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Simple astronomical image analysis in mathematica
Distances
Projections
Summations over areas
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
Distances can be measured in many different ways using ImageJ
- Use the cursor and record the (x,y) coordinates of the two features you wish to measure
- Using the line too and make a projection
- Select the line tool
- Draw a line between the objects
- Analyze -> Plot profile
-
- Click either copy (to copy data to clip board for using in excel) or save to save a file of the 1-D data
- Using projetions (see below)
Projections
- To make a horizontal projection
- Select the rectangular region tool
- Select a region of the image
- Analyze -> Plot profile
-
- Again the profile data can be copied or saves
- 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