No, this is not something that we provide an option to change. Do you have a specific usecase that requires a larger texture, or would this be a 'nice to have' feature for you?
Also, in the future, http://forums.autodesk.com/t5/photo-on-recap360/bd-p/3019 would be a better place to ask questions like this one as this section is dedicated to the ReCap desktop product.
Thanks.
Basically, I want to take the models from Recap and bring them into a 3D modeling/animation program. My texture/lighting specialist has said that 4k textures probably wouldn't cut it. We were looking at Recap as an alternative to 123D Catch since we like the idea of being able to use more photos to get a potentially better mesh.
We have not purchased the subscription yet, as we wanted to get that question answered before we made a decision.