Method and apparatus for increasing the visibility of low-contrast images
First Claim
1. A method for increasing the visibility of a first area of an image which differs in brightness from a second area of said image, said method comprising:
- periodically varying the brightness level of said first area of said image while maintaining the brightness level of said second area of said image constant.
1 Assignment
0 Petitions
Accused Products
Abstract
Method and apparatus for increasing the visibility of low contrast images. In accordance with the invention, the visibility of a selected area of an image is increased relative to another area of said image which differs only slightly in brightness from said selected area by causing said selected area to periodically vary in brightness while maintaining the brightness of said other area constant.
The apparatus for carrying out the invention comprises an optical circuit including an electro-optic photosensitive storage device having a photosensitive characteristic in which the conductance of the device varies as a function of the intensity of the radiation incident upon it, and an electro-optic birefringent characteristic in which the birefringence varies as a function of an electric field applied across it. An image of an object is read into the device which is then read-out onto a screen by placing the device between two polarizers in a readout light beam. Additionally included between the polarizers is an optical retardation means capable of cyclically varying the retardation in the readout path between two chosen values. By cyclically varying the retardation between said chosen values, one area of the output image can be maintained at a constant brightness while all other areas of different original brightness will be caused to cyclically "flicker" above and below the constant brightness level. This "flicker" will make those areas more readily discernible.
-
Citations
12 Claims
-
1. A method for increasing the visibility of a first area of an image which differs in brightness from a second area of said image, said method comprising:
- periodically varying the brightness level of said first area of said image while maintaining the brightness level of said second area of said image constant.
- View Dependent Claims (2, 3)
-
4. Apparatus for increasing the visibility of a first area of an object which differs in brightness from a second area of said object, said apparatus comprising:
-
a. an electro-optic photosensitive storage device having a photosensitive characteristic in which the conductance of the device varies as a function of the intensity of the radiation incident upon it, and an electro-optic birefringent characteristic in which the birefringence varies as a function of an electric field applied across it; b. means for reading an image of said object into said electro-optic photosensitive device; and c. means for reading said image out of said electro-optic photosensitive device and for projecting said read-out image onto an image receiving surface, said readout means including; (1) means for producing a read-out beam of radiation; (2) a pair of polarizer means; (3) means for supporting said electro-optic photosensitive device between said pair of polarizer means in said read-out radiation beam; and (4) optical retardation means between said polarizer means for cyclically varying the retardation in said read-out radiation beam whereby the brightness of the read-out image of said first area of said object will be caused to cyclically vary while the brightness of the read-out image of said second area of said object will remain constant. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12)
-
Specification