Upload image and display same time

hi i want to display image as it is uploaded,

–> i have a render partial form in which i used iframe like this,

Select Image:

where image is uploaded, for that on click of update button in editImage
i am calling Update method which stores image path in database. and it
done perfectly.

but i want to display the latest image which is stored in database, but
sometimes it is giving ang sometimes it just gives path.

any other way to do it? i search a lot but mostly are giving rmagick
sollution …
cant it done without rmagick? if it can then plz tell.

thanks in advance…