To create an image with a transparent background, you can use the free software Gimp2 (an alternative to Photoshop) and follow one of the tutorials available online for making backgrounds transparent.
Keep in mind that .jpg files do not support transparency - you will need to save your file as either a .png or .webp format to maintain transparency.
In a blog post by Thomas Cokelaer from 2016:
Steps to achieve a transparent background:
- Open your image in Gimp2.
- Use the selection tool to choose the area you want to make transparent. You can utilize tools like magic wand/fuzzy select or Select regions by color for this process. Be sure to zoom in for accuracy when selecting.
- In the Layer menu, go to Transparency and select Add Alpha Channel if it's available. This enables transparency data storage for your image.
- Select Edit then Clear to make the selected area transparent.
- Save your file. When saving as a PNG, remember to check the 'Save colour values from transparent pixels' option in the Save As dialog box.
For more information, you can refer to these resources: