Hi,
Please use innerpage banner image to solve this issue
To change inner page banner image: Go to Appearance » Theme Options » Homepage Slider » Inner Page Banner
To set different banner image for each individual page
– Edit that page and set Featured Image
– Default image size for inner page banner image is 1400 x 350 pixels
Please check the documentation
http://www.gracethemesdemo.com/documentation/travel-trip/#innerpage-banner
Regards
Grace Themes