Description:The Image Statistics Module displays pixel statistics for the selected image.  


Image


This area displays information about the entire image


  • Mean: Displays the mean value (average) of all the pixel values within the image (ADU).
  • Median: Displays the median (middle) pixel value of the entire range.  The median is halfway between the brightest and darkest pixel (ADU).
  • Minimum: Displays the minimum pixel value (ADU).
  • Maximum: Displays the maximum pixel value (ADU).
  • Std Deviation: Displays the value of one standard deviation of the image (ADU).
  • Total Pixels: Displays the total number of pixels in the image.
  • Dimensions: Displays the pixel dimensions of the image (Width x Height)
  • Binning: If appropriate data is available, the binning of the image will be displayed here
  • Stars Found: Displays the total number of stars used for the Half Flux Radius calculation.  If the frame is not an Auto Focus frame or "Calculate HFR" has not been run on this image then "N/A" will be displayed.
  • Half Flux Radius: Displays the Half Flux Radius of the entire image.  The Half Flux Radius is a way to measure the relative size of a star.  This metric is useful for determining when an image is focused, the lower the value of this metric the better the focus.
  • Ideal Exp Time:  This metric is designed to display ideal exposure time for your current environment (camera and other atmospheric conditions).  In order to calculate this metric, you are required to enter data describing gain and readout characteristics of your camera).  This metric is based on the following study (http://www.hiddenloft.com/notes/SubExposures.pdf).


Notes on Ideal Exposure Time:


This value will be provided only for images that come directly off of the camera (it will not work for images opened off the disk) and requires 5 parameters to be of any use:


  • Integration time (automatic input from SGPro for the current camera image)
  • Mean background ADU (automatic input from SGPro for the current camera image)
  • Gain for the binning used in e-/ADU (user input from the camera tab in the control panel)
  • Readout noise in e- (user input from the camera tab in the control panel)
  • Percent contribution of read noise to total noise (assumed no more than 5%)


Sampling(21x21)


This area displays information about a 21x21 pixel sample centered at the cursor location


  • Mean: Displays the mean value (average) of all the pixel values within the sample (ADU).
  • Median: Displays the median (middle) pixel value of the sample.  The median is halfway between the brightest and darkest pixel (ADU).
  • Minimum: Displays the minimum pixel value (ADU) of the sample.
  • Maximum: Displays the maximum pixel value (ADU) of the sample.
  • Std Deviation: Displays the value of one standard deviation of the sample area (ADU).