ChromIQ

ChromIQ is a free, open-source desktop app that builds custom ICC printer profiles — the colour "fingerprint" that tells your computer exactly how your printer, ink, and paper reproduce colour. With an accurate profile, what you see on screen is what comes out of the printer.

Under the hood it drives ArgyllCMS, the gold-standard open-source colour engine, through a friendly five-step wizard. ArgyllCMS does all the colour science; ChromIQ gives it a calm, guided interface so you never have to memorise a single flag.

[!TIP] What is new in 4.3: the Measurement Report with six report types, limit sets that include the published values of ISO 12647-7 and ISO 12647-8, evenness across the sheet, trend graphs and PDF reports; 190 built-in chart presets (154 in 4.2) with a gear button to choose which are listed; and ChromIQ complete in 14 languages, Ukrainian among them. The full list is in the release notes.

[!NOTE] New to printer profiling? That's exactly who ChromIQ is for. Every screen has a clickable ⓘ icon that explains, in plain language, what the step does, what you need ready (device plugged in, paper loaded…), and what comes next. The in-app tooltips are the real manual — this README is the map.

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Table of contents

• What you'll need
• Download & install
  • macOS
  • Windows
  • Linux (beta)
  • Installing ArgyllCMS
• The five-step workflow
• Screenshots
• Feature highlights
• Troubleshooting
• Configuration & logs
• For developers
  • Want to add an instrument?
• Reporting issues & feedback
• License
• Acknowledgements

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What you'll need

To build a profile you need three things:

1. A printer — any inkjet (RGB, CMYK, or extended-gamut with extra inks).

2. A spectrophotometer — the device that "reads" the printed colours. ChromIQ supports:

   Code	Instrument
   i1	i1Pro / i1Pro 2 / i1Pro 3
   p3	i1Pro 3 Plus
   CM	ColorMunki / i1Studio / ColorChecker Studio
   SS	SpectroScan (flatbed XY table)
   CR30	ChnSpec CR30, a low-cost hand-held spectrophotometer with no ArgyllCMS support: ChromIQ drives it itself, over USB and Bluetooth

   In beta (off until you turn it on in Preferences → Beta; with it off, ChromIQ works exactly as before):

   Code	Instrument	Contributed by
   FD9	Konica Minolta FD-9, an automatic chart reader that measures the whole sheet by itself, over your network (Ethernet), with ChromIQ's own driver and no Konica Minolta software. Tested on one FD-9 on macOS so far: your report helps	lessbones, thank you!

   Your instrument is not listed? See Adding an instrument.

3. ArgyllCMS installed on your computer — ChromIQ looks for it automatically and walks you through installing it if it's missing. See Installing ArgyllCMS.

ChromIQ itself runs on macOS, Windows (Intel/AMD and ARM64), and Linux (x86_64 and aarch64, currently beta).

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Download & install

Grab the build for your system from the latest release. The pre-built downloads are all most people need — you only need the from-source route if you want to modify the code.

macOS

Requires macOS 13 Ventura or newer (the Qt framework inside ChromIQ sets this floor — on macOS 12 and older the app cannot start). On an older Mac, ChromIQ can still run from source with an older Qt: install Python 3.12+, then pip install "PyQt6==6.8.*" "PyQt6-WebEngine==6.8.*" with the other requirements and start python main.py.

There are two ways to install ChromIQ on a Mac. Homebrew is the easiest: one command installs ChromIQ and ArgyllCMS together and keeps both up to date. Prefer a plain download? See Install by hand below.

Install with Homebrew

Homebrew is a free, widely used package manager for macOS. If you don't have it yet, install it first: copy the one-line command from brew.sh into Terminal and follow what it says.

Then install ChromIQ:

brew install --cask itsab1989/chromiq/chromiq

That's it. What this does for you:

• ArgyllCMS comes with it. Homebrew installs it as argyll-cms, and ChromIQ finds it on first launch, so there is nothing to set up.
• ChromIQ opens straight away. ChromIQ is not notarised by Apple, so macOS would normally block it the first time you open it. The Homebrew cask removes that download block (the "quarantine") from the installed app, so there is no warning and no right-click → Open step.
• Your Mac's architecture is picked for you: the Apple Silicon build on an M-series Mac, the Intel build on an Intel Mac.

