Abstract:
A register unit that is capable of improving data security and minimizing the possibility of data alteration and other manipulations includes multiple registers and a bit layout circuit that is connected to the registers. The bit layout circuit stores a relationship table that defines the relationship between the register bit addresses of all the registers and designated bit addresses of addresses that are designated by an arithmetic unit for a read/write operation. Upon receipt of a write command and its data from the arithmetic unit, the bit layout circuit separates the data into bits, generates storage data by rearranging the data in compliance with the relationship table, and stores the generated data at the register bit addresses of registers indicated in the relationship table.
Abstract:
A correction-data generating unit divides, into a matrix of row blocks in a sub scanning direction and column blocks in a main scanning direction, white data on a transfer drum read by a reading unit during a predetermined time period that is shorter than a time period in which the read point of the transfer drum is returned to a position where the reading unit has started reading the first white reference member, calculates, for each column of the matrix, a correction-data candidate value corresponding to a variation ratio of a mean of data of the row blocks in the sub-scanning direction, and determines a minimum value of the calculated correction-data candidate values as the correction data. A shading-data correcting corrects the shading data by using the generated correction data. A shading correcting unit performs shading correction on image data of a document after the correction data is generated.
Abstract:
A sampling data output circuit capable of Accommodating frequency variations includes a converter portion for sampling an input data signal (402) at an oversampling frequency to output, in parallel, a plurality of fundamental signal series (p1, p2, p3, p4), a first circular shifter for receiving the plurality of fundamental signal series and outputting a plurality of first frequency shift signal series having a higher frequency than the fundamental sampling frequency, and a second circular shifter for receiving the plurality of fundamental signal series and outputting a plurality of second frequency shift signal series having a lower frequency than the fundamental sampling frequency. The first and second circular shifters create each of the signal series by selecting a signal sample out of the input fundamental signal series according to a count value of a phase shift cumulative counter and a predetermined rule related to the frequency shift.
Abstract:
An encoding/decoding method for carrying out conversion between run lengths and corresponding run length codes is provided. The run length codes has a format including a first part for storing first information and a second part for storing second information. The first information indicates the length of the code and the second information indicates the corresponding run length. The total number of bits of each of the run length codes is set as an integral multiple of a predetermined number of bits. The present encoding/decoding method is suitable for use in an image processing system, such as a facsimile machine.
Abstract:
A correction-data generating unit divides, into a matrix of row blocks in a sub scanning direction and column blocks in a main scanning direction, white data on a transfer drum read by a reading unit during a predetermined time period that is shorter than a time period in which the read point of the transfer drum is returned to a position where the reading unit has started reading the first white reference member, calculates, for each column of the matrix, a correction-data candidate value corresponding to a variation ratio of a mean of data of the row blocks in the sub-scanning direction, and determines a minimum value of the calculated correction-data candidate values as the correction data. A shading-data correcting corrects the shading data by using the generated correction data. A shading correcting unit performs shading correction on image data of a document after the correction data is generated.