DStretch Local Web Tool

Upload image(s) (gallery/files) ? Select one or many images from your gallery/files. New selection replaces the currently loaded source image(s).

On mobile, this picker can use gallery/files. Multi-select is supported for batch processing.

Take Picture ? Opens your phone to take a picture. Taking a new photo replaces previous pending selection.

Take Picture No file chosen

Stretch strength: 1.00 ? Controls how aggressively color differences are separated. Start near 1.0, then raise slowly until subtle features appear.

Clipping percentile: 1.00 ? Trims extreme pixel values so outliers do not dominate the result. Lower values are safer; higher values can look punchier.

Preserve mean color ? Keeps the overall color balance closer to the original image so enhancement remains realistic. Normalization mode ? Per channel balances each color channel independently. Global balances all channels together. None keeps raw stretched values.

Original

Art from Tassili n'Ajjer. Courtesy of Jacqueline Macou.

Processed

Process the image to preview enhanced output.

How This Program Works

This tool performs a DStretch-style decorrelation stretch, an image enhancement method that amplifies subtle color differences that are easy to miss in normal photos. It is especially useful for faint pigments, weathered inscriptions, corrosion patterns, mineral boundaries, and other low-contrast surface details.

Internally, the app analyzes RGB channel relationships, separates correlated color information, then stretches those separated components and maps the result back to a viewable image. In practice, this makes hidden or weak features stand out without manually painting or tracing the image.

Upload a clear image with good focus and lighting (or batch select multiple images).
Click Process / Apply once with default settings.
Increase Stretch strength gradually to reveal subtle structures.
Adjust Clipping percentile if highlights or shadows are too harsh.
Try Normalization mode options to compare color behavior.
Use preview zoom to inspect details, then download final outputs.