Exact Crop for Lightroom Classic

Exact Crop is a small Lightroom Classic plug-in for applying the same exact pixel dimensions to one or more selected photos. It creates a centered crop using Lightroom's Develop settings and leaves the source files unchanged.

Features

• Crop one or more selected photos to a requested width and height in pixels.
• Center the crop automatically on each photo.
• Validate the requested dimensions before applying the crop.
• Apply the crop as a Lightroom catalog edit, so it remains non-destructive.

Requirements

• Adobe Lightroom Classic with plug-in support.
• Photos must be selected in the active catalog.

Installation

1. Download or clone this repository.
2. In Lightroom Classic, open File > Plug-in Manager.
3. Click Add and select the directory containing Info.lua and ExactCrop.lua.
4. Confirm that the plug-in is enabled in Plug-in Manager.

Keep the two Lua files together. Lightroom loads the plug-in directly from this directory, so move or rename it only after removing and adding it again in Plug-in Manager.

Usage

1. Select one or more photos in Lightroom Classic.
2. Open File > Plug-in Extras > Crop.
3. Enter the target Width and Height in pixels.
4. Click OK.

The plug-in applies a centered crop to every selected photo and reports how many photos were updated.

Batch behavior

When multiple photos are selected, the requested width cannot exceed the smallest selected photo width, and the requested height cannot exceed the smallest selected photo height. This lets the same dimensions be applied to the whole selection.

The crop is centered independently on each photo. Existing crop position and crop angle are replaced; the crop angle is reset to zero.

Limitations

• The plug-in crops photos; it does not resize or export them.
• The requested dimensions must be positive whole-number pixel dimensions.
• The target dimensions must fit within every selected photo.
• The current implementation uses the photo dimensions reported by Lightroom and assumes those dimensions are available for each selected photo.
• There is no built-in undo or preview step beyond Lightroom's normal catalog history and undo behavior.

Development

The plug-in is implemented in Lua using the Lightroom Classic SDK:

• Info.lua declares the plug-in and registers its menu command.
• ExactCrop.lua displays the dialog, validates the input, and applies the Develop crop settings.

No third-party dependencies or build step are required.

License

This project is licensed under the GNU General Public License, version 3. See LICENSE for the full text.