Want to try the newest beta? Install chromiq@beta instead:

brew install --cask itsab1989/chromiq/chromiq@beta

chromiq only ever installs stable releases. chromiq@beta always follows the newest release, beta or stable, so when a stable version comes out after its betas, beta users get it too. Only one of the two can be installed at a time.

Everyday commands (use chromiq@beta in place of chromiq if that is the one you installed):

To	Run in Terminal
Update ChromIQ	brew upgrade --cask chromiq
Switch from stable to beta	brew uninstall --cask chromiq and then brew install --cask itsab1989/chromiq/chromiq@beta
Switch from beta back to stable	brew uninstall --cask chromiq@beta and then brew install --cask itsab1989/chromiq/chromiq
Uninstall ChromIQ	brew uninstall --cask chromiq
Uninstall and also remove ChromIQ's settings, logs and caches	brew uninstall --zap --cask chromiq

Good to know:

• Your projects are always kept. Nothing Homebrew does touches your projects in ~/ChromIQ: not an update, not switching between stable and beta, not uninstalling, and not --zap. Switching and plain uninstalling keep your settings too.
• ArgyllCMS stays installed when you uninstall ChromIQ. If you no longer need it, remove it with brew uninstall argyll-cms.
• When ChromIQ tells you a new version is out, update with brew upgrade --cask chromiq rather than downloading the DMG, so Homebrew stays in charge of the app. Homebrew gets each release shortly after it is published.
• ChromIQ already in your Applications folder? If you installed it by hand before, Homebrew stops with "It seems there is already an App at '/Applications/ChromIQ.app'". Move the old ChromIQ to the Trash and run the install command again. Your projects and settings are not stored inside the app, so nothing is lost. (Adding --force to the install command replaces the old app in one step instead.)
• The Homebrew casks live in itsab1989/homebrew-chromiq and are updated automatically with every release.

Install by hand

1. Download the universal DMG — ChromIQ-macOS-universal_<version>.dmg (works on both Apple Silicon and Intel).
2. Open the DMG, then drag ChromIQ into your Applications folder.
3. Eject the DMG (⌘E).
4. The first time only: open Applications, right-click ChromIQ → Open, then click Open in the dialog. This tells macOS you trust the app.

[!TIP] Right-click → Open shows only a "Done" button (macOS Sonoma 14+)? Run this once in Terminal, then double-click ChromIQ normally:

xattr -dr com.apple.quarantine /Applications/ChromIQ.app

Windows

1. Download the build for your PC:
   • ChromIQ-Windows-x64_<version>.zip — Intel/AMD (most PCs)
   • ChromIQ-Windows-arm64_<version>.zip — ARM64 (e.g. Snapdragon X laptops)
2. Right-click the ZIP → Extract All…, open the extracted ChromIQ folder.
3. Double-click ChromIQ.exe.

[!TIP] "Windows protected your PC" / Defender flags the EXE? This is the usual false positive for open-source apps that aren't code-signed yet — see Troubleshooting for how to allow it. The full source is in this repo and every release is built by GitHub Actions from its matching tag.

Linux (beta)

1. Download the build for your machine:
   • ChromIQ-Linux-x86_64_<version>.tar.gz — Intel/AMD
   • ChromIQ-Linux-aarch64_<version>.tar.gz — ARM (Raspberry Pi 4/5, ARM workstations)
2. Extract and run:

   tar xzf ChromIQ-Linux-x86_64_*.tar.gz
   ./ChromIQ/ChromIQ
   

[!TIP] qt.qpa.plugin: … xcb-cursor0 … on launch? Install the missing library — see Troubleshooting.

Linux support is beta: ChromIQ runs, but the full workflow hasn't been exercised against real hardware yet. Please report what works (and what doesn't) via Discussions or the issue tracker.

Installing ArgyllCMS

ChromIQ needs ArgyllCMS 3.5.0 to do the colour work. It is not inside the ChromIQ download: you install it once, separately, and ChromIQ finds it automatically. If you installed ChromIQ on a Mac with Homebrew, this is already done for you.

OS	How to install
macOS	Installed ChromIQ with Homebrew? Then ArgyllCMS is already there. Otherwise run brew install argyll-cms, or download from argyllcms.com, unzip, and move the folder into /Applications (e.g. /Applications/Argyll_V3.5.0/).
Windows	Download the win64 build from argyllcms.com and extract to C:\Program Files\ArgyllCMS\.
Linux	sudo apt install argyll · sudo dnf install argyllcms · sudo pacman -S argyllcms, or download from argyllcms.com.

