ImageJ

ImageJ is a Java based image analysis program, it is mainly used for analysis of microscope images, not astronomical images. Click on the links below for a screen shot and simple instructions how to perform the operation.

• Open file
  Menu->File->Open
  
• Image info (FITS header information)
  Menu->Image->Show info
  

  FITS files contain lots of extra information which is very useful for image analysis, including number of pixels in x and y direction, cooler temperature, nbits, etc

  
• Adjust image
  Menu->Image->Adjust->Brightness/contrast
  

  Typically cameras can record significantly more ADU values than a screen can display. The BC window allows the use to change the maximum and minimum camera ADU which are displayed at 0 on screen and 255 on screen.

  

  Adjusting the maximum the fainter stars can be clearly seen

  
• Rectangle selection
  ToolBar->Rectangle
  

  Rectangular selection of image for analysis, click on the image to draw out the shape.

  
• Histogram of ADU (minimum, maximum, mean, variance)
  Menu->Analyze->Histogram
  

  Plots a histogram of the pixel ADU values in the selection (rectangle for example). The window shows simple statistical quantities for the pixels in the rectangle. The histogram data can be saved (icons at bottom at bottom of histogram window)

  
• Profile (horizontal projected profile)
  Menu->Analyze->Profile
  

  Profile makes a horizontal projection of the pixels in the selection. So it basically sums the pixel ADU in each column, to give the average ADC for that column. The data can be saved, in a similar way to the histogram.

  
• Rotated profile (Need to first rotate the image and then take horizontal profile)
  Menu->Image->Transform->Rotate 90 degrees right
  

  To take a vertical profile, i.e summing the row pixels in the selection region, the image has to be first rotated and then a profile made.

  
• Live horizontal line (Similar to MaximDL graph window horizontal line)

  Using the line selection tool, and the profile analysis, a section through the image can be generated. This by clicking on the live button at the bottom of profile window, it is possible to make a tool like the MaximDL graph window, which was used during observations to check for saturation etc.