Difference: StewartBoogertPhotometry20161202 (4 vs. 5)

Revision 502 Dec 2016 - LauraBevilacqua

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META TOPICPARENT name="StewartBoogertPhotometry2016"
-- AaronAndrews - 01 Dec 2016
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  • LEFT: Median filter for M103. RIGHT: taylor series fit (25 terms, origin=(0,0))
  • M103_Median_65box.pngM103_Simtest_BGmean_2.png
  • Attempted to fit up to 100 terms - failed.
Added:
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Truncated Histogram:
  • Aim to make a mode filter over an image by defining a function that returned the mode of a truncated histogram
  • Stars populate the tail of the histogram with low frequencies --> set threshold frequency for mode filter as 1000/((1530*1020)/65^2) = 2
  • The mode is the pixel value with the highest frequency
  • Fit a gaussian to the truncated histogram, the mean of the gaussian corresponds to the mode of the truncated data
  • If there are not enough bins (less than 25), fit may not be executed, therefore we estimate the mode by finding the bin with the maximum frequency, return single value of mode
  • Run mode filter using output from truncation algorithm to obtain an array of modal pixel values
 
META FILEATTACHMENT attachment="Obs2_images_stacked.zip" attr="" comment="Observation2 - stacked images" date="1480585482" name="Obs2_images_stacked.zip" path="Obs2_images_stacked.zip" size="20631280" user="zyva010" version="1"
META FILEATTACHMENT attachment="DoubleCluster_200s_blue_5stack.png" attr="" comment="Double Cluster (blue) stacked" date="1480585984" name="DoubleCluster_200s_blue_5stack.png" path="DoubleCluster_200s_blue_5stack.png" size="1100020" user="zyva010" version="1"
 
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