What is com.apple.ImageConversionService?

I have been plagued by a horribly embarrassingly slow iMac since I purchased this one in 2013. Recently I started using it more and noticed how unbearably slow it really is. When starting up it is slow, opening any program is slow, and when I ran the activity monitor the com.apple.ImageConversionService is always at the top of CPU usage. What is this? What is it always running and eating up memory for? Google search left me with a lot of other forums full of questions but no answers. Help!