Pix4Dmapper Mesh supports the highest image resolution that can be captured by the GoPro 4. Do you have 12 MP images that you can process for your project? If not, is it possible to capture images using the highest resolution available with your GoPro Hero 4?
Please note that the other image options and video files capture formats captured by the GoPro produce lower resolution frames than the 12 MP image option. Thus the 12 MP image option provides Pix4Dmapper with the highest level of image content available with this camera.
You can find a complete list of the file formats and cameras supported by Pix4Dmapper Mesh at https://support.pix4d.com/hc/en-us/articles/207333833.