Wavelet techniques have become an attractive and eecient tool in function estimation. Given noisy data, its discrete wavelet transform is an estimator of the wavelet coeecients. It has been shown by Donoho and Johnstone (1994) that thresholding the estimated coeecients and then reconstructing an estimated function reduces the expected risk close to the possible minimum. They ooered a global thr...

Rendering document images for scanning and printing applications typically involves binarization via adaptive thresholding, halftoning, or color dropout. While bitonal rendering is often adequate, there are cases where multi-level rendering is required to capture important image characteristics. In this paper, we present two methods for multilevel rendering of document images. The first method ...

When using thresholding method to segment an image, a fixed threshold is not suitable if the background is uneven. Here, we propose a new adaptive thresholding method using variational theory. The method requires only one parameter to be selected and the adaptive threshold surface can be found automatically from the original image.

Image thresholding is a common task in many computer vision and graphics applications. The goal of thresholding an image is to classify pixels as either “dark” or “light”. Adaptive thresholding is a form of thresholding that takes into account spatial variations in illumination. We present a technique for real-time adaptive thresholding using the integral image of the input. Our technique is an...

An adaptive local thresholding method for microscope based high content analysis (HCA) is proposed. Cell micrographs of HCA contain detailed objects both in and out of focus, which cannot be correctly segmented by global thresholding methods. The proposed method utilizes adaptive local neighborhood size and double thresholding, and is able to produce segmentations that conform closely to percep...

Two algorithms for document image thresholding are presented, that are suitable for scanning document images at high-speed. They are designed to operate on a portion of the image while scanning the document, thus, they fit a pipeline architecture and lend themselves to real-time implementation. The first algorithm is based on adaptive thresholding and uses local edge information to switch betwe...