Difference: StewartBoogertTelescopeSimpleAnalysis (2 vs. 3)

Revision 318 Nov 2011 - StewartBoogert

Line: 1 to 1
META TOPICPARENT name="StewartBoogertTelescope"
PP Public TWikiUsers StewartBoogert StewartBoogertTelescope StewartBoogertTelescopeSimpleAnalysis

Simple astronomical image analysis in mathematica

Line: 15 to 17

Simple astronomical image analysis in ImageJ

ImageJ is a java based image analysis tool. It is mainly used for microscope image analysis, but can be useful for astronomical data analysis
  • Can install on your own personal computer (desktop/laptop). Download page
  • Installed on the teaching laboratory computers (All Programs -> Academic applications -> Physics -> ImageJ)

Getting started

  • Start ImageJ
    • Get small thin window
    • File -> Open -> Choose file (bmp or fits)
    • See a display of image
  • Things to note
    • Directly above the image see the image size and "bit depth"
    • Not all features are clear on the screen
    • Location of the cursor is given in pixel numbers on the main window


Distances can be measured in many different ways using ImageJ
  1. Use the cursor and record the (x,y) coordinates of the two features you wish to measure
  2. Using the line too and make a projection
    • Select the line tool
    • Draw a line between the objects
    • Analyze -> Plot profile
    • ImageJ_DistanceLineTool.jpg
    • Click either copy (to copy data to clip board for using in excel) or save to save a file of the 1-D data
  3. Using projetions (see below)


  1. To make a horizontal projection
    • Select the rectangular region tool
    • Select a region of the image
    • Analyze -> Plot profile
    • ImageJ_DistanceHorizontalProjection.jpg
    • Again the profile data can be copied or saves
  2. To make a vertical projection
    • First rotate the image (Image->Rotate)
    • Then make a profile as before

Summations over areas

Simple astronomical image analysis in python

META FILEATTACHMENT attachment="introToTelescope.nb" attr="h" comment="" date="1317981947" name="introToTelescope.nb" path="introToTelescope.nb" size="16071" stream="introToTelescope.nb" user="Public.StewartBoogert" version="1"
META FILEATTACHMENT attachment="ImageJ_LoadImage.jpg" attr="h" comment="" date="1321621958" name="ImageJ_LoadImage.jpg" path="Y:\ImageJ_LoadImage.jpg" size="194457" stream="Y:\ImageJ_LoadImage.jpg" user="Public.StewartBoogert" version="1"
META FILEATTACHMENT attachment="ImageJ_DistanceLineTool.jpg" attr="h" comment="" date="1321622495" name="ImageJ_DistanceLineTool.jpg" path="Y:\ImageJ_DistanceLineTool.jpg" size="212459" stream="Y:\ImageJ_DistanceLineTool.jpg" user="Public.StewartBoogert" version="1"
META FILEATTACHMENT attachment="ImageJ_DistanceHorizontalProjection.jpg" attr="h" comment="" date="1321622764" name="ImageJ_DistanceHorizontalProjection.jpg" path="Y:\ImageJ_DistanceHorizontalProjection.jpg" size="224122" stream="Y:\ImageJ_DistanceHorizontalProjection.jpg" user="Public.StewartBoogert" version="1"
META FILEATTACHMENT attachment="ImageJ_DistanceVerticalProjection.jpg" attr="h" comment="" date="1321623158" name="ImageJ_DistanceVerticalProjection.jpg" path="Y:\ImageJ_DistanceVerticalProjection.jpg" size="225876" stream="Y:\ImageJ_DistanceVerticalProjection.jpg" user="Public.StewartBoogert" version="1"
This site is powered by the TWiki collaboration platform Powered by PerlCopyright © 2008-2021 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding RHUL Physics Department TWiki? Send feedback