On first launch ChromIQ searches automatically — the system PATH, Homebrew, MacPorts and any Argyll* folder in /Applications on macOS; the standard install folders on Windows; /usr/bin and common paths on Linux. If it can't find ArgyllCMS, a setup guide opens. You can also point it manually any time:

Preferences (⌘, on macOS, Ctrl+, elsewhere) → Auto-detect to search again, or Browse to the ArgyllCMS bin folder, then Test binaries to confirm it works.

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The five-step workflow

ChromIQ is organised as five numbered tabs. Walk left to right and you have a finished, installed profile.

	Step	What happens	ArgyllCMS tool
1	Create Chart	Generate a test chart with the ideal number of colour patches for your instrument, paper, and page count.	targen + printtarg
2	Print Chart	Send the chart to your printer with colour management switched off (so you measure the printer's raw behaviour).	CUPS / native dialog
3	Measure	Scan the printed patches with your spectrophotometer.	chartread
4	Build Profile	Turn the measurements into a finished .icc profile and install it.	colprof
5	Check & Refine	Score the profile's accuracy, view its 3D gamut, and re-measure only the worst patches to improve it.	profcheck + iccgamut

Every step offers two modes:

• Guided — pick instrument, paper, and page count; ChromIQ chooses sensible, empirically-tuned defaults for everything else.
• Manual — every ArgyllCMS flag is exposed, with a live preview of the exact command that will run. Save your favourite setups as named presets.

Step 1 — Create Chart

Choose Guided or Manual, name your target, and click Generate Chart. The patch grid appears in the preview on the right. Optionally tick Refinement profile to base a second, improved pass on an existing .icc/.icm.

Or start from one of 190 ready-made chart presets (154 in 4.2), grouped by instrument: ColorMunki / i1Studio / ColorChecker Studio, i1Pro / i1Pro 2 / i1Pro 3, i1Pro 3 Plus, CR30, scanner, and Red River Paper.

New in 4.3: the gear button beside the presets folder opens Settings for built-in presets, which lists every built-in preset with a tick box. The ticked ones are listed directly; the rest wait under an arrow at the end of their group, so nothing is removed. ChromIQ starts you on a few per instrument and paper size, and only the changes you make are kept, so a later release can still improve that starting list. On a verification run, Which presets can be used for verification? lists every preset against the metrics the report you plan asks of a chart, and says which of them each chart can answer, and why not.

Step 2 — Print Chart

Pick your printer and print the chart. On macOS the native print dialog is now the default — ChromIQ opens the OS print sheet and locks the driver's colour controls off for you (via PyObjC), so colour management can't sneak back in. The per-brand steps for confirming colour is disabled are shown right in the tab. On Windows the Windows print dialog opens the same way by default, with per-brand instructions for switching the driver's colour adjustment off; the chart is placed at exactly 100 % size, centred on the paper.

[!TIP] Prefer the old behaviour on macOS? Turn Use default macOS printer dialog off in Preferences and ChromIQ falls back to its direct PostScript pipeline, which bypasses colour management automatically with no dialog at all — handy for batch printing.

New in 4.3.8, the same on Windows: turn Use default Windows printer dialog off and ChromIQ sends a PostScript printer the chart directly, bypassing its driver, with its own RGB, CMYK or ink values and at 100 %. You pick the paper, media type and quality on the Print Chart tab. A printer that does not understand PostScript (most home and photo inkjets) still gets an RGB chart through the Windows dialog; CMYK and multi-ink charts are refused there, because the driver would change their colours.

Step 3 — Measure

The chart from Step 1 loads automatically. Follow the on-screen prompts: Enter/Space confirms a strip, and F / B step forward and back between strips (the on-screen strip highlight follows along). Misread a strip? The dialog offers Retry, Skip Stripe, or Save Partial & Quit (which lets you resume later with one click).

With a ChnSpec CR30 the chart is read patch by patch: ChromIQ finds the instrument over USB or Bluetooth, calibrates it with you step by step, draws the instrument's 33 mm body to scale on the patch it is asking for, and takes a reading on Space or Enter so the instrument is never nudged by its own button. A magnet near the measuring opening (a laptop lid under the paper is enough) makes a CR30 return its white-tile value instead of your patch; ChromIQ learns that value and refuses such a reading rather than writing it into your profile. Twenty-six ready-made CR30 charts are in the Presets dropdown (twenty in 4.2; six more in 4.3). On Windows, Preferences ▸ Instrument drivers… installs the drivers for ArgyllCMS's instruments and for the CR30 from one place, and Tools ▸ Instruments writes a Bluetooth report for when the instrument will not connect.

