SolStretch is a Shiny web application designed to apply decorrelation stretch to RGB raster images (TIFF or JPEG), enhancing visual contrast and improving feature visibility using a PCA-based transformation. This tool is especially useful for: Enhancing faint rock art and cave paintings Highlighting subtle color variations in sedimentary profiles and stratigraphy images 🆕 What’s new in version 1.3.0: ✅ Improved package installation process ⚠️ Error handling implemented for image loading and processing ⏳ Processing now includes a progress indicator 🔒 Added validation to ensure high_pct > low_pct 🧭 Cleaner interface with tabs and before/after comparison view 📚 Added a dedicated Help tab with user documentation 🧩 Image processing functions have been modularized 🎛️ Added RGB color channel controls Originally developed to assist in the visual enhancement of archaeological and parietal art images. 🔗 Try locally with R shiny::runApp("SolStretch_1.3.0") --- 📖 Citation: If you use this tool, please cite: Solano García, J. A. (2025). SolStretch: Shiny App for Decorrelation Stretch of Raster Images (1.3.0). Zenodo. DOI: 🛠️ License: CC BY-NC 4.0 – Academic and personal use only