Store the image in variable

Hey everyone, I’m display the logos in my app in every page, & get the image from the url, put the url in one rootscope value and give the src as this rootscope value, here my problem is every time image loads. i’m trying to store the image into one variable Instead of save the url into rootscope . please help to how to store the image into variable and use the entire app without load every time .

Thanks in advance…