Step 4 — Build Profile

Review the colprof settings and click Build Profile. Then Install Profile copies it to the right place for your OS so every app can use it. To iterate, click ← Use as Pre-conditioning to seed an improved second pass. In Manual mode you can also control black generation (-k/-K) — how much black ink the profile uses for dark colours — with every rule explained in plain language. An optional, experimental ChromIQ-built profile engine (off by default) can build here too — see the experimental engine below.

Step 5 — Check & Refine

Click Analyse Profile Quality to get per-patch ΔE accuracy scores. The 3D Gamut Volume viewer on the right shows the range of colours your profile can reproduce — and you can load a second profile to compare them (volume difference, overlap, and coverage in both directions). Patches that scored poorly can be re-measured in one click, then rebuilt.

[!NOTE] Optional calibration mode. Turn on Enable calibration options in Preferences to expand Step 4 into a three-part panel — Create Calibration File (printcal), Build Profile (colprof), and Apply Calibration (applycal) — for per-channel ink linearisation before profiling.

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Screenshots

Every screen is shown in both Dark and Light appearance (ChromIQ also has a System/Auto mode that follows your OS live). Click any step to expand it.

	Dark	Light
Guided
Manual

	Dark	Light
Native print dialog (macOS default)
PostScript pipeline (no-dialog fallback)

	Dark	Light
Guided
Manual
Expected vs. measured overlay
"All stripes read" prompt

	Dark	Light
Guided
Manual
"Profile built" — what next?
Calibration mode — Create Calibration File (printcal)
Calibration mode — Apply Calibration (applycal)

	Dark	Light
Analysis run
Quality assessment (per-patch ΔE)
Manual options
3D gamut comparison (two profiles)

Dark	Light

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Feature highlights

Guided & Manual, side by side

• Guided uses an empirical patch-capacity database to pick the right patch count for your instrument/paper/page combo — no guesswork.
• Manual exposes every targen / printtarg / colprof flag with a live command preview, plus per-tab Save as Defaults and named presets.

Printing that just works

• PostScript Level 2/3 pipeline (macOS) that disables colour management automatically — no driver fiddling, no ColorSync in the way.
• Automatic TIFF fallback for AirPrint / driverless printers that reject PostScript, plus 16-bit TIFF output for true 16-bit printers and RIPs.
• Native OS print dialog option — on macOS it even locks the driver's colour controls via PyObjC so they can't be re-enabled by accident; on Windows/Linux it shows per-brand instructions for turning ICM off.
• Preflight confirmation with paper-size and orientation checks, offline printer detection, and a Clear Print Queue button for stuck jobs.

Serious colour science

• Full colprof option set — illuminants (D50/D65/A/C/F5/F8/F10), observers (1931 2°, 1964 10°, 2015 variants), FWA compensation, gamut-mapping intents.
• RGB, CMYK, and multi-channel (DeviceN) targets — from 4-channel CMYK to extended-gamut ink sets (CMYK plus Orange, Green, Light Cyan, …). The UI lets you stack up to 11 colorant overrides (-D); ArgyllCMS supports up to 16 device channels.
• Pre-conditioning (second-pass) refinement — drive a targen -c pass from an existing profile to iteratively improve it, with automatic archiving.
• CIECAM02 viewing-condition presets for correct perceptual/saturation tables.
• ICC media attributes (colprof -Z) embedded in the profile header.
• Black generation control (colprof -k/-K) in Build Profile → Manual — choose how much black ink your profiles use for dark colours, from pure CMY to maximum black, with plain-language explanations of every rule.

Experimental: the ChromIQ profile engine (beta)

[!WARNING] Everything in this section is experimental and off by default. The engine is validated against a synthetic test bench, ~2 000 automated tests, and ArgyllCMS's own tools — but not yet on real multi-ink printing hardware. Argyll colprof remains the default and the reference. If you try the engine, always print a test image before trusting a profile for real work.

