Image Sharpener

Image sharpening is a digital image processing technique that enhances the contrast along edges and fine details in a photograph or graphic. When an image is captured, compressed, or resized, edges can become slightly blurred — sharpening restores the perceived crispness by amplifying the difference between adjacent pixels at boundaries. Our image sharpener implements two professional-grade algorithms — Unsharp Mask and Laplacian — entirely in your browser using pixel-level canvas processing, with no server upload required.

1. 1. Upload Your Image: Drop or select any PNG, JPG, WebP, GIF, BMP, or TIFF file. The image is loaded directly into your browser — nothing is sent to a server.
2. 2. Configure Sharpening Settings: Choose Unsharp Mask or Laplacian, then adjust the strength, radius, and threshold sliders. The settings summary updates in real time so you always know what will be applied.
3. 3. Download the Result: Click Sharpen Image to process the file locally using canvas convolution. Preview the before and after side by side, then download as PNG, JPG, or WebP.

• Edge Contrast: Pixel differences at boundaries are amplified, making edges appear crisper and more defined.
• Fine Detail: Textures and small features that were softened by compression or resizing are restored to their original perceived sharpness.
• Smooth Areas: With Unsharp Mask, the threshold parameter protects smooth gradients and skies from being sharpened, preventing noise amplification.
• File Size: Sharpened images typically have slightly larger file sizes than the original because increased edge contrast reduces compressibility.

Unsharp Mask works by subtracting a blurred copy of the image from the original and adding the difference back scaled by the amount parameter. The radius controls how wide the blur is (and therefore how broad the sharpened edges are), while the threshold prevents sharpening in areas where the difference is too small to be a real edge. This produces natural-looking results and is the standard technique used in Photoshop, Lightroom, and professional print workflows. Laplacian sharpening applies a 4-connected edge-detection kernel directly to the image and adds the response back. It produces a crisper, more aggressive effect that works well for text, line art, and high-contrast subjects, but can amplify noise in smooth photographic areas.