I mentioned earlier that I found a way to process images completely online, so I did not have to install anything on my system to do it. I use free services to do this so you can do the same too. This post introduces you to the process and I’ll get into the details in subsequent posts (links at the end of this post).

First, here are the results:

  • Image 1 was processed online without any extra enhancements
  • Image 2 was also processed partially online and using free software installed on my system
  • Image 3 was processed completely offline using MaxIM DL and Photoshop

The source FITS files are from the MicroObservatory, a free online telescope service that I used to get started in remote imaging. You can download the source FITS files here if you want to try your hand at processing this image.

Note that the image is made up of just 3 minutes of observation time – one minute for each filter (R,G, and B). The nebula has a lot more detail in it but this result is really good considering the imaging time and conditions.

You can see from the result, that there is indeed an image of the Trifid nebula in image one. It is rather dark and I obtained this image by processing the source FITS files online using an online image editor. The editor allows you to apply a stretch function – I used log(x). The editor also allows you to combine RGB FITS to create the final color image (you have to align the images manually and color the images yourself too – I’ll explain how to do all of this).

I processed image 2 using the free FITS Liberator application to convert the FITS files into PNGs – I also applied a log(x) stretch to these images. I then used another online application to further bring out more detail and enhance the image. I also manually aligned, added color, and then combined the images for the final image. The details of how I processed this image are here: Using FITS Liberator To Create An RGB Image.

I processed image 3 using MaxIM DL and Photoshop. In MaxIM, I stacked and aligned, and then applied a DDP stretch (digital development), which is also a non-linear stretch except that its really good for astronomical images. I made some adjustments and then exported to TIFF format for import to Photoshop. In Photoshop, I used the Curves adjustment to enhance the contrast, and used a Vibrance adjustment to bring out the color. I also reduced noise by applying various processes and used a Gaussian blur on the entire image.

Let’s get into the toolset for basic processing of the image completely online. You don’t have to install anything, and you don’t have to sign up for anything too – you just use the online applications.

The first online application that I used to create image 1 is called JS9-4L image processor and it’s available at the MicroObservatory site – here’s the link: https://waps.cfa.harvard.edu/eduportal/js9/software.php. And this is the tutorial for how to use it: Image Processing Online – Part 1 – Using JS9-4L

The second online application I used, partly to create image 2, is called PhotoPea – a Photoshop clone that runs in your browser. Here’s the link to it: https://www.photopea.com/

I also used FITS Liberator to process image 2, just for comparison. You can get more details and download FITS Liberator here. The details of how I used FITS Liberator are here: Using FITS Liberator To Create An RGB Image.

I explain in detail how I created each image, and how to edit images in general, using these tools

  • Part 1 – Image Processing Online – Part 1 – Using JS9-4L
  • Part 2 – Image Processing – Part 2 – Enhancing a JS9-4L Image Using Photopea