ChromIQ now contains its own profile builder next to Argyll colprof. Enable it under Settings → Beta → ChromIQ profile engine and the Build Profile tab lets you build with either — same measurements, same options, so you can build both and compare. Why it exists: colprof cannot build profiles for printers with more than four inks; the engine can — CMYK plus orange, green, violet, light inks — closing the whole multi-ink loop inside ChromIQ (design the chart, print, measure, build, refine).

• Three accuracy modes (Settings → Beta): Fast (ChromIQ's own implementation of colprof's method, validated against Argyll), Bit-exact (real colprof for standard printers; a bundled helper runs Argyll's genuine gamut-mapping code for multi-ink ones), and Maximum accuracy (averages your repeated white/black patches, picks smoothing for your specific chart by cross-validation, survives a smudged patch and names it so you can remeasure, and honours the total-ink limit in the least-damaging way).
• ICC v4 output — build v2 (classic, most compatible), v4 (modern, with a built-in integrity checksum), or Both. Engine-only for now.
• Spectral physics model — a physical model of ink-on-paper for multi-ink printers with spectral measurements. It must beat the standard model on your own chart before it is used, so it can only win or change nothing.
• Measurement noise handling — diagnoses how noisy your measurement really was and only engages when the chart is measurably noisy; on a clean chart your profile is bit-for-bit unchanged.
• Out-of-gamut rendering — keep the Argyll-matched rendering (default) or try ChromIQ's mathematically-exact alternative and judge the look on your own prints.
• Check & Refine for multi-ink profiles — the accuracy check works on 6-ink and larger profiles, which stock profcheck won't read.

Quality check & 3D gamut viewer

• profcheck integration with per-patch ΔE statistics and quality grading.
• Targeted re-measurement — only the patches above your ΔE threshold.
• Interactive 3D gamut viewer (iccgamut + viewgam + X3DOM) with volume in ΔE³, Lab / CIECAM02 Jab, cusp markers, and edge plots.
• Profile-vs-profile comparison — volume delta, intersection volume, and bidirectional coverage.

Design your own chart — layout editor & colour-set generator

Most people never need this — Guided mode already picks a great chart. But when you want full control over which colours you measure and how the sheet is laid out, the chart layout editor (Tools → Edit / create chart layout) is a complete design surface:

• Start from anything — load an existing .ti2, pull in the chart you just made on the Create Chart tab, or build a fresh patch set from a targen seed, pasted colours or the colour-set generators.
• Rearrange freely — move patches and whole strips with Front / Up / Down / Back, and see the printed sheet redraw in a live, multi-page preview.
• Recolour patches and spacers — set or nudge patch colours, edit the spacer palette, or paint individual separator strips, all while ChromIQ keeps the measurement data and the printed pixels perfectly in sync.
• Combine charts — append or prepend the colours from another .ti2/.ti1/ .ti3/i1Profiler file to merge two targets into one.
• See it in 3D — the 3D distribution viewer plots your whole patch set as an interactive RGB cube so you can spot gaps and clumps at a glance.
• Save & apply pushes your custom layout straight back into the Create Chart tab, ready to print.

Build a target around the colours you actually print. The colour-set generator (in New chart and Add patches) lets you stack any mix of these, with live patch counts and automatic de-duplication so combined sets never double up:

• 3D RGB cube — even coverage across the whole colour range.
• Skin tones — light→dark ramps through all six Fitzpatrick phototypes.
• Blues / turquoise and Greens (foliage) — denser sampling of skies, water, forests, and foliage.
• Near-neutral greys — a neutral ramp plus subtle hue rings for clean, cast-free greys.
• Saturated edges and gamut faces — the most vivid colours your printer can reach, for accurate gamut boundaries.
• Highlights & shadows — extra detail at the bright and dark ends where printers struggle most.
• Pastels — soft, low-chroma colours across every hue.
• From image — load a photo and ChromIQ extracts its most representative colours, so you can profile around a specific image or palette.
• White & black anchors and Fill remaining gaps — guarantee pure paper-white/black, then scatter extra patches into the sparsest parts of the set up to a target count.

Ink devices, not just RGB. The New chart and Add patches windows can design charts in CMYK or CMYK + extra inks (added as removable chips), with a first-class ink limit and an optional preconditioning profile. Ink-native colour sets — per-ink ramps, ink-pair and ink-triple overprints, a rich-black ramp, grey-balance rings re-centred on your printer's measured neutral — join the look-based sets above, which translate into real ink values through the preconditioning profile. Charts save as true separated TIFFs (each ink a named channel, opens correctly in Photoshop and RIPs) with an optional press-ready vector-PDF export, and the preview gains a per-ink inspector. The chart tools themselves are fully supported; note that building a profile from charts with more than four inks requires the experimental profile engine.

