Our campus celebrates the tech-fest over the next 3 days, 17-19 March. Visit QUARK'07 website for more.

We are organising an Astronomy Workshop for participants, where I will present one talk. I am also involved with Image Processing contest, where students will be grilled for their skills with images.

## Friday, March 16, 2007

## Thursday, March 15, 2007

### Modified algorithm for UVIT frames

Make a table (dimentions 4x1000) for Poisson statistic. x-axis is average photons at a pixel P

For example: at x = P

For a given

For the next frame, compute a new random number R and repeat the above steps again...

_{ij}and Y-axis is the number of photons. X-axis values range from P_{ij}= 0.001, 0.002,... 1.000, in steps of 0.001 (1000 values). Y-axis has 4 values, which are equal to probabilities of number of photons incident = 0, 1, 2, 3.For example: at x = P

_{ij}= 0.1, the four values (corresponding to probability of 0, 1, 2, and 3 photons incident on that pixel) are P_{0}= e^{-0.1}(= 0.9048), P_{1}= 0.1 P_{0}(= 0.09048), P_{2}= 0.01 P_{0}/2 (=0.0045242), and P_{3}= 0.001 P_{0}/6 (= 0.0001508).For a given

**frame**, find a random number R_{k}**equally distributed between 0 and 1**. For each pixel- If R <>0, then number of photons for that pixel = 0.
- If (P
_{0}+ P_{1}) > R > P_{0}, then number of photons = 1; and if (P_{0}+P_{1}+P_{2}) > R > (P_{0}+P_{1}) then number of photons is 2; and so on.

For the next frame, compute a new random number R and repeat the above steps again...

## Monday, March 12, 2007

### UV image simulation from Galex

This is an algorithm to generate frames from Galex image.

You make a table (dimentions 4x1000) for Poisson statistic. x-axis is average photons at a pixel P

For example: at x = P

For a given

You make a table (dimentions 4x1000) for Poisson statistic. x-axis is average photons at a pixel P

_{ij}and Y-axis is the number of photons. X-axis values range from P_{ij}= 0.001, 0.002,... 1.000, in steps of 0.001 (1000 values). Y-axis has 4 values, which are equal to probabilities of number of photons incident = 1, 2, 3, 4.For example: at x = P

_{ij}= 0.1, the four values (corresponding to probability of 1,2,3 and 4 photons incident on that pixel) are 0.1, 0.035, 0.002, and 0.0005.For a given

**frame**, for each pixel_{k}- Find a random number R equally distributed between 0 and 1.
- If R > 0.1, then number of photons for that pixel = 0. If R > 0.035, 0.002 and 0.0005, then number of photons incident on that pixel are 1, 2, 3.

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