Integration and pixel scaling are enabling trends for low-cost, small form-factor, light-weight, and low-power camera systems across all optical frequency bands. Integration allows on-chip implementations of optical functionalities, e.g., polarization, color and spectral selectivity, which were previously achieved using bulky external components (e.g., prisms, filter wheels). Wavelength-size pixels require focusing and guiding of light at the pixel-level (e.g., micro-lenses, light guides), which was not necessary for larger pixels. On-chip integration of optical functionalities and pixel-level light control is often based on miniaturized versions of conventional optical components. These components derive their functionality from material properties or shapes, but do not lend themselves well to integration or scale to wavelengthsize pixels. Here, I present an overview of innovative integrated optical devices that overcome the problems associated with the integration and scaling of conventional components. They are enabled by scaling of imager and focal plane array technology, and by advanced nanofabrication. Wafer-scale processing and nanofabrication have made nano-scale patterning possible, while recent discoveries regarding the optical properties of nano-patterned structures have opened up important opportunities to develop ultra-compact photonic devices. I discuss design implementations for the visible (VIS) and infrared (IR) wavelength bands, including VIS integrated color pixels (ICPs) in a complementary metal-oxide semiconductor (CMOS) technology with geometry-based color filters, micro-lens functionality based on planar nanoaperture designs, and metal-based spectral filters for mid-wave IR (MWIR) multispectral imaging that can be implemented using standard nanofabrication methods. The devices are planar and/or ultra-thin, rely on processcompatible materials only, and derive their functionality from sub-wavelength geometry design.