Tools menu — standalone utilities

The masthead Tools button opens a menu of conversions and checks you can run on their own, outside the five-step flow:

• Measurements: Read single patches (spot readings off any material), Average measurements (combine repeat reads of the same chart for lower noise), Merge measurements (fold extra measurements into an existing set), Inspect a measurement, and Measurement report (accuracy & trends).
• Charts & patch sets: Edit / create chart patch set, the full layout editor and colour-set generator described above (reorder strips, recolour patches and spacers, combine charts, generate custom colour sets), and Show patch distribution (3D).
• Scanner & camera: Create scanner or camera target (.cht + .cie) and Build profile with scanner or camera (from a scan or photo).
• i1Profiler interchange: Convert TI1 → i1Profiler, Convert i1Profiler → TI3 and Convert i1Profiler → TI1, to move charts and measurements between ChromIQ/ArgyllCMS and X-Rite i1Profiler.
• Profiles: Inspect a profile, Verify a profile (independent check), Verify against reference, Create device-link profile, Apply a device-link to an image, and Soft-proof / check an image.
• Instruments: CR30 Bluetooth report (for when it will not connect). The Windows driver installer is under Preferences ▸ Instrument drivers….
• Language: Translate / edit language.

Your work, kept in order

• Every run keeps its own chart, measurement, settings and description. Going back to an older run shows the settings that run was actually made with — not the last ones you happened to type.
• Nothing is deleted, only archived. A measurement you replace, a chart you regenerate and a calibration you redo all move to an old/ folder with the date, and the window says so before you commit.
• Calibration is a run type of its own: its chart, measurement and .cal file live in the project's cal/ folder, shared by every run, and each profile records which calibration it was built with.
• Verification runs, kept as history. Measure a chart printed through a finished profile and the result is filed by date with its own report. Earlier checks are never overwritten, so you can watch how a profile changes over months.

Measurement Report (new in 4.3)

Any measurement becomes a Measurement Report, from the Measure tab or from Tools ▸ Measurement report (accuracy & trends). Choose what kind of document you need and which set of limits it is judged against. ChromIQ measures every metric your chart can answer and marks each one PASS or FAIL against its limit (INFO where a set gives it no limit), and marks N-A, with the reason, the ones this chart cannot answer.

• Six report types: Colour summary (one page), Full colour check, Grey and tone check, Printing record (not graded), Validation print check (ISO 12647-8) and Contract proof check (ISO 12647-7). The run type decides what is offered: the sheet a profile was built from gets a printing record; a verification gets the judged types, the two ISO types among them; a calibration gets the judged types without the two ISO types, and can still be judged against an ISO limit set.

• Limit sets, in the Report limits window:

  • ChromIQ's own: ChromIQ default (2.0 on the averages, 3.0 on the maxima), ChromIQ tight (half of those accuracy limits) and Quick check (twice them), each with grey-balance and evenness limits of its own;
  • ISO 12647-7:2016 values (contract proofs) and ISO 12647-8:2021 values (validation prints), the standards' published tolerance values, read-only;
  • Custom ISO 12647-7 and Custom ISO 12647-8, alternatives to each standard that start from limits researched from industry practice and ChromIQ's own numbers, not the standard's, and are yours to change.

  One report uses one limit set for every measurement in it.

• Grey balance, tone ramps and evenness: the grey ramp is judged for colour cast (the mid-tone ramps with it under every limit set except the read-only ISO 12647-7 one), and the sheet is split into nine areas and compared, so a band or an uneven dry-down shows up as a number. The measurement's own noise is taken out first, so the number is the unevenness itself, and the ISO sets judge it with the standards' figures converted to ChromIQ's method.

• A saved report stays as it was saved. Reopening it shows exactly the figures, verdicts and limits it was made with; a new or updated report is worked out by the version you are running.

• Trend graphs: every judged metric over time, across your dated verifications, each with its own limit line.

• Save report as PDF: the whole report, or the one-page summary to hand over with a job.

