It’s fairly easy to blend two images in GIMP. All you have to do is: Open the two Images in GIMP. Blend the images using layer opacity/blend mode/layer mask. Export the resultant image as JPEG ...

Using GIMP, you can crop an image. rotate or flip a photo, Change dimension & scale of a picture, change the file size of a JPEG photo, etc.

Click GIMP's "File" heading and select the "Open" option from the menu that appears. Load the image that you wish to stretch, using the file explorer window. Click the "Image" heading.