Convert images to binary black-and-white using global threshold, adaptive threshold, Otsu, or advanced local methods (Niblack, Sauvola, Wolf, NICK). Essential for document binarization and object segmentation.
Segment images using global, adaptive, Otsu, Niblack, Sauvola, Wolf, and NICK thresholding.
All processing runs locally in your browser. Your files never leave your device — no upload, no server, no signup required.
Frequently Asked Questions
What is image thresholding?
Thresholding converts a grayscale image to binary (black and white) by comparing each pixel to a threshold value. Pixels above the threshold become white, below become black.
What is Otsu thresholding?
Otsu\
When should I use adaptive thresholding?
Adaptive thresholding is best for images with uneven lighting, shadows, or varying backgrounds. It calculates a different threshold for each local region of the image.
What are Niblack, Sauvola, Wolf, and NICK?
These are advanced local binarization methods from OpenCV ximgproc. They compute per-pixel thresholds using local mean and standard deviation. Sauvola and Wolf are generally better for document images. NICK works well with low-contrast text.