How do I choose what to crop?

Enter the X and Y pixel coordinates of the crop rectangle's top-left corner and its width and height; the tool defaults these to the full uploaded image so you can adjust from there.

What happens if the crop rectangle extends past the image edge?

The tool rejects it with an error; the requested rectangle must lie entirely within the source stamp's bounds.

Does cropping affect image quality?

No, cropping simply copies the selected pixels directly with no resampling, so quality inside the cropped region is identical to the source.

Can I crop to a non-rectangular shape?

No, only rectangular crops are supported; for an irregular outline, key out the surrounding area with a background remover instead.

Stamp Cropper - Crop a Rectangular Region from a Stamp Image

Overview

Introduction

This tool crops a rectangular region out of a digital stamp image entirely in your browser, using exact pixel coordinates for precise control.

It's a direct pixel copy with no resampling, so the cropped result is exactly as sharp as the source.

What Is Stamp Cropper?

A client-side cropping tool that reads an uploaded stamp's pixel data and extracts the rectangle you define by its top-left corner and dimensions.

It's the same crop operation used throughout this category, applied to the stamp use case.

How Stamp Cropper Works

You specify X, Y, width, and height; the tool validates that this rectangle fits entirely within the source image's bounds.

It then copies each pixel inside that rectangle directly into a new, smaller output buffer, leaving colors and alpha completely untouched.

When To Use Stamp Cropper

Use it to isolate a single stamp from a photo containing multiple stamps or extra surrounding paper.

It's also useful for cutting a clean rectangular selection before applying a background-removal or recoloring pass.

Often used alongside Stamp Border Remover, Stamp Padding Remover and Stamp Resizer.

Features

Advantages

Runs entirely client-side; the uploaded stamp is never sent to a server.
Exact pixel-coordinate control for precise, repeatable crops.
No resampling means the cropped region is pixel-identical to the source.

Limitations

Only rectangular crop shapes are supported.
The crop rectangle must fit entirely within the source image; you can't crop with coordinates that extend past its edges.

Examples

Isolate a stamp from a wider scan

Input

A 1000x800 scan with a stamp at (200, 150), crop 300x300 from (200, 150)

Output

A 300x300 PNG containing just the stamp

Cropping removes the surrounding scanner bed and other content in one step.

Trim excess margin

Input

A 512x512 stamp PNG with a wide empty border, crop 400x400 from (56, 56)

Output

A tighter 400x400 PNG centered on the stamp's content

Manual coordinates let you trim precisely when the border isn't fully transparent.

Best Practices & Notes

Best Practices

Check the stamp's dimensions first with the PNG dimensions finder so your crop coordinates stay within bounds.
Crop before resizing so later dimension changes only affect the region you actually want.

Developer Notes

The rectangular-copy math lives in the shared png-cropper lib function; this tool's lib file thinly wraps cropPng rather than re-implementing the bounds-checked copy loop.

Stamp Cropper Use Cases

Extracting a single stamp from a multi-stamp scan sheet
Trimming a wide margin around a stamp before further editing
Cutting a stamp down to a specific aspect ratio before use

Common Mistakes

Entering a crop rectangle that extends past the image's actual dimensions, which the tool rejects.
Forgetting to reset the crop coordinates after uploading a new, differently-sized stamp.

Tips

If the border is fully transparent, the stamp padding remover can auto-trim it without needing manual coordinates.
Use the live preview to fine-tune coordinates before downloading.

Stamp Cropper