Objective: By means of neuropsychologic tests, to further analyse a specific chiasmal monocular visual testing behaviour, here labelled temporal blocking because of the elective ignorance of optotypes on the temporal ...Objective: By means of neuropsychologic tests, to further analyse a specific chiasmal monocular visual testing behaviour, here labelled temporal blocking because of the elective ignorance of optotypes on the temporal side of the chart. Often it is combined with impairment of reading and other cognitive impairments. Methods: Eighteen patients with lesions to the chiasm and some degree of temporal blocking aged 24 - 76 years underwent: 1) tests for visual neglect (Gothenburg test;behavioural inattention tests: star cancellation;line bisection);2) visuo-perceptual tests;and 3) a test involving reading a crowded ten-letter and cipher bar. Results: The temporal blocking in two patients recovered after emergency neurosurgery and their results were normal when subsequently tested. Of the 16 patients with deficiencies, 14 had a poorer left eye (p Conclusions: The best neuropsychologic tests appeared to be those for visual neglect and the crowded bar test. In most cases, the right cerebral hemisphere’s lack of some crossed information from the left eye, usually needed for normative saccades and adjustment to visual space, may be a factor underlying the specific visual behaviour.展开更多
Discusses block truncation coding (BTC) a simple and fast image compression technique suitable for real time image transmission with high channel error resisting capability and good reconstructed image quality, and it...Discusses block truncation coding (BTC) a simple and fast image compression technique suitable for real time image transmission with high channel error resisting capability and good reconstructed image quality, and its main drawback of high bit rate of 2 bits/pixel for a 256 gray image for the purpose of reducing the bit rate, and introduces a simple look up table method for coding the higher mean and the lower mean of a block, and a set of 24 visual patterns used to encode 4×4 bit plane of the high detail block and proposes a new algorithm, when needs only 19 bits to encode 4×4 high detail block and 12 bits to encode the 4×4 low detail block.展开更多
文摘Objective: By means of neuropsychologic tests, to further analyse a specific chiasmal monocular visual testing behaviour, here labelled temporal blocking because of the elective ignorance of optotypes on the temporal side of the chart. Often it is combined with impairment of reading and other cognitive impairments. Methods: Eighteen patients with lesions to the chiasm and some degree of temporal blocking aged 24 - 76 years underwent: 1) tests for visual neglect (Gothenburg test;behavioural inattention tests: star cancellation;line bisection);2) visuo-perceptual tests;and 3) a test involving reading a crowded ten-letter and cipher bar. Results: The temporal blocking in two patients recovered after emergency neurosurgery and their results were normal when subsequently tested. Of the 16 patients with deficiencies, 14 had a poorer left eye (p Conclusions: The best neuropsychologic tests appeared to be those for visual neglect and the crowded bar test. In most cases, the right cerebral hemisphere’s lack of some crossed information from the left eye, usually needed for normative saccades and adjustment to visual space, may be a factor underlying the specific visual behaviour.
文摘Discusses block truncation coding (BTC) a simple and fast image compression technique suitable for real time image transmission with high channel error resisting capability and good reconstructed image quality, and its main drawback of high bit rate of 2 bits/pixel for a 256 gray image for the purpose of reducing the bit rate, and introduces a simple look up table method for coding the higher mean and the lower mean of a block, and a set of 24 visual patterns used to encode 4×4 bit plane of the high detail block and proposes a new algorithm, when needs only 19 bits to encode 4×4 high detail block and 12 bits to encode the 4×4 low detail block.
