We describe the imaging quality of the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) as measured during the ground calibration of the instrument. We describe the calibration techniques and report our results for the final configuration of HMI. We present the distortion, modulation transfer function, stray light, image shifts introduced by moving parts of th...

Cameras in mobile phones are supposed to capture images under a huge variety of lighting conditions while mostly hand held. To improve the performance in low light conditions, image stabilization shall optimize the resulting image by reducing the negative effects of motion blur due to handshake. While most cameras use an opto-mechanic approach and correct the motion by moving a lens element or ...

Helmholtz stereopsis has been previously introduced as a surface reconstruction technique that does not assume a model of surface reflectance. This technique relies on the use of multiple cameras and light sources, and it has been shown to be effective when the camera and source positions are known. Here, we take a stratified look at uncalibrated Helmholtz stereopsis. We derive a new photometri...

Relief mosaics are collections of registered images that extend traditional mosaics by supporting motion parallax. A simple parallax interpolation algorithm based on computed correspondence information allows high quality blurfree and ghost-free mosaics to be created using images from moving hand-held cameras that would not be suitable for traditional mosaicing. The renderer can also display lo...

We propose a technique to project a synthesized texture onto 3D textureless real objects without contact, which can be applied for example, in medical or archaeological applications. Our system uses two cameras and one projector. By projecting a suitable set of light patterns onto the surface of a 3D real object and by capturing images with one or several cameras, a large number of corresponden...

Imaging spectroscopy, the collection of hundreds of contiguous narrow-band images, offers an improvement over site-specific fiber optic reflectance measurements by combining both spatial and spectral information. We have focused on developing portable high sensitivity hyperspectral cameras capable to operate at low light levels, which is necessary for the examination of paintings, drawings, ill...

The theoretical wide-angle model of the human eye and the principle of separation of ophthalmoscopic illumination and observation apertures have been used to design two fundamentally different ophthalmoscopic cameras: a 90 degree wide-angle, noncontact camera and a high-resolution macula-disc camera. The chief advantage of the 90 degree noncontact camera is the increase in contrast achieved by ...

An optimum exposure control algorithm is necessary for any camera system to have a better image quality. Night vision requires the camera to make use of the ambient or illuminated IR light for a better image at low lighting conditions which is not desirable during day. A suitable IR cut filter algorithm should be combined with normal exposure control to have a better image quality without much ...

We present a reflective multiple-fold approach to visible imaging for high-resolution, large aperture cameras of significantly reduced thickness. This approach allows for reduced bulk and weight compared with large high-quality camera systems and improved resolution and light collection compared with miniature conventional cameras. An analysis of the properties of multiple-fold imagers is prese...