Noise reduction filters

The Median, Blur, Despeckle, and Smooth filters remove noise and detail by averaging the colors of adjacent pixels in the image. You may set the size of noise details should be removed by using Radius parameter. Range parameter lets to keep image edges untouched, while smooth small details that affect compression.

Image on Fig.1 has the same JPEG compression parameters as one on Fig.2, but prefiltering makes it more compressible without losing important image details

Fig.1 JPEG with
Median filtering
File Size 7.5 KB

Fig.2 JPEG without filtering
File Size 8.5 KB

Sharpen filter

The Sharpen filter accentuates the edges in the image by finding the edges and increasing the contrast between adjacent pixels.

By default sharpening applied for Lightnes color channel only, to avoid halo artifacts and to minimize file size increasing. Parameter Threshold lets you minimize noise amplification in the non edge areas.

Image on Fig.1 has the same JPEG compression parameters as one on Fig.2. It was selectively sharpened that almost not affected image file size.

Fig.3 JPEG with Sharpen filtering
File Size 8.6 KB

Fig.4 JPEG without filtering
File Size 8.5 KB