These instructions are based on using Adobe Photoshop CC, which is available for university Faculty and Staff.
Cropping and Resizing
Crop your photo by first clicking on the Crop icon. Make sure it is set to crop by Ratio and then put in the ratio at which you'd like to crop the photo (ex: 1600 px x 900 px).
Drag the image to select where you'd like it to be cropped at this ratio. Check the checkmark to confirm the crop.
In the menu, go to Image and select Image Size.
Set the resolution to 72. Enter the size you'd like to crop the photo to (see our guide to sizing), and make sure resample is set to Bilinear.
Optimizing and Saving for Web
Next you'll need to save your resized and/or cropped photo and optimize it for the web.
In the menu, go to File and click Save for Web. (In newer versions, this has moved under File > Export > Save for Web.)
Make sure that it will save as a JPEG and at the top of the box where it says Quality, set it to 80 and using the scroll bar, look under the image in the bottom left corner and as you scroll it lower try to get it as close to 300K as possible (try for no lower than 50).
Click Save and then save it to your computer.
Now you are ready to upload it to your SharePoint site's images library.