The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 31, 2000
Filed:
Oct. 02, 1997
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An image sensing element for providing a series of voltage signals corresponding to a two-dimensional image, a two-dimensional analog DCT (discrete cosine transform) circuit for performing a two-dimensional DCT on the voltage signal series from the image sensing element in pixel blocks, and a quantization circuit for quantizing a result of the DCT are provided. The two-dimensional analog DCT circuit is formed of a row of analog sum-of-products arithmetic units for one-dimensional DCT and an analog memory array for matrix transposition. The quantization circuit converts a voltage representing a result of the DCT carried out by the two-dimensional analog DCT circuit into a digital value according to a given quantization coefficient Q=2.sup.N .multidot.S(1.ltoreq.S<2) wherein a voltage S.multidot.Vref that is S times greater than a fixed voltage Vref serves as a reference voltage, and performs a process of right-shifting the digital value N bits in order to provide a quantized digital value.