SW Maps vs SoilHue

SW Maps is a free GIS and mobile mapping app for collecting, presenting and sharing geographic information. Whether you are conducting a full scale GNSS survey with high precision instruments, need to collect large amount of location based data using nothing but your phone, or just need to view a few shapefiles with labels over a background map on the go, SW Maps has it all covered. Record points, lines, polygons and even photos and have them displayed over your choice of background map, and attach custom attribute data to any feature. Attribute types include text, numbers, an option from a predefined set of choices, photos, audio clips and videos. Conduct high accuracy GPS surveys using external RTK capable receivers over Bluetooth LE. Draw features on the map by adding markers, and measure distance and area. Reuse the layers and attributes of a previous project for another survey, or create templates and share them with other users. Share the collected data with other users as Geopackages, KMZ or shapefiles, or export them to your device storage. Also share and export recorded data as Spreadsheets or CSV files. All data is recorded and exported in the standard WGS84 Geographic coordinate system (EPSG:4326). Features -Online Base maps: Apple Maps or Open Street Map -Support for multiple mbtiles and KML overlays -Shapefile and Geopackage layers, with attribute categorized styling. View shapefiles in any coordinate system supported by the PROJ.4 library. -Add multiple online WMTS, TMS, XYZ or WMS layers and cache tiles for offline use. -Connect to external GPS receivers using Bluetooth for high accuracy surveying using RTK with built-in NTRIP client. Also record data from external receiver for post processing. -Define multiple number of feature layers, each with a set of custom attributes Feature Types: Point, Line, Polygon Attribute Types:Text, Numeric, Drop down Options, Photos, Audio, Video Save as Template for re-use or sharing -Record GPS tracks, with distance measurement -Label features based on attribute values. -Import feature layers from templates or existing projects. -Share or export collected data as KMZ (with embedded photographs) , shapefiles, GeoJSON, Geopackage (GPKG), XLS/ODS spreadsheets or csv files. -Share templates or projects with other users -Supports use of GTX geoid files. To use custom geoids, prepare a GTX file with offsets in meters from WGS84. This product is made in Nepal and is FREE (no Ads). If you find this useful, please let your friends know that you have used a product from Nepal. Spare sometime to visit this wonderful country and know the Nepali people.

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