In Astronomy, there will be often need to crop(cut) certain part of image. By using cropping technique, it becomes easy to highlight import part of the image, as shown in the below example, Red Giant Spot is cropped and then shown in another window (top right). Image credit -Nasa Jupiter Below is the python code used. When code is executed original image appears and then selected the part of the image which you want to cut. ****************************************************************** import cv2 import numpy as np # Read image image = cv2.imread("E:\\astronomy_related\\image_crop\\jupiter.jpg") # Select ROI r = cv2.selectROI("select the area", image) # Crop image cropped_image = image[int(r[1]):int(r[1]+r[3]), int(r[0]):int(r[0]+r[2])] # Display cropped image cv2.imshow("Cropped image", cropped_image) cv2.waitKey(0) ********************************************************* Credits code credit- https://www.geeksfo
There are various distances used to measure in Space/Astronomy. They are Mile, Kilometer, AU, Light year, Parsec. Mile and Kilometer - it is used for near by objects or Moon. AU(Astronomical Unit) -it is average distance between Sun & Earth. Probably used within solar system limits. Light year -Distance travelled by light in 1 year. It is used for larger distance beyond solar system. The distance between "Proxima Centauri" (the nearest star from earth) is 4.246 light years. Parsec - it is a unit of distance equal to 3.26 light-years. Cosmic distance ladder (extragalactic distance scale) - It is a technique of several methods used by Astronomers to determine the distance of cosmological bodies beyond our own galaxy, which are not easily determined using traditional methods. Learn more from below links- https://en.wikipedia.org/wiki/Cosmic_distance_ladder#Galactic_distance_indicators https://solarsystem.nasa.gov/news/1230/cosmic-distances/ https://en.wikipedia.org/wiki/As
In Astronomy, the image taken by telescopes of deep space field, galaxies, planets may appear to be complex - it may be difficult to find boundaries of objects when objects are too near. Or simply one would like to know the shape of the object. Edge detection technique is used in image processing for finding the boundaries of objects within the image. Edge detection would be very useful while analyzing such difficult images. Below is the sample image taken by James Webb telescope. Image Credits: NASA, ESA, CSA, STScI Below is grey image(left) and edge detection image(right) An edge detection operato r used in the above example is called as Canny edge detector Below is the python code used. ********************************************************************** import cv2 import numpy as np import matplotlib.pyplot as plt # read the image image = cv2.imread("E:\\astronomy_related\\edge_detection\\webb_first_deep_field.jpeg") # convert it to grayscale gray = cv2.cvtColor(ima
Comments
Post a Comment