiting."exit 1;;esac

In Action:

HDR Fusion with Enfuse on Windows – Made Simple

If you’re working on Windows and want a simple way to combine multiple images into a balanced HDR, Enfuse is a great choice. This article introduces a .bat batch script that streamlines the process, providing a basic interface and saving your settings for easy access. Alternatively, you can use Enfuse directly with simple commands in the Command Prompt.

Requirements

Before using the script or running Enfuse manually, make sure you have the following installed:

• Enfuse (available with Hugin or as a separate download)
• A Command Prompt or Windows PowerShell
• bash (available through tools like Git Bash or WSL for Windows 10/11)

To install Enfuse, you can download it as part of the Hugin suite from the official website. Alternatively, you can extract the executable and use it directly.

Even simpler, some smartasses might think — but hey, we’re talking command line, get it? That said, yes… there are simpler tools like… EnfuseGUI

Quick Start – The Simple Way

Place your aligned input images (e.g., multiple TIFFs) in a folder. Then, open the Command Prompt in that folder, and type the following command:

enfuse --exposure-weight=1 --saturation-weight=1 --contrast-weight=1 --hard-mask -o result.tif *.tif

This command will merge all .tif files in the folder into a single image called result.tif, using the default weight parameters and a hard mask.

For a more user-friendly experience with settings saved between uses, try the provided .bat script below – the process is roughly the same as in Linux: copy the text, paste it into a text editor, and save it as, for example, ‘fusion_tool.bat’.

@echo offsetlocal ENABLEDELAYEDEXPANSION:main_menuclsecho.echo ╔══════════════════════════════════════════════╗echo ║ENFUSE FUSION TOOL - MAIN MENU║echo ╠══════════════════════════════════════════════╣echo ║  1. Quick Fusion (default weights)   ║echo ║  2. Custom Fusion (interactive input)║echo ║  3. Repeat Last Fusion   ║echo ║  Q. Quit ║echo ╚══════════════════════════════════════════════╝set /p runoption=Choose an option [1, 2, 3, Q]: if /i "%runoption%"=="1" goto quickif /i "%runoption%"=="2" goto customif /i "%runoption%"=="3" goto repeatif /i "%runoption%"=="q" exitecho Invalid option.pausegoto main_menu:quickclsecho --- QUICK FUSION ---set /p folder=Image folder (no trailing backslash): if not exist "%folder%" (echo Invalid path.pausegoto main_menu)set /p ext=Image extension (jpg, tif, etc.): set timestamp=%date:~6,4%%date:~3,2%%date:~0,2%_%time:~0,2%%time:~3,2%%time:~6,2%set output=%folder%\output_%timestamp%.%ext%echo Starting fusion with default weights...enfuse --exposure-weight=1 --saturation-weight=1 --contrast-weight=1 --hard-mask --output="%output%" "%folder%\*.%ext%"echo Output written to: %output%(echo [QUICK FUSION - %timestamp%]echo Source: %folder%\*.%ext%echo Output: %output%echo Weights: exposure=1, saturation=1, contrast=1echo Hard Mask: YES) > lastfusion.txtecho %folder%>%~dp0.lastsettingsecho %ext%>>%~dp0.lastsettingsecho 1>>%~dp0.lastsettingsecho 1>>%~dp0.lastsettingsecho 1>>%~dp0.lastsettingsecho YES>>%~dp0.lastsettingsset /p viewimg=View output image? (y/n): if /i "%viewimg%"=="y" start "" "%output%"goto end:customclsecho --- CUSTOM FUSION ---set /p folder=Image folder (no trailing backslash): if not exist "%folder%" (echo Invalid path.pausegoto main_menu)set /p ext=Image extension (jpg, tif, etc.): set /p exp=Exposure weight (e.g., 1): set /p sat=Saturation weight (e.g., 0.2): set /p con=Contrast weight (e.g., 0.3): set /p hmask=Use hard mask? (y/n): set hardmask=set hmasklog=NOif /i "%hmask%"=="y" (set hardmask=--hard-maskset hmasklog=YES)set timestamp=%date:~6,4%%date:~3,2%%date:~0,2%_%time:~0,2%%time:~3,2%%time:~6,2%set output=%folder%\output_%timestamp%.%ext%echo Starting custom fusion...enfuse --exposure-weight=%exp% --saturation-weight=%sat% --contrast-weight=%con% %hardmask% --output="%output%" "%folder%\*.%ext%"echo Output written to: %output%(echo [CUSTOM FUSION - %timestamp%]echo Source: %folder%\*.%ext%echo Output: %output%echo Weights: exposure=%exp%, saturation=%sat%, contrast=%con%echo Hard Mask: %hmasklog%) > lastfusion.txtecho %folder%>%~dp0.lastsettingsecho %ext%>>%~dp0.lastsettingsecho %exp%>>%~dp0.lastsettingsecho %sat%>>%~dp0.lastsettingsecho %con%>>%~dp0.lastsettingsecho %hmasklog%>>%~dp0.lastsettingsset /p viewimg=View output image? (y/n): if /i "%viewimg%"=="y" start "" "%output%"goto end:repeatclsecho --- REPEAT LAST FUSION ---if not exist "%~dp0.lastsettings" (echo No previous settings found.pausegoto main_menu)set /p folder=<"%~dp0.lastsettings"for /f "tokens=1" %%a in ('more +1 "%~dp0.lastsettings"') do set ext=%%a & goto next1:next1for /f "tokens=1" %%a in ('more +2 "%~dp0.lastsettings"') do set exp=%%a & goto next2:next2for /f "tokens=1" %%a in ('more +3 "%~dp0.lastsettings"') do set sat=%%a & goto next3:next3for /f "tokens=1" %%a in ('more +4 "%~dp0.lastsettings"') do set con=%%a & goto next4:next4for /f "tokens=1" %%a in ('more +5 "%~dp0.lastsettings"') do set hmasklog=%%aset hardmask=if /i "%hmasklog%"=="YES" set hardmask=--hard-maskset timestamp=%date:~6,4%%date:~3,2%%date:~0,2%_%time:~0,2%%time:~3,2%%time:~6,2%set output=%folder%\output_%timestamp%.%ext%echo Repeating fusion...enfuse --exposure-weight=%exp% --saturation-weight=%sat% --contrast-weight=%con% %hardmask% --output="%output%" "%folder%\*.%ext%"echo Output written to: %output%(echo [REPEATED FUSION - %timestamp%]echo Source: %folder%\*.%ext%echo Output: %output%echo Weights: exposure=%exp%, saturation=%sat%, contrast=%con%echo Hard Mask: %hmasklog%) >> lastfusion.txtset /p viewimg=View output image? (y/n): if /i "%viewimg%"=="y" start "" "%output%"goto end:endecho Done.pauseexit /b

