Convert PNG to FITS

Understanding PNG and FITS file formats

PNG (Portable Network Graphics) is a widely used raster image format known for its lossless compression and support for transparency. It is commonly used for web graphics, digital photos, and images requiring high quality and transparency.

FITS (Flexible Image Transport System) is a digital file format primarily used in astronomy. It is designed to store, transmit, and manipulate scientific and astronomical data, including images and tables, with extensive metadata support.

Why convert PNG to FITS?

Converting a PNG image to FITS format is often necessary for scientific analysis, especially in astronomy, where FITS is the standard for image data. FITS files can store additional metadata and are compatible with specialized astronomical software.

How to convert PNG to FITS

To convert a PNG image to a FITS file, you need software that supports both formats. The most reliable and widely used tool for this purpose is SAOImageDS9 or Astropy (a Python library). Here’s how you can do it using Astropy:

1. Install Python and the required libraries:
   • Install Python from the official website.
   • Open your terminal or command prompt and run: pip install astropy pillow
2. Convert the PNG to FITS using a Python script:

   from PIL import Image
   import numpy as np
   from astropy.io import fits
   
   # Open the PNG image
   img = Image.open('input.png').convert('L')  # Convert to grayscale
   img_array = np.array(img)
   
   # Save as FITS
   hdu = fits.PrimaryHDU(img_array)
   hdu.writeto('output.fits', overwrite=True)
   

3. Check the output output.fits file in your working directory.

Best software for PNG to FITS conversion

• Astropy (Python library): Best for batch processing and automation.
• SAOImageDS9: Useful for visualization and manual conversion.
• GIMP (with FITS plugin): For users who prefer a graphical interface.

Summary

Converting PNG images to FITS format is essential for scientific and astronomical applications. Astropy provides a straightforward and reliable method for this conversion, ensuring compatibility with professional analysis tools.