# Photo Crop & Resize Planner

> Plan a precise crop and output size before resizing a photo. Calculate a centered crop, final pixel dimensions and scale for a target box. Fit keeps the whole image; fill crops to the requested aspect ratio. Upscaling is optional.

Part of usefulweb.app (https://usefulweb.app/). Results are deterministic calculations from the inputs and the listed assumptions; the API returns exactly what the web page shows.

## Use it
- Human interface: https://luminaresizeplanner.usefulweb.app/ (interactive tool at https://luminaresizeplanner.usefulweb.app/tool)
- JSON API: POST https://luminaresizeplanner.usefulweb.app/api/v1/calculate with a JSON object of inputs (schema: https://luminaresizeplanner.usefulweb.app/api/v1/tool)
- OpenAPI: https://luminaresizeplanner.usefulweb.app/openapi.json
- MCP (Streamable HTTP): https://luminaresizeplanner.usefulweb.app/mcp - tool `lumina_resize_planner`

## Inputs
- width (integer): Source width (px)
- height (integer): Source height (px)
- targetWidth (integer): Target width (px)
- targetHeight (integer): Target height (px)
- mode (select): Fit mode
- upscale (boolean): Allow enlargement

## Method
- Fit uses the smaller target/source scale; fill uses the larger one and a centered crop.
- When enlargement is disabled, scale is capped at 1. Pixel coordinates and output dimensions are rounded to whole pixels.