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Pointspread
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Pointspread A measure of optical blur produced by natural imperfections of the lens of the eye. The response to a point of light produces a certain amount of blur, the amount of this blurring is known as the pointspread.
RELATED TERMS--------------------------------------
Optical
Having to do with vision.
Natural
Not human-induced or manmade.
Lens
The lens of the eye is like an adjustable lens of a camera and focuses light rays on to the retina for sharp images. A condition called presbyopia occurs when the lens is no longer able to adjust for objects at different distances.
Eye
The organ of sight. The eye has a number of components. These components include but are not limited to the cornea, iris, pupil, lens, retina, macula, optic nerve, choroid and vitreous.
SIMILAR TERMS--------------------------------------
Point System
A rarely-used system of meal planning for diabetes in which foods are rated based upon calorie content, regardless of blood glucose effect or nutritional content. One "calorie point" equals 75 calories. The system may have a role to help with weight loss, but is not typically presently recommended for type 1 diabetes. |Compare to carbohydrate counting and Exchange Lists.
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Perceptually lossless compression
An image processing technique with loses some information about contents of the image, but the distortions produced by the loss aren't visible to the human image processing system.
Peri-Stimulus time histogram
Plot of the average number of action potentials at each moment in time following a brief test flash.
Photopic
Bright light conditions where only the cones are functional.
Photoreceptor mosaic
The spacial arrangement of photoreceptors in the retina.
Pigment epithelium
Cells lining the back of the eye containing melanin which resynthesize photopigment for photoreceptors.
Pointspread
Poles (of optic flow field)
The two points in the optic flow field surrounding an observer moving through the environment at which there is no flow of optic texture. One is the point toward which the observer is moving and the other is the point away from which the observer is moving.
Pool hypothesis
Hypothesis for the mechanism for stereopsis. Suggests the visual system contains three pools, one for crossed disparities, one for uncrossed disparities and one for non-zero disparities. A particular depth is signaled by the relative activity of crossed and uncrossed pools rather than by a sharply tuned neuron coding a particular depth.
Pop-Out
Target items in a visual search that have features which allow them to be detected quickly regarless of the nummber of distractors presents are said to "pop-out".
Post stimulus time histogram
A method for examining cell response to a particular stimulus. The time after stimulus onset is divided into a number of bins. The stimulus is then presented repeatedly and the count in each bin increased each time the cell fires during that time bin.
Prelunate cortex
Area V4 in rhesus monkey brain.
RELATED TERMS--------------------------------------
Optical
Having to do with vision.
Natural
Not human-induced or manmade.
Lens
The lens of the eye is like an adjustable lens of a camera and focuses light rays on to the retina for sharp images. A condition called presbyopia occurs when the lens is no longer able to adjust for objects at different distances.
Eye
The organ of sight. The eye has a number of components. These components include but are not limited to the cornea, iris, pupil, lens, retina, macula, optic nerve, choroid and vitreous.
SIMILAR TERMS--------------------------------------
Point System
A rarely-used system of meal planning for diabetes in which foods are rated based upon calorie content, regardless of blood glucose effect or nutritional content. One "calorie point" equals 75 calories. The system may have a role to help with weight loss, but is not typically presently recommended for type 1 diabetes. |Compare to carbohydrate counting and Exchange Lists.
PREVIOUS AND NEXT TERMS--------------------------------------
Perceptually lossless compression
An image processing technique with loses some information about contents of the image, but the distortions produced by the loss aren't visible to the human image processing system.
Peri-Stimulus time histogram
Plot of the average number of action potentials at each moment in time following a brief test flash.
Photopic
Bright light conditions where only the cones are functional.
Photoreceptor mosaic
The spacial arrangement of photoreceptors in the retina.
Pigment epithelium
Cells lining the back of the eye containing melanin which resynthesize photopigment for photoreceptors.
Pointspread
Poles (of optic flow field)
The two points in the optic flow field surrounding an observer moving through the environment at which there is no flow of optic texture. One is the point toward which the observer is moving and the other is the point away from which the observer is moving.
Pool hypothesis
Hypothesis for the mechanism for stereopsis. Suggests the visual system contains three pools, one for crossed disparities, one for uncrossed disparities and one for non-zero disparities. A particular depth is signaled by the relative activity of crossed and uncrossed pools rather than by a sharply tuned neuron coding a particular depth.
Pop-Out
Target items in a visual search that have features which allow them to be detected quickly regarless of the nummber of distractors presents are said to "pop-out".
Post stimulus time histogram
A method for examining cell response to a particular stimulus. The time after stimulus onset is divided into a number of bins. The stimulus is then presented repeatedly and the count in each bin increased each time the cell fires during that time bin.
Prelunate cortex
Area V4 in rhesus monkey brain.
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This dictionary contains 19186 terms.
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