Spatial Frequencies

Spatial Frequency - Visual Perception - Spatial-frequency Theory
... The spatial-frequency theory refers to the theory that the visual cortex operates on a code of spatial frequency, not on the code of straight edges and lines hypothesised by Hubel ... particular angle in a particular location in the visual field The spatial-frequency theory of vision is based on two physical principles Any visual ... in each module are thought to respond selectively to various orientations and frequencies of sine wave gratings ...

Subpixel Rendering - Addressability Vs. Resolution
... the addressability allows the font designer to use spatial frequencies and phases that would have created noticeable distortions had it been whole pixel rendered ... points on the display this does not always mean that higher resolution, higher spatial frequencies, more lines and spaces, may be displayed on a given arrangement of colour subpixels ... A phenomenon occurs as the spatial frequency is increased past the whole pixel Nyquist limit from the Nyquist–Shannon sampling theorem Chromatic aliasing (colour fringes) may ...

Holography - Recording A Hologram - Holographic Recording Media
... spatial frequencies ranging from a few hundred to several thousand cycles/mm, and ideally, the recording medium should have a response which is flat over this range ... If the response of the medium to these spatial frequencies is low, the diffraction efficiency of the hologram will be poor, and a dim image will be obtained ... very low, or even zero, response at the frequencies involved and cannot be used to make a hologram - see, for example, Kodak's professional black and white film whose ...

Transmission Electron Microscopy - Limitations - Resolution Limits
... in the frequency domain to define the reproduction of spatial frequencies of objects in the object plane by the microscope optics ... This oscillatory nature implies that some spatial frequencies are faithfully imaged by the microscope, whilst others are suppressed ... By combining multiple images with different spatial frequencies, the use of techniques such as focal series reconstruction can be used to improve the ...