ChromIQ

ChromIQ is a macOS desktop application for creating custom ICC profiles for RGB inkjet printers using ArgyllCMS. It provides a guided, five-step workflow that takes you from generating and printing a test chart through measuring it, building a ready-to-use ICC profile, and verifying its quality — without needing to touch the command line.

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Download

Pre-built DMGs are attached to each GitHub Release:

Build	Runs on
ChromIQ-macOS-universal.dmg	Apple Silicon and Intel (recommended)
ChromIQ-macOS-arm64.dmg	Apple Silicon only

Open the DMG, drag ChromIQ to Applications, eject, then launch. First launch: right-click → Open to bypass Gatekeeper (the app is ad-hoc signed, not notarized). ArgyllCMS must be installed separately — see Requirements.

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Screenshots

Step 1a — Create Chart (guided)	Step 1b — Create Chart (manual)

Step 2 — Print Chart	Step 3 — Measure Chart

Step 4 — Build Profile	Step 5 — Check & Refine

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Features

Guided Workflow

ChromIQ walks you through five steps of RGB printer profiling:

1. Create Chart — generates a test chart using targen and printtarg, with automatic patch count calculation for your instrument/paper combination
2. Print Chart — sends the chart TIFF directly to your printer via CUPS with configurable print options
3. Measure Chart — drives your spectrophotometer with chartread to measure the printed patches
4. Build Profile — runs colprof to generate a finished ICC profile
5. Check & Refine — evaluates the finished profile with profcheck, shows per-patch ΔE statistics, and guides you through a targeted re-measurement to improve accuracy

Guided and Manual Modes

• Guided mode (Step 1): Select instrument, paper size, and number of pages — ChromIQ looks up the optimal patch count from an empirical database and sets sensible defaults automatically.
• Manual mode (Step 1): Full access to all targen and printtarg flags for advanced users.

Instrument Support

Code	Instrument
i1	X-Rite i1Pro / i1Pro 2 / i1Pro 3
p3	X-Rite i1Pro 3 Plus
CM	X-Rite ColorMunki / i1Studio / ColorChecker Studio
SS	X-Rite SpectroScan (flatbed XY)

Paper Size Support

A4, A4 Landscape, A3, A3 Landscape, A2, US Letter, Letter Landscape, Legal, Tabloid (11×17)

Key Capabilities

• Empirical patch capacity database (measured with Argyll 3.5.0) for instant lookup without binary search
• Separate patch counts for charts with and without the left clip border (-L flag)
• Double-density mode for ColorMunki/i1Studio with measuring rig (-h flag)
• Live TIFF preview of the generated test chart
• Direct TIFF printing via CUPS (no PostScript conversion, no ColorSync interference)
• Full colprof option set: illuminant, observer, FWA compensation, gamut mapping source profiles, rendering intent overrides
• Automatic file naming based on printer, paper, paper type, instrument, and timestamp
• Settings persist between sessions via QSettings
• Built-in ArgyllCMS binary tester and direct download link detection for your platform

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Requirements

System

• macOS 12 Ventura or later (Apple Silicon and Intel supported)
• ArgyllCMS 3.5.0 — binaries must be installed at /Applications/Argyll/bin (configurable in Preferences)

To run from source

• Python 3.12 or later

Python dependencies

PyQt6 >= 6.11.0
Pillow >= 10.0.0
PyYAML >= 6.0

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Installation

Pre-built app (recommended)

Download the latest DMG from the Releases page, open it, drag ChromIQ to Applications, and launch. No Python or build tools required.

From source

git clone https://github.com/itsab1989/ChromIQ.git
cd ChromIQ
python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
python main.py

Build a standalone .app from source

source .venv/bin/activate
pip install pyinstaller
pyinstaller ChromIQ.spec
# Result: dist/ChromIQ.app

Copy dist/ChromIQ.app to /Applications and launch like any other macOS app. ArgyllCMS binaries are not bundled — install them separately and configure the path in Preferences.

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Usage

First-time setup

1. Install ArgyllCMS and note the path to its bin folder (default: /Applications/Argyll/bin)
2. Open ChromIQ → ChromIQ ▸ Preferences (or ⌘,) and verify the binary path
3. Click Test binaries to confirm targen, printtarg, chartread, and colprof are found

Step 1 — Create Chart

• Choose Guided or Manual mode
• In Guided mode: select your instrument and paper size, set the number of pages, and ChromIQ calculates the optimal patch count automatically
• Optionally toggle Suppress left clip border (-L) — suppressing it gains ~15 mm of printable width for extra patches; leave it on unless you use a physical paper-clip jig
• Click Generate Chart — the TIFF preview appears on the right when done

Step 2 — Print Chart

• Select your printer from the dropdown (click ↺ to refresh the list)
• Configure paper slot, media type, and print quality if needed
• Use No Color Adjustment in your printer driver to bypass color management when printing
• Click Print Page X for each page of the chart

Step 3 — Measure Chart

• The .ti2 file from Step 1 is loaded automatically
• Follow the on-screen prompts from chartread
• Use Enter/Space to confirm each strip, ← → to navigate, ESC to abort

Step 4 — Build Profile

• Review the colprof settings (quality, algorithm, gamut mapping, etc.)
• Click Build Profile — the resulting .icm file is saved in the same folder as the chart
• Install the profile in macOS via ColorSync Utility or by double-clicking the .icm file

