Thumb Resizer for IBPS

Purpose & User Intent: The tool solves the need to produce uniform image thumbnails for IBPS study materials. Primary users include exam-content teams, tutors, and students assembling practice sheets, PDFs, slides, and online repositories. It is used when consistent thumbnail dimensions and predictable output are required, minimizing manual edits and rework. The tool supports single-image and batch resizing within a single session, with non-destructive previews and format-safe outputs.\n\nCore Logic & Features: Domain rules govern input validation, dimension handling, and output encoding. Required features: image input (JPEG/PNG), target_width_px, target_height_px, and an option to lock aspect ratio. Outputs must reflect the final dimensions and file size. Optional/advanced features: batch mode across multiple files, choice of output format (PNG/JPEG/WEBP), compression quality, and optional metadata stripping. In all cases, no cropping or color grading is performed unless requested; resizing avoids unintended stretching when aspect ratio is locked.\n\nInputs & Outputs: Inputs include source_image (file, types: JPEG/PNG, required), target_width_px (int, px, sample 300, required), target_height_px (int, px, sample 250, required), maintain_aspect_ratio (bool, default true, optional), output_format (string, options: PNG/JPEG/WEBP, optional), quality (0–100, optional), batch_mode (bool, optional). Outputs include resized_image (file, same/smaller size), final_dimensions_px (width x height), estimated_file_size_kb, and per-output quality metrics if available.\n\nAlgorithms & Calculations: When maintain_aspect_ratio is true and only one dimension is provided, the missing dimension is computed from the original aspect ratio. If both dimensions are provided with locking enabled, the tool preserves the closest valid ratio. Resampling uses bicubic/Lanczos-like filters with anti-aliasing. Outputs are encoded per selected format with the chosen quality; transparency is preserved for PNG/WEBP where supported.\n\nError & Edge Cases: Invalid or missing inputs trigger domain errors (e.g., non-image files, negative dimensions, zero values). Large inputs may require pre-scanning or queuing. Unsupported formats, unsupported output combinations, or conflicting settings produce explicit, actionable error codes and messages (no UI messaging in the tool layer).\n\nIndustry/Region & Localization: Units are pixels; no currency. For IBPS practice materials, outputs should align with standard A4/letter layout when embedded in documents; language handling follows en-us conventions for metadata and filenames. Localization considerations are limited to filenames and comments.\n\nAssumptions & Exclusions: Assumes a valid source image is supplied and that the user understands pixel-based sizing. Excludes cropping, watermarking, color correction, or batch scheduling beyond a single workflow; does not perform content-aware resizing.