Difference: Photometry2016_StarFinder (1 vs. 2)

Revision 220 Oct 2016 - LauraBevilacqua

Line: 1 to 1
 
META TOPICPARENT name="StewartBoogertPhotometry2016"
-- LauraBevilacqua - 14 Oct 2016
Added:
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>
MEETING 1: 14/10/2016
 -Reverse grayscale as black dots easier to see on white background

-Pixel Values set from 0-max pixel value of the image

Line: 11 to 13
 
  • Dark Frame at 300s exposure:
    DarkFrame300max55000.jpg

  • Dark Frame at 300s exposure, maximum value set to the image median multiplied by 2: DarkFrame300maxmedian2.jpg
Changed:
<
<
-RGB coordinates used to define pixel colour so: black=(0,0,0), white=(255,255,255)
>
>
-RGB colour space used to define pixel colour so: black=(0,0,0), white=(255,255,255)
  -Fill function scans for black pixels and finds adjacent black pixels, fills them red
Line: 19 to 21
  -Function returns number of stars and coordinate of brightest pixel
Changed:
<
<
To do: -Program doesn't count fainter stars so need to determine min brightness for star, for now star count relies on brightest pixels so not accurate
>
>
MEETING 2: 21/10/2016

  • Fits files from Aaron converted to monochrome images

  • Image of single star
    FinderTest1a.jpg
  • The maximum pixel value was found to be 65195 from the fits file, as opposed to Aaron's given value of 65535
  • Threshold of 100 set so if pixels are above this value they are set as white background, if below they are coloured black (remember reverse grayscale)
    FinderTest1a_mon.jpg
  • Program locates star and returns count of 1
FinderTest1a_count.png
 
Changed:
<
<
-Find average star pixel value
>
>
  • Image of 8 stars
    FinderTest3.jpg
 
Changed:
<
<
-Could find star size and each individual brightness
>
>
  • Maximum pixel value found to be 62673, compared to Aaron's 60000
  • Threshold set as 20 so that stars don't touch, achieves accurate count of 8
    FinderTest3_mon.jpg
  • FinderTest3_count.png
 
META FILEATTACHMENT attachment="DarkFrame300max55000.jpg" attr="" comment="Dark Frame at 300s exposure" date="1476442670" name="DarkFrame300max55000.jpg" path="DarkFrame300max55000.jpg" size="54461" user="zyvb786" version="1"
META FILEATTACHMENT attachment="DarkFrame300maxmedian2.jpg" attr="" comment="Dark Frame at 300s exposure, maximum value set to the image median multiplied by 2" date="1476442711" name="DarkFrame300maxmedian2.jpg" path="DarkFrame300maxmedian2.jpg" size="59514" user="zyvb786" version="1"
Added:
>
>
META FILEATTACHMENT attachment="FinderTest1a.jpg" attr="" comment="" date="1476968368" name="FinderTest1a.jpg" path="FinderTest1a.jpg" size="6652" user="zyvb786" version="1"
META FILEATTACHMENT attachment="FinderTest1a_mon.jpg" attr="" comment="" date="1476968368" name="FinderTest1a_mon.jpg" path="FinderTest1a_mon.jpg" size="5525" user="zyvb786" version="1"
META FILEATTACHMENT attachment="FinderTest3.jpg" attr="" comment="" date="1476968368" name="FinderTest3.jpg" path="FinderTest3.jpg" size="14470" user="zyvb786" version="1"
META FILEATTACHMENT attachment="FinderTest3_mon.jpg" attr="" comment="" date="1476968368" name="FinderTest3_mon.jpg" path="FinderTest3_mon.jpg" size="6322" user="zyvb786" version="1"
META FILEATTACHMENT attachment="FinderTest1a_count.png" attr="" comment="" date="1476968784" name="FinderTest1a_count.png" path="FinderTest1a_count.png" size="13098" user="zyvb786" version="1"
META FILEATTACHMENT attachment="FinderTest3_count.png" attr="" comment="" date="1476971134" name="FinderTest3_count.png" path="FinderTest3_count.png" size="15887" user="zyvb786" version="1"

Revision 114 Oct 2016 - LauraBevilacqua

Line: 1 to 1
Added:
>
>
META TOPICPARENT name="StewartBoogertPhotometry2016"
-- LauraBevilacqua - 14 Oct 2016

-Reverse grayscale as black dots easier to see on white background

-Pixel Values set from 0-max pixel value of the image

-Bright pixels clearly seen

  • Dark Frame at 300s exposure:
    DarkFrame300max55000.jpg

  • Dark Frame at 300s exposure, maximum value set to the image median multiplied by 2: DarkFrame300maxmedian2.jpg
-RGB coordinates used to define pixel colour so: black=(0,0,0), white=(255,255,255)

-Fill function scans for black pixels and finds adjacent black pixels, fills them red

-Counting begins when black pixel is found

-Function returns number of stars and coordinate of brightest pixel

To do: -Program doesn't count fainter stars so need to determine min brightness for star, for now star count relies on brightest pixels so not accurate

-Find average star pixel value

-Could find star size and each individual brightness

META FILEATTACHMENT attachment="DarkFrame300max55000.jpg" attr="" comment="Dark Frame at 300s exposure" date="1476442670" name="DarkFrame300max55000.jpg" path="DarkFrame300max55000.jpg" size="54461" user="zyvb786" version="1"
META FILEATTACHMENT attachment="DarkFrame300maxmedian2.jpg" attr="" comment="Dark Frame at 300s exposure, maximum value set to the image median multiplied by 2" date="1476442711" name="DarkFrame300maxmedian2.jpg" path="DarkFrame300maxmedian2.jpg" size="59514" user="zyvb786" version="1"
 
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