By setting Response header as Content-Disposition, We can send Image in REST Response
To Force Download Image
response.setHeader("Content-Disposition", "attachment; filename=\"sherlock_holmes.jpg\"")
To Display Image in Browser instead of Downloading
response.setHeader("Content-Disposition", "inline; filename=\"sherlock_holmes.jpg\"")
Note :
Image is placed inside src/main/resources/ folder & we used ClassPathResource to access the image
ClassPathResource imageFile = new ClassPathResource("holmes.jpg")