The pixel-value differencing (PVD) steganography can embed a large amount of secret bits into a still image with high imperceptibility as it makes use of the characteristics of human vision sensitivity. However, a loophole exists in the PVD method. Unusual steps in the histogram of pixel differences reveal the presence of a secret message. An analyst can even estimate the length of hidden bits ...

Stimulus response latency is the delay between stimulus onset and the evoked modulation in neural activity. A common technique to estimate latencies involves binning the spike arrival times to form a peri-stimulus histogram. This histogram is smoothed using a fixed bandwidth. The estimated latency is the first time following stimulus onset in which the smoothed histogram exceeds the midpoint be...

Background: The aim of this study was to investigate the ability of three-dimensional (3D) ultrasonography and anti-Mullerian hormone (AMH) to predict successful embryo development in patients undergoing in vitro fertilization (IVF) treatment. Materials and Methods: We prospectively studied 28 patients undergoing IVF treatment, using 3D ultrasound Sono automatic volume calculation (AVC) and a 3...

We develop reconfigurable mesh (RMESH) algorithms for window broadcasting, data shifts, and consecutive sum. These are then used to develop efficient algorithms to compute the histogram of an image and to perform histogram modification. The histogram of an N×N image is computed by an N×N RMESH in O (√ B log√ B (N/√ B ) for B < N, Ο(√ N ) for B = N, and Ο(√ B ) for B > N. B is the number of gray...

Histogram equalization (HE) is widely used for contrast enhancement. However, it tends to change the brightness of an image and hence, not suitable for consumer electronic products, where preserving the original brightness is essential to avoid annoying artifacts. Bi-histogram equalization (BBHE) has been proposed and analyzed mathematically that it can preserve the original brightness to a cer...

Selecting a threshold from the gradient histogram, a histogram of gradient magnitudes, of an image plays a crucial role in a gradient based edge detection system. This paper presents a methodology to determine the threshold from a gradient histogram generated using any kind of linear gradient operator on an image. We consider the image as a random process with dependent samples, model the gradi...

Contemporary datasets are becoming increasingly larger and more complex, while techniques to analyse them are becoming more and more inadequate. Thus, new methods are needed to handle these new types of data. This study introduces methods to cluster histogram-valued data. However, histogram-valued data are difficult to handle computationally because observations typically have a different numbe...

We consider the following image processing problems: compute the area and perimeter of the components of an image, compute the histogram of an image, and histogram modification. Parallel reconfigurable mesh computer algorithms are developed for these problems. The area and perimeter of the components of an N×N image are computed in O (logN) time by an N×N RMESH; the histogram of an N×N image is...

Histogram equalization is often used in image enhancement, but it can be also used in auto exposure. However, conventional histogram equalization does not work well when many pixels are concentrated in a narrow luminance range. This paper proposes an auto exposure method based on 2-way histogram equalization. Two cumulative distribution functions are used, where one is from dark to bright and t...