Hi there!
187 does seem quite high but it really comes down to the purpose of the pages. For some sites it might work, for others it won't. What type of website is it?
When doing a site / content audit I think it's important to understand what sort of value each page brings the user. You should consider looking at any analytics data you have for those pages to make a better judgement.
For example, if you find that the pages have a high bounce rate you might consider restructuring the pages or repurposing the image content for other areas of the website.
Hope this gets you thinking!