Batch Photo Watermark Adder (Local Processing)

Overview

This application is a privacy-first, client-side web utility designed to allow users to apply text or image-based watermarks to large batches of photographs without uploading files to a server. All image manipulation is performed locally using the HTML5 Canvas API.

Core Features

• Drag-and-Drop Uploader: Support for bulk uploading images via drag-and-drop or file system picker.
• Real-time Preview: Interactive preview mode to visualize how the watermark will look on individual images.
• Flexible Watermarking:
  • Text Watermark: Customizable font, font size, color, opacity, rotation, and alignment.
  • Logo Watermark: Support for PNG/SVG logo uploads with scaling and tiling options.
• Processing Engine: Uses Web Workers to prevent UI freezing during heavy image processing tasks.
• Batch Export: One-click download of all processed images as a single, compressed ZIP file.
• Preservation Options: Toggles to maintain or strip EXIF metadata.

Layout Structure

• Header: Simple, clean navigation with instructions toggle.
• Main Dashboard (Two-Column Layout):
  • Left Sidebar (Configuration Panel): Contains settings for watermarking, including tabs for 'Text', 'Image', 'Position', and 'Output Settings'.
  • Right Canvas (Workspace): Displays the list of queued images with status indicators (Pending, Processing, Done). Includes a focused preview window for selected images.
• Footer: Status bar indicating memory usage and processing progress.

UI/UX Design

• Visual Style: Minimalist aesthetic. High contrast, using a palette of Slate Grey, Cool White, and Indigo for primary actions.
• Animations: Subtle transition effects when files are added to the list. Smooth progress bars for the batch processing state.
• Feedback: Clear success/error state icons for individual file processing.

Technical Implementation

• Frontend: HTML5, CSS3 (using Flexbox/Grid for responsiveness), and JavaScript (ES6+).
• Performance:
  • OffscreenCanvas API for non-blocking rendering.
  • JSZip library for creating downloadable archives in-browser.
• Accessibility: Fully keyboard-navigable interface and screen-reader compliant input labels.
• Browser Compatibility: Works on all modern Chromium and WebKit-based browsers.