[!IMPORTANT] ChromIQ measures against published values; it does not certify. The ISO 12647 values are applied to the chart you printed, not to that standard's own control strip and chart, so a report can never say that a print conforms to a standard. What ChromIQ does is measure as many of the standard's values as your chart allows, say which it checked and which it did not, and let you follow them over time. Requirements ChromIQ cannot measure at all stay in the limits table, marked ✕, so you can see what the standard asks.

A calm, modern app

• Light, Dark and Neutral appearance, or System (Auto), which follows your OS theme live. Neutral is a designed greyscale for anyone who would rather the app did not use colour to say things.
• Sounds during measurement — a strip accepted, a patch misread, a session finished. Choose a pack or your own files under Preferences → Sounds, so you can keep your eyes on the chart instead of the screen.
• Fourteen languages, complete: English plus German, Spanish, French, Italian, Dutch, Portuguese, Swedish, Norwegian, Polish, Russian, Ukrainian, Japanese and Chinese. Every button, message, tooltip and help text, not just the menus. Ukrainian is new in 4.3.
• Per-tab onboarding tooltips, live command preview, and a zoomable multi-channel TIFF preview (RGB, CMYK, extended-gamut).
• Session restore, rotating log file, and a built-in update checker.
• Self-documenting chart TIFFs — the exact commands and ChromIQ version are stamped into each generated TIFF's margin.

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Troubleshooting

ChromIQ is packaged with PyInstaller and isn't code-signed yet, so unsigned-app heuristics sometimes flag it. This is common and not specific to ChromIQ.

• SmartScreen warning: click More info → Run anyway.
• EXE disappeared after extracting: open Windows Security → Virus & threat protection → Protection history, find ChromIQ, and choose Restore / Allow on device.
• Keeps recurring: add the ChromIQ folder under Virus & threat protection → Manage settings → Exclusions → Add an exclusion → Folder.

Install the missing system library:

sudo apt install libxcb-cursor0     # Debian / Ubuntu
sudo dnf install xcb-util-cursor    # Fedora / RHEL
sudo pacman -S xcb-util-cursor      # Arch

Open Preferences → Auto-detect. If that fails, click Browse, select the ArgyllCMS bin folder, and click Test binaries. See Installing ArgyllCMS for the expected locations.

The CUPS/PostScript auto-bypass is macOS-only. On Windows and Linux you must disable ICM/colour management in the printer driver before printing a profiling target — ChromIQ shows per-brand instructions in the Print tab and can't do this for you without CUPS.

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Configuration & logs

Settings are stored with QSettings (on macOS, ~/Library/Preferences/ChromIQ.ChromIQ.plist). The Preferences dialog (⌘,) exposes:

Setting	Default	What it does
ArgyllCMS bin path	auto-detected	Folder containing the ArgyllCMS executables
Output folder	~/ChromIQ/	Where chart/profile projects are saved
Restore last active tab on launch	On	Reopen on the last-used tab
Restore last session on launch	Off	Reload the last project's files at startup
Enable calibration options	Off	Unlock the printcal → applycal workflow
Use default macOS printer dialog	Off	Use the native print sheet instead of the PostScript pipeline (macOS)
Confirm print settings before sending	On	Show a preflight summary before each job
Use app theme colours for 3D gamut viewer	On	Tint the gamut mesh with ChromIQ's palette

Each project lives in its own folder under ~/ChromIQ/<project-name>/, holding every generated file for that run (chart, measurements, profile, quality reports). See docs/dev_folder_layout.md for the exact layout.

Logs (rotating, max 5 MB × 5 backups) record every ArgyllCMS command run — the fastest way to diagnose a problem:

• macOS: ~/Library/Logs/ChromIQ/chromiq.log
• Windows: %LOCALAPPDATA%\ChromIQ\Logs\chromiq.log
• Linux: ~/.local/state/ChromIQ/logs/chromiq.log

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For developers

Most users don't need this section — the pre-built downloads above are all you need. Continue here only to run or modify the source.

Run from source

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

Requires Python 3.12+. Key dependencies: PyQt6 / PyQt6-WebEngine (≥ 6.11), Pillow, PyYAML, NumPy, tifffile, imagecodecs, certifi, and (macOS only) pycups and pyobjc. See requirements.txt.

Run the tests

source .venv/bin/activate
QT_QPA_PLATFORM=offscreen pytest    # ~1–2s, 284 tests

Build a standalone app

pip install pyinstaller
pyinstaller ChromIQ.spec            # macOS → dist/ChromIQ.app
#           ChromIQWin.spec  (Windows)   ChromIQLinux.spec  (Linux)

ArgyllCMS binaries are not bundled — install them separately and set the path in Preferences.