And then we have Apple.

Here are a few apps for macOS and iOS that are more similar to Enfuse for merging images, without being full-fledged HDR editors:

For macOS:

1. Hugin
   • Hugin is an open-source tool that can be used for merging images, especially for panoramas, but it also allows you to combine multiple images with varying exposure settings. You can use it in a similar way to Enfuse, offering a command-line option for advanced users, along with a graphical interface.
   • Website: Hugin
2. ImageMagick
   • ImageMagick is a command-line tool that allows for the merging of images, including exposure blending. While it’s not as specialized for HDR as Enfuse, it can be used for many image manipulation tasks, including combining multiple images into one.
   • Website: ImageMagick
3. Enfuse (via Terminal)
   • As mentioned before, Enfuse can be used on macOS via the terminal. If you’re comfortable with command-line tools, you can install Enfuse using Homebrew and use it to merge images efficiently.
   • Homebrew installation: brew install enfuse
4. Photomatix Pro
   • Although Photomatix Pro is mainly used for HDR, it also allows you to merge images based on exposure, which is essentially the same process that Enfuse uses. It’s a more user-friendly option for those looking to get quick results without diving too deep into the command line.
   • Website: Photomatix Pro

For iOS:

1. ProCamera
   • ProCamera is a photography app that lets you capture multiple exposures manually and merge them together to create a final image. It’s designed for advanced users who want control over their image capturing process, and although not a direct equivalent of Enfuse, it offers manual exposure adjustments that can be combined for creative purposes.
   • App Store: ProCamera
2. iHDR
   • iHDR is an iOS app specifically designed for merging images with different exposures, much like Enfuse. It’s a simple and intuitive app for HDR processing on the go, but its core function revolves around merging multiple photos into a final image with enhanced dynamic range.
   • App Store: iHDR
3. AutoStitch Panorama
   • AutoStitch is primarily a panorama app, but it can also be used to merge images with different exposures to create a single, cohesive final image. While it’s not as feature-rich as Enfuse, it’s useful for simple image merging tasks and works well on iOS.
   • App Store: AutoStitch Panorama
4. Fusion HDR Camera
   • Fusion HDR Camera is an iOS app that allows you to merge multiple photos taken at different exposures, similar to how Enfuse works. The app is specifically designed to create HDR images by merging different exposures and it offers a streamlined process for mobile users.
   • App Store: Fusion HDR Camera

Summary:

For macOS, tools like Hugin, ImageMagick, and Enfuse itself are your best bets for merging images. These apps and tools allow you to blend multiple exposures and create a single image with greater dynamic range or creative effects, similar to Enfuse. On iOS, apps like ProCamera, iHDR, and Fusion HDR Camera are simple yet effective ways to merge images directly on your device.

This article was written by Marc R.
While I primarily speak Dutch and have some knowledge of English and a little French, ChatGPT helps ensure my writing is grammatically correct. I often mix Dutch and English in my drafts, and ChatGPT steps in to translate and correct.