Radial Profile

Notebook name: radial_profile.ipynb

Description

This notebook allows you to display and export the radial profile of a set of images. Radial profile means that, after defining the center of your profile region, the closest pixel to the center will produces the first data point. Then the next ones will produces the second data point (average counts over the set of each pixels).

Confusing!

Well the following drawings should help you understand how that works.

Full circle

  • Step1: User defined the center of the profile (Red pixel in this example)
  • Step2: User defined the sector to use (in this case, we used the entire sector 0 -> 360degrees)
  • Program then calculate the position of each pixel relative to the new center defined
  • Program order the pixels by their distance relative to the center. All the pixels at the same distance from the center will have their counts averaged. Profile of Counts vs pixel index position is then calculated.

Sector

  • Step1: User defined the center of the profile (Red pixel in this example)
  • Step2: User defined the sector to use
  • Program keeps only the pixel that are within the sector defined
  • Program then calculate the position of each pixel relative to the new center defined
  • Program order the pixels by their distance relative to the center. All the pixels at the same distance from the center will have their counts averaged. Profile of Counts vs pixel index position is then calculated.

Start the notebook

If you need help accessing this notebook, check the How To > Start the python notebooks tutorial.

Select your IPTS

Need help using the IPTS selector?

Select Images to Process

Select the images you want to process using the File Selector. Once you click the Select button, the time stamp and the images will be automatically loaded. Wait for the progress bar to be done.

Need help using the File Selector?

Profile UI Presentation

After running the lauch User Interface cell, the following GUI pops up.

Selection of Sector Center

Using the mouse, click the vertical and then horizontal lines on the image window to define the center of the sector.

Selection of Sector Range

Grid Settings

It’s possible to change the settings of the grid (usefull when color of image and grid are too close).

Calculate Radial Profiles

Jump to the Profile tab and click the Calculate Profiles to calculate the radial profile of each image loaded. All those profiles will be displayed in the same plot below.

Export Profiles

Once the calculation of all profiles has been performed, the Export Profiles button becomes available. Click the Export Profiles … and select where you want to create the ascii files.

File Name Convention

The ASCII files creates will have the names bases such as

<name_of_image>_profile_c_x<x_center>_y<y_center>angle<from_angle_in_deg>to<to_angle_in_deg>.txt

where:

  • name_of_image: is the name of the source image without the extension (20170811_Nautical_compass_0030_356_250_1875)
  • x_center: the x axis position of the center (1024.0)
  • y_center: the y axis position of the center (1024.0)
  • from_angle_in_deg: starting sector angle in degrees (24.0)
  • to_angle_in_deg: ending sector angle in degrees (137.0)

giving a name of

20170811_Nautical_compass_0030_356_250_1875_profile_c_x1024.0_y1024.0_angle_24.0_to_137.0.txt

File Format

Each ASCII file produced start with the following metadata

# source image: /Volumes/my_book_thunderbolt_duo/IPTS/IPTS-19621-CLOCK/CT/20170811_Nautical_compass_0030_356_250_1875.tiff
# center [x0, y0]: [1024.0,1024.0]
# angular range from 24.0degrees to 137.0degrees

#pixel_from_center, Average_counts