To make an image transparent in PowerPoint, you have to change the opacity of the image - and you can do it for the whole image or a part.

You can make a picture transparent in your PowerPoint slides so that you can add text over it or use it as a background.

You can make your image or photo in PowerPoint transparent, have the background removed, or have a combination of color and grayscale.

After making the image a bit transparent, you’re ready to add the lines that create the collage effect. How to insert lines to create a collage effect in PowerPoint ...

To add alt text to images in PowerPoint, or edit an image's existing alt text, select the photo and choose "Edit Alt Text." ...