Map Getting on Low Res when i change maps or Refresh

Hello, I have a map of the world of my campaign in a large image of 13 mb and a grid of 55 width to 100 height. When i load the image of the map all works fine and in high resolution, but if i refresh the page or change maps and change back, the image transforms in a low resolution version. What can i do? Thanks in advance.

Hi francisco! Really large maps do better if  they are uploaded in pieces and re-assembled in Roll20. With that many grid squares I would recommend it. In the meantime, you can usually force the engine to load the hi-res copy by zooming all the way out and then back in. My theory it has something to do with forcing Roll20 to use the thumbnail version and then subsequently switch to the original version. Every graphic you upload gets processed into four different resolutions, to facilitate better performance as you zoom in and out and pan around. This is usually invisible to the user, and does not affect your storage quota (only the original uploaded version does that). But for best results, I would suggest slicing the image up into 2-4 pieces if you are able to do so.

Thank you Keith, spliting the image in four worked like a glove. Thank you very much sir!