Refresh the documentation screenshots

The screenshots in docs/ are generated by a script that drives the real app:

scripts/make_sample_projects.sh     # build sample data (needs ArgyllCMS)
python scripts/capture_screens.py   # opens the app and captures docs/*.png

# The landing page (docs/index.html) has its own set, framed without the
# frames under the Create Chart preview, and inlined into the page:
CHROMIQ_SHOTS_OUT=/tmp/landing CHROMIQ_SHOTS_CLEAN_PREVIEW=1 \
    python scripts/capture_screens.py
python scripts/splice_landing_shots.py /tmp/landing

The chart is built from a fixed seed, so both sets always show the same sheet and re-running either one reproduces it exactly.

How the architecture fits together

ChromIQ is a thin GUI over ArgyllCMS; the heavy colour science is all Argyll.

Directory	Purpose
core/	Settings, ArgyllCMS detection, the QProcess runner, file/project management, logging
data/	parameters.yaml (every CLI flag + tooltip) and the patch-capacity database
ui/	All Qt widgets — main window, the five tabs, shared TIFF preview, gamut panel, dialogs
workflow/	Business logic — chart creation, PostScript generation, printing, measuring, profiling

A few patterns worth knowing:

• data/parameters.yaml drives the UI. Add a parameter there — with tool, flag, type, default, tooltip_title, tooltip_body — and it appears in Manual mode automatically, no code changes needed. (no_space: true appends the value directly to the flag; expert_only: true hides it under "Expert".)
• All file paths go through Project / Run / Calibration in core/file_manager.py — never hard-code a filename pattern.
• ArgyllRunner is a singleton — only one ArgyllCMS process runs at a time.

More developer docs live in docs/ (folder layout, built-in presets, the i1Profiler export format, and more), and project-specific guidance is in CLAUDE.md. How to contribute is in CONTRIBUTING.md.

Want to add an instrument?

If you own a measuring instrument ChromIQ does not support yet, and you have a driver or a working connection to it, we would love your help. Start with docs/adding_an_instrument.md: it explains what to bring, which existing integration to model yours on (the CR30 or the FD-9), the Preferences > Beta option that keeps everyone else's ChromIQ unchanged, and every place an instrument has to be registered. If you work with a coding agent, hand it docs/adding_an_instrument_agent_prompt.md. The maintainers cannot test hardware they do not own, so your tests on the real device are an important part of the pull request.

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Reporting issues & feedback

You can reach all of these from inside the app — Preferences (⌘,) → Report a Bug… in the bottom row.

• Found a bug? Open a bug report. Please attach the log file (see Configuration & logs) — it captures every ArgyllCMS command and is usually the fastest path to a fix.
• Have an idea? Open a feature request.
• Question or open-ended chat? Use Discussions.

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License

ChromIQ is free software, licensed under the GNU General Public License v3.0 (see LICENSE). You're free to use, study, share, and modify it; if you distribute a modified version, it must stay free under the same license.

GPLv3 is the right fit because ChromIQ builds on GPL-licensed components (PyQt6 and pycups), so the combined application is, and remains, free and open source. ArgyllCMS (AGPLv3) is used at arm's length as a separate command-line program and is not bundled or modified, so its copyleft does not extend to ChromIQ's own code.

Everything ChromIQ ships that somebody else wrote — colour profiles, fonts, the plotly bundle, sounds, the test image — is listed with its terms in THIRD-PARTY-NOTICES.md.

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Acknowledgements

ChromIQ stands on the shoulders of ArgyllCMS by Graeme Gill — an outstanding open-source colour management system that does all the real colour science here. ChromIQ is purely a friendly front-end to it.

A heartfelt thanks to LackiUA for the complete Ukrainian translation, contributed on issue #198: 5,425 rows, every placeholder intact, and the keys their export did not cover left in English rather than guessed at.

A heartfelt thanks to soul-traveller for Argyll_Printer_Profiler — a mature, in several areas more comprehensive printer-profiling tool. If you prefer working from proven, pre-made test charts rather than randomly generated targets, his project ships an excellent curated collection for exactly that. Knut has also tested ChromIQ on his own printers and instruments from the early betas on, and most of the behaviour written down in docs/design/ was agreed with him on issue #182.