How to show progress until all the images from spreadsheet doesn't fully loaded or displayed

I want to show progress until my all images from spreadsheet not loaded on dynamic image view . Something like this :-
images (12)
Look of my app is:

And my code of app is :-

If you does not want to invisible the progress bar then there is no need to use image utility to load images it will take time but the progress bar visible till all the images load

Use the image loader extension available in the community than you can use the Image Loaded event and if it was the last image than set visibility and so on.