Need sample javascript application for uploaded file

Hi all, I need sample javascipt application for uploaded file base64 data. I want to split large file into small small bytes and finally merge that base64 data and display into image tag. File upload must be image. For example i have uploaded 10kb image file. Image should be split 0 to 5kb and 5kb to 10kb. generated base64 data should be store into array and merge data and display merged base 64 data into image tag like orginal file i need to display. merged data to be like orginal base64 data for preview. More details will be provided.