JPEG Image Binary File (HEX format) merging (QVGA / VGA)

Question

I need to generate a QVGA Image (320x 240) from RGB888. Due to memory constrain of the controller I have generated 3 JPEG images of (320 X 80). Now I need to merge these 3 (320 X 80) JPEG images to generate one complete QVGA JPEG image (320 x 240). I have Hex files for the 3 JPEG Images. Is there any C source file available to do other than OpenCV concept ???

What I have tried ?

1. Tried to Match the JPEG Header in the binary file : first half of the image is clear, remaining part is distorted.

What I'm expecting ?

1. C source file to merge the 3 or more JPEG Binary files to One.