We present a new checkerboard detection algorithm which is able to detect checkerboards at extreme poses, or checkerboards which are highly distorted due to lens distortion even on low-resolution images. On the detected pattern we apply a surface fitting based subpixel refinement specifically tailored for checkerboard X-junctions. Finally, we investigate how the accuracy of a checkerboard detec...

In an inhomogeneous checkerboard surround, the lighter check darkens an incremental test patch more than the darker check lightens it. However, decremental test patches are influenced equally [Schirillo & Shevell, 1996. Vision Research, 36, 1783-1796]. In the current study, we manipulate the spatial arrangement of a checkerboard surround to produce T-junctions that perceptually group the checks...

Two different synergy testing methods, the checkerboard and the E test methods, were used to compare the in vitro efficacies of various antimicrobial combinations against 16 Brucella melitensis strains isolated from blood cultures. The rate of agreement of the E test and checkerboard methods was found to be 55%. The most concordant results were found for the streptomycin-doxycycline combination...

The checkerboard extraction process is an important pre-preprocessing step in camera calibration. This project attempts to implement the checkerboard extraction processes using methods learned from EE368. This includes the isolation of the checkerboard using morphological operations. The benefit of the approach is that it is efficient since morphological operations can be implemented efficientl...

We performed high-resolution scanning tunneling microscopy/spectroscopy on an optimally-doped Ca2 xNaxCuO2Cl2 crystal with Tc 25 K. The so-called ‘‘checkerboard’’ local-density-of-state modulation previously found in heavily underdoped regime also manifests in the spectroscopic map of the optimally-doped sample. In addition, spatially-inhomogeneous energy gap with peaks at the gap edges is obse...

It is believed that human primary visual cortex (V1) increases activity with increasing temporal frequency of a visual stimulus. Two kinds of visual stimulus were used in the previous studies, one is patterned-flash stimulus with a fixed onset period and an increasing average luminance with the increase of temporal frequency, the other is contrast reversing flickering checkerboard or grating wi...

CHECKERBOARD codes are two-dimensional binary codes that are designed to satisfy specific constraints [1], [2]. An example is the two-dimensional rectangular binary arrays that satisfy the (d, k) run-length constraint— there are at most k 0’s and the number of 0’s between any neighboring 1’s is at least d in each row and column [3]–[7]. It may naturally arise from data storage on a surface [8],...

A peculiar cellular pattern resembling a checkerboard has been observed on the luminal surface of the oviduct epithelium of an adult Japanese quail. The epithelium is a monolayer cell sheet and consists of two types of columnar cells, ciliated cells (C-cells) and gland cells (G-cells) assembled in alternating blocks. The pattern develops, during sexual maturation, from a kagome-like pattern (in...

for n ≥ 2, it can be shown that fn counts the number of ways to tile a 1 × n board with squares and dominoes. This interpretation of the Fibonacci numbers admits clever counting proofs of many Fibonacci identities. When we consider more complex combinatorial objects, we find that simply counting the number of tilings is not quite enough, and that we must consider instead weighted tilings. For e...