Piktochart is an easy to use web application that allows you to create visuals such as posters and infographics.
A general overview of Piktochart.
In this tutorial I go over some commonly asked questions such as how to insert and work with images (pictures and clip art) and, perhaps most importantly, how to download your project file.
1) Click your image to select it.
2) Press shift, and click a shape so that both the image and shape are selected.
3) Click the masking tool found at the top properties bar.
4) Double-click the masked image to resize or reposition the part of the image that shows in the shape or icon.
the above is pasted from https://support.piktochart.com/articles/235031268-how-do-i-crop-images-or-use-the-masking-tool