Step 5 — Check & Refine

• The .ti3 measurement file from Step 3 is loaded automatically
• Click Run profcheck to evaluate the finished profile — per-patch ΔE statistics are shown in the log
• Patches above the ΔE threshold are highlighted; click Re-measure patches to start a guided re-measurement of only those patches
• After re-measurement, click Build Profile again to incorporate the improved data
• Repeat until the profile accuracy meets your requirements

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Project Structure

ChromIQ/
├── main.py                    # Entry point
├── ChromIQ.spec               # PyInstaller build spec
├── requirements.txt
├── assets/                    # App icons and UI images
├── core/
│   ├── argyll_runner.py       # QProcess wrapper for ArgyllCMS tools
│   ├── file_manager.py        # Working folder and target name management
│   ├── logger.py              # Rotating file logger (~ChromIQ/chromiq.log)
│   ├── resource_path.py       # Asset path resolution for dev + frozen bundles
│   └── settings.py            # QSettings wrapper with typed defaults
├── data/
│   ├── parameters.yaml        # All targen/printtarg/colprof flags + tooltips
│   └── patch_db.py            # Empirical per-sheet patch capacity database
├── ui/
│   ├── main_window.py         # Top-level window, tab container, status bar
│   ├── parameter_widget.py    # Auto-generated flag widgets from parameters.yaml
│   ├── styles.py              # Fusion dark-theme QSS stylesheet
│   ├── tiff_preview.py        # Zoomable TIFF viewer widget
│   ├── tooltip_button.py      # ? icon with popover tooltip
│   ├── widgets.py             # Shared widget helpers (browse buttons, etc.)
│   ├── dialogs/
│   │   └── settings_dialog.py # Preferences dialog
│   └── tabs/
│       ├── tab_chart.py           # Step 1: chart creation
│       ├── tab_print.py           # Step 2: CUPS printing
│       ├── tab_measure.py         # Step 3: chartread measurement
│       ├── tab_profile.py         # Step 4: colprof profile building
│       └── tab_check_refine.py    # Step 5: profcheck quality check & refinement
└── workflow/
    ├── chart_creator.py       # targen + printtarg orchestration
    ├── cups_printer.py        # lp command wrapper
    ├── measure_manager.py     # chartread orchestration
    ├── postscript_generator.py
    ├── print_manager.py       # Printer enumeration (lpstat)
    └── profile_builder.py     # colprof orchestration

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Configuration

All settings are stored via QSettings (macOS: ~/Library/Preferences/ChromIQ.ChromIQ.plist) and can be adjusted in Preferences:

Setting	Default	Description
ArgyllCMS bin path	/Applications/Argyll/bin	Directory containing the ArgyllCMS executables
Preferred instrument	i1Pro	Pre-selects instrument in Guided mode
Preferred paper size	A4	Pre-selects paper in Guided mode
Output folder	~/ChromIQ/	Root folder for all chart/profile sessions

Each session creates a subfolder named after the target (e.g. ~/ChromIQ/Canon_A4_Matte_i1_2025-04-18_14-30/) containing all generated files for that run.

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How Patch Count Is Calculated

In Guided mode ChromIQ determines how many color patches to generate:

1. Direct lookup — for standard patch_scale (1.0) and margin_mm (6 mm), the empirical database in data/patch_db.py is consulted. Separate values are stored for charts with (-L) and without the left clip border.
2. Binary search fallback — for custom scale or margin settings, ChromIQ runs a series of quick targen/printtarg probes to find the maximum patch count that fits on a single page.

The database values were measured with Argyll 3.5.0 at 300 DPI. All common instrument/paper combinations are covered.

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Adding a New ArgyllCMS Parameter

Parameters are driven by data/parameters.yaml — no code changes needed:

- tool: printtarg
  flag: "-x"
  type: bool
  default: false
  label: "Some new option"
  tooltip_title: "Some New Option (-x)"
  tooltip_body: "What this option does."
  expert_only: true   # optional: hide under Expert section
  no_space: false     # set true if value attaches directly to flag (e.g. -il not -i l)

Save the file and restart ChromIQ — the new parameter appears automatically in Manual mode.

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Known Issues

This section will be updated as issues are resolved.

• Printing (Step 2): Direct TIFF printing via CUPS works, but color management behavior requires further testing.
• Measurement (Step 3): Some spectrophotometer models may require additional calibration steps not yet surfaced in the UI.
• Profile (Step 4): Advanced gamut mapping options (FWA, custom intents) are present in the UI but have not been fully tested across all instrument/paper combinations.
• Windows/Linux: Not tested. The app is developed and tested on macOS only. Linux support via CUPS is theoretically possible; Windows would require significant changes to the printing pipeline.

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Log File

ChromIQ writes a rotating log to ~/ChromIQ/chromiq.log (max 2 MB, 3 backups). All ArgyllCMS commands and their full argument lists are recorded here at INFO level, which is useful for debugging unexpected behaviour.

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License

To be determined.

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Acknowledgements

ChromIQ is built on top of ArgyllCMS by Graeme Gill — an outstanding open-source color management system. All color science heavy lifting is done by ArgyllCMS; ChromIQ is purely a GUI front-end.

A heartfelt thanks to soul-traveller for Argyll_Printer_Profiler — a printer profiling tool that is likely in a more mature and in several areas more comprehensive state than ChromIQ. If you prefer working with proven, pre-made test charts rather than randomly generated targets, his project includes an extensive collection of carefully selected charts that are an excellent fit for exactly that use case.