Actually, this is probably because DVCPROHD works at 960x720, while the HD100 images you linked to are at the 1280x720 HD format size. DVCPROHD images need to be stretched(up-rezzed) from 960x720 to 1280x720.
Likewise with DVCPROHD 1080P material, it is recorded at 1440x1080, and needs to be stretched to 1920x1080.
Likewise with DVCPROHD 1080P material, it is recorded at 1440x1080, and needs to be stretched to 1920x1080.