The problem of symbolic representation of gray value variations is studied, especially with respect to the gradient of the image function. The goal is to relate the results of this analysis to the structure of the picture, which is determined by the physics of the image generat ion process. The operators for the detection of gray value transitions are the first derivatives of two-dimensional Ga...

OBJECTIVE To evaluate prospectively the diagnostic accuracy of the thyroid imaging reporting and data system (TI-RADS) and its interobserver agreement and to estimate the reduction of indications of fine-needle aspiration biopsies (FNABs). DESIGN A prospective comparative study was designed. METHODS In 2 years, 4550 nodules in 3543 patients were prospectively scored using a flowchart and a ...

This paper proposed a new method of feature description for target recognition and matching. Firstly, a method of calculating the difference was defined. The gray value matrix of an image was converted to a difference value matrix. Then the difference value, shape, angle and other features of a region and the combined features between regions were described. Finally, the method was applied to i...

The number of bits assigned to represent the color intensity at image pixels is usually referred as the bit depth. When the bit depth is not sufficient, images suffer from ridge-like structures known as false contours. Bit-depth limitations become important when low-contrast details are required, as in medical imaging, aerial/satellite photography, and high-quality scanning applications. In thi...

OBJECTIVE Our aim was to figure out whether volumetric gray-scale histogram difference between anterior and posterior cervix can indicate the extent of cervical consistency. METHODS We collected data of 95 patients who were appropriate for vaginal delivery with 36th to 37th weeks of gestational age from September 2010 to October 2011 in the Department of Obstetrics and Gynecology, Korea Unive...

OBJECTIVE: To determine the role of transrectal ultrasound, especially in association with color Doppler, in the diagnosis of prostate cancer. MATERIALS AND METHODS: Eighty-four cases of patients who underwent transrectal biopsy were prospectively analyzed. In all patients, besides the traditional gray-scale sonogram, color Doppler study was performed in search of hypervascular foci. The result...

The choice and detailed design of structuring elements plays a pivotal role in the morphologic processing of images. A broad class of morphological operations can be expressed as an equivalent supremum of erosions by a minimal set of basis filters. Diverse morphological operations can then be expressed in a single, comparable framework. The set of basis filters are data-like structures, each fi...