Right now Symantec DLP is not supporting optical content recognition however few of other DLP providers have OCR support, being a consultant i have had this challenge at different customers who want to detect the leakage of confidential documents through image files.
If symantec is planning to have such integration it shouldn't be directly over the detection servers because it can impact the performance, a different server should be set up to meet this requirement and only image files should be forwarded to that server for OCR validation to check the policy compliance.
Regards,
Atif Shafique