# SoilHue — Munsell soil color from photo > Mobile Munsell soil color classifier from photographs with on-device analysis. (iPhone/iPad app by Antonio J. Gonzalez.) - Source: https://appshunter.io/ios/app/soilhue/id6744872595 (this page in markdown: same URL + `.md`) - Developer: [Antonio J. Gonzalez](https://appshunter.io/developer/667099261) - Category: Productivity, Education - Price: Free - Rating: 1.00/5 from 1 App Store ratings · 1 written reviews indexed - Age rating: 4+ - Requires: iOS 17.6 · 3 MB - Languages: American English, European Spanish - Released: 2025-04-25 - Data updated: 2026-07-27 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/soilhue/id6744872595/reviews.md ## What is SoilHue? SoilHue identifies the Munsell color of a soil sample from a photograph taken with your device. It is built for pedologists, agronomists, geologists, archaeologists, conservators, soil-science students and anyone who works with soil color in the field. WHAT IT DOES • Calibrate the camera with an X-Rite ColorChecker Classic. SoilHue detects the card automatically inside your photo, rectifies its perspective, and computes a 3×3 correction matrix by least-squares fit over the 24 reference patches. • Take a photo of your soil sample (or pick one from your library) and select the area to analyze with a rectangle or a free-form polygon. • SoilHue averages the selected pixels in linear sRGB, applies your calibration matrix, and finds the closest match in CIE Lab among 293 chips derived from the official USDA Munsell renotation data. • Get the Munsell notation, an approximate USDA soil order (Histosol, Mollisol, Alfisol, Oxisol, Vertisol, Spodosol, Aridisol, Entisol, Inceptisol, Ultisol) and a short description. WHAT'S NEW IN 2.0 • 293 reference chips instead of 18. • ΔE94 in CIE Lab instead of Euclidean RGB. • Matrix 3×3 calibration replacing per-channel factors. • Automatic ColorChecker detection (Vision framework). • Printable calibration card (2-page A4 PDF, ICC sRGB). • Lighting check (warm/cool/atypical tint warning). • Real .xlsx export. • Accessibility, dark mode and stability improvements. DATA & PRIVACY • All analysis runs on-device. No image, sample or location ever leaves your phone. • Samples are stored locally in your app sandbox. iCloud sync is planned for a future release. • Location is captured only when you explicitly grant it. REQUIREMENTS • iPhone or iPad running iOS 17.6 or later. • A reasonably calibrated camera. Recommended: X-Rite ColorChecker Classic for best results. A basic calibration card is included for casual use. NOTES The USDA soil order classification is a heuristic orientation, not a definitive diagnosis — real classification depends on horizon, chemistry, texture and other field properties. Calibrations saved with versions before 2.0 are not compatible with the new color engine; the app will ask you to recalibrate. Contact: soilhue@ajgb.eu — Web: ajgb.eu/apps/soilhue ## Key features - Soil color identification from photos - Munsell notation and USDA soil order - Advanced camera calibration - On-device image analysis - Export data to .xlsx - Lighting condition check ## Recent user reviews (1 of 1) All indexed reviews: https://appshunter.io/ios/app/soilhue/id6744872595/reviews.md ### 1/5 — does not work *2025-06-22* Error error.generic is the message that is provided by the app each time it is operated on an iPhone 16 Pro. Regardless the calibration, location or area versus polygon options the same error appears every time the application is operated **Developer response:** Hi, First of all, thank you very much for your feedback and for taking the time to report the error. I’m really sorry that your experience with SoilHue wasn’t as expected, and I completely understand your frustration. SoilHue is a personal hobby project I work on in my spare time, and it’s offered for free with no monetization. That said, feedback like yours is incredibly valuable and helps me make the app better for everyone. I believe I’ve identified and fixed the issue you described, and the latest version of the app includes this correction. Thank you again for your honesty. If you decide to give SoilHue another try, I’d be very happy to hear your thoughts or any suggestions you might have. Thanks again for helping improve SoilHue! ## Frequently asked questions about SoilHue ### What is SoilHue? SoilHue is a mobile application designed to identify the Munsell color of a soil sample directly from a photograph taken with your device. It provides the Munsell notation and an approximate USDA soil order. ### How does SoilHue calibrate the camera? SoilHue calibrates the camera using an X-Rite ColorChecker Classic. It automatically detects the card in your photo, rectifies its perspective, and computes a correction matrix for accurate color analysis. ### Is my soil data private with SoilHue? Yes, all analysis runs on-device, meaning no image, sample, or location data ever leaves your phone. Samples are stored locally within the app's sandbox. ### What devices is SoilHue compatible with? SoilHue is compatible with iPhones and iPads running iOS 17.6 or later. It requires a reasonably calibrated camera for best results. ### Does SoilHue have ads? No, SoilHue does not contain advertisements. It is a free application with no in-app purchases or ads. ### What are the new features in SoilHue 2.0? Version 2.0 includes 293 reference chips, improved color matching with ΔE94 in CIE Lab, automatic ColorChecker detection, printable calibration cards, lighting checks, and .xlsx export. ### How often is SoilHue updated? The latest version, 2.0, was released on May 19, 2026, indicating active development. Users can expect updates to improve functionality and stability. ### What is the user rating for SoilHue? SoilHue has a rating of 1.0 stars from 1 rating. This indicates a very limited number of user reviews currently available. ## Version history (last 4 releases) ### 2.1 — 2026-07-24 Camera permission fixes: clearer error messages and a direct Settings button. Change permissions, return to the app, and it automatically retries ### 2.0 — 2026-05-19 SoilHue 2.0 brings a complete rewrite of the color analysis engine: • Far more accurate Munsell classification — comparison now happens in CIE Lab (ΔE94) against 293 reference chips from the official USDA Munsell renotation, replacing the previous 18-entry table. • Camera calibration uses a 3×3 matrix least-squares fit over the 24 ColorChecker patches — captures cross-channel correction the old per-channel factors couldn't. • Automatic ColorChecker detection: the app finds and rectifies the card inside your photo, no need to fill the frame. • Print your own calibration card — share a 2-page A4 PDF with embedded ICC sRGB profile straight from the calibration screen. • Lighting check: a warm/cool/atypical light tint is flagged so you remember to take samples under the same light. • Excel (.xlsx) export now produces a real workbook. • A persistent banner reminds you to calibrate before analyzing. • Accessibility, dark mode and stability improvements throughout. Important: calibrations saved before 2.0 are not compatible with the new engine and are discarded automatically — the app will ask you to recalibrate on first launch. Your saved samples are preserved. ### 1.1 — 2025-06-29 Fixed a bug that affected soil color analysis when using certain device cameras or gallery photos. Thanks for your feedback and support! ### 1.0 — 2025-04-25 No release notes. ## More apps by Antonio J. Gonzalez - [Nonogram Solver Plus](https://appshunter.io/ios/app/nonogram-solver-plus/id6449408629) - [MinimalBASIC](https://appshunter.io/ios/app/minimalbasic/id6466343064) - [Sudoku Challenger](https://appshunter.io/ios/app/sudoku-challenger/id6736710760) - [Kanban Lite Snap](https://appshunter.io/ios/app/kanban-lite-snap/id6745480281) - [SlidingPhoto](https://appshunter.io/ios/app/slidingphoto/id6751211479) All apps by Antonio J. Gonzalez: https://appshunter.io/developer/667099261 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-27.*