The phrase "an appropriate image" is correct and usable in written English.
You can use it when referring to an image that is suitable or fitting for a particular context or purpose.
Example: "For the presentation, we need to select an appropriate image that illustrates our main point effectively."
Alternatives: "a suitable image" or "a fitting image".
It seems an appropriate image in the circumstances.
"Each culture had different ideas about what is an appropriate image to photograph," Ms. Cohen said.
Connect these circles, in the order of the sequence, to form an appropriate image".
You may choose a religious image as long as you feel you can justify the reason it is an appropriate image to appear in this location.
What is an appropriate image of youth when pubescent 13-year-olds already look the way 27-year-old sexpots did a generation ago?
That frozen timepiece is an appropriate image for a poet whose best work seems to still time, to suspend a moment of clear-sighted observation.
pS6 immunoreactivity within the dorsal column was quantified using an appropriate image-processing program (FIJI, available at http://fiji.sc/About).sc/About
Each large canvas features an appropriated image of a woman distorted, as though by a funhouse mirror or a digital program, into an almost illegible spiral.
She describes the work as "an appropriated image from Cara Delevingne´s Instagram account that she posted the day her and Jourdan Dunn got matching DD tattoos (after their lasts names)." Their tattoo is the same as the Ds in Delmar's logo, which is also coincidentally the same logo as an LA-based plastic surgeon.
It was the proof that there could, in fact, not only be a compositionally perfect moment in time, but also a precisely appropriate image to tell a particular story.
Furthermore, 'seas of under provision' sound like depths that will never be filled, while in fact it would take relatively modest resources (on a global scale) to fill them; 'swamps' might be a more appropriate image.
