发明名称 |
VISUAL ACUITY TESTER |
摘要 |
A visual acuity tester based on a personal computer is provided that is capable of displaying visual acuity test characters at varying sizes on a monitor. The visual acuity tester antialiases the test characters to overcome the effects of staircase distortion. Preferably, the visual acuity tester performs unweighted area sampling antialiasing. The visual acuity tester also centers the test characters relative to the pixel array of the monitor to improve the appearance of the test characters. The test characters can be centered relative to either the center of a pixel or the corner of a pixel (a pixel coordinate). Test characters can also be centered relative to a pixel center in one dimension and a pixel coordinate in the other dimension.
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申请公布号 |
CA2270246(A1) |
申请公布日期 |
1998.05.07 |
申请号 |
CA19972270246 |
申请日期 |
1997.10.23 |
申请人 |
MENTOR CORPORATION |
发明人 |
WALTUCK, MOREY HERBERT;MCKNIGHT, ROBERT NELSON;TOLKSDORF, KURT PAUL;STARR, JOHN DONAL |
分类号 |
A61B3/028;A61B3/032;G09G5/28;(IPC1-7):A61B3/032;G06T11/20 |
主分类号 |
A61B3/028 |
代理机构 |
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代理人 |
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地址 |
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