in this study, we used monthly palmer severity drought index (pdsi) data of national center of oceanic atmospheric administration (noaa) during 1/1950 to 12/2005(56 year). the time and space resolution of data is monthly and 2.5*2.5 degree respectively. therefore 26 pixels located in iran political boundary. a matrix 26*672 carried out that pixels located on rows and month located on column. th...

A color image edge detection algorithm is proposed in this paper using Pseudo-complement and matrix rotation operations. First, pseudo-complement method is applied on the image for each channel. Then, matrix operations are applied on the output image of the first stage. Dominant pixels are obtained by image differencing between the pseudo-complement image and the matrix operated image. Median f...

An imaging system includes an array of lenses, a plurality of sensor pixels for each lens, the sensor pixels being on an image plane of the imaging system, and a corresponding plurality of focal plane coding elements. A focal plane coding element for each sensor pixel has multiple sub-pixel resolution elements. The focal plane coding element being between the lens and each sensor pixel, wherein...

Introduction: The limited resolution of the imaging system causes partial volume effects (PVEs). These results in spreading of image counts to the neighboring pixels. This phenomenon is called spill-out effect. This study aimed at quantifying PVEs using ImageJ. Methods:Technetium-99m solution of concentration of 74 kBq/ml was filled into spheres A, B<...

In this paper, an approach for the reduction of unwanted edges in contour detection based on local filtering is presented. Our can be used as a preprocessing step before detection. Also our useful object recognition feature extraction tasks, because many methods can’t delete all carefully. method consists computational algorithm that has 7 steps. Including smoothing, edge detection, decreasing ...

We designed 4x4 matrix TFTs arrays using current mirror amplifiers. Advantages of current mirror amplifiers are they need less requiring switches and the conversion time is short. The TFTs arrays 4x4 matrix using current mirror circuits have been fabricated and tested with success. The TFTs array directly can process signals coming from 16 pixels in the same node. This enables us to make the su...

introduction: ordered subset expectation maximization (osem), is an effective iterative method for spect image reconstruction. the aim of this study is the evaluation of the role of system matrix in osem image reconstruction method using four different physical beam radiation models with three detection configurations. methods: spect was done with an arc of 180 degree in 32 projections after i...