Facsimile and static presentation processing – Static presentation processing – Emulation or plural modes
Reexamination Certificate
1998-03-26
2001-04-17
Coles, Edward (Department: 2722)
Facsimile and static presentation processing
Static presentation processing
Emulation or plural modes
C358S001150, C358S001900, C358S296000, C358S426010, C382S232000
Reexamination Certificate
active
06219147
ABSTRACT:
BACKGROIIND OF THE INVENTTION
1. Field of the Invention
The present invention relates to methods and multi-functional machines having photocopying, printing, and facsimile transmission capabilities, and more particularly to the storage and processing of image data in the multi-functional machines.
2. Description of the Related Art
Photocopying machines that are capable of processing digital image data conventionally include a picture reading unit
101
, an image processing unit
102
and an image recording unit
103
, as illustrated in FIG.
5
.
The picture reading unit
101
performs a reading operation by scanning original documents and producing raw image data. The image processing unit
102
carries out processing procedures on the raw image data necessary to produce satisfactory image data, such as, for example, gamma correction and/or picture quality control for the image data. The image recording unit
103
makes hard-copy prints of the image data by arranging pixels on a suitable support material such as copy sheets.
When processed in digital form, image data may be stored in a storage medium such as, for example, semiconductor memory devices with relative ease, thereby making data processing utilizing the stored image data feasible.
The above-mentioned photocopying machine that includes storage media may be constructed such that image data is exchanged between the image storage unit
104
and the image processing unit
102
, as illustrated in FIG.
6
.
In other words, image data is read once by the picture reading unit
101
and stored once in the image storage unit
104
. Because the image data is stored, a plurality of duplicated copies may be produced from the stored data in response to a request for multi-copy print, by outputting the image data from the image storage unit
104
in place of repeatedly reading original documents for the number of times required. By this construction, the photocopying machine can be operated more quietly without reading the original repeatedly, and also photocopies can be produced more quickly by operating the image recording unit
103
faster than the recording unit
101
. In practice, it is known that the image recording unit
103
is designed to be operated faster than the picture reading unit with relative ease. Such photocopying machines are commercially available at the present time.
Furthermore, the image storage unit
104
may also be operated such that image data may be reproduced in a rotated (or reverse) manner by outputting the image data in an order different from that of inputting the image data.
Because of these data processing procedures, image data which are processed in digital photocopying machines are generally required to have high picture quality. Accordingly, image data are categorized in multiple gradations, wherein image data are expressed, for example, by combinations of 8 bits or the gray level of 256.
However, when storing these multiple valued image data without first compressing the data by data compression, a considerable volume of memory is required. Therefore, the image data are conventionally stored succeeding a coding operation and thereby reducing the data volume.
As one of the methods of coding the image data and reducing the data volume, fixed length block truncation encoding may be adopted as now described. Referring to
FIG. 7
, an original image is firstly divided into a plurality of blocks. For each of pixels in one of the blocks, a gray scale value Lij is obtained. The thus obtained gray scale values L
ij
's are then subjected to coding procedures, wherein an average gray scale value La (1 byte), a gray scale deviation index L
d
(1 byte) and a quantized gray scale value for each pixel L
ij
(2 bits×16 pixels) are coded according a coding scheme shown in FIG.
8
.
As shown in
FIG. 9
, image data of one block which consist of 4×4 pixels and amounts to 16 bytes, can be reduced to 6 bytes by this coding procedures, which is three eighths of the original data volume.
The decoding procedures are carried out as illustrated in
FIG. 10
, wherein a gray scale value for each pixel L*
ij
is calculated from the average gray scale value La, gray scale deviation index L
d
, and quantized gray scale value for each pixel &phgr;
ij
.
In conventional photocopying machines, there have been developed some multi-functional machines which have the capability of not only photocopying, but also printing and transmitting facsimile images, thereby combining the capabilities of three apparatuses in one. In such a system, the provision of an image storage unit is conceivable in order to carry out processing the digital image data, and it is preferable for such a unit to function as a temporary storage unit for printing or outputting facsimile transmission jobs.
As identified by the present inventor, image data which are conventionally outputted to printers or transmitted by facsimile apparatuses are largely in a binary format. As long as image data in the photocopying machine is in the binary format, the image recording unit having a binary compatible capability would be sufficient. However, if image data in photocopying machines are multiple valued, it becomes necessary for the image recording unit to have both a multiple valued capability for the photocopying operation and also a binary capability for the printing and facsimile transmission operations.
It may be noted at this point, that the multiple valued capability in the photocopying machines is conventionally utilized, since this capability is more advantageous from the viewpoint of high picture quality.
Also to be noted is that when a plurality of duplicated photocopies are produced from the image storage unit, a considerable volume of memory media is required. For example, when image data are stored in binary as blocks, as they are without the data compression, image data having a resolution of 400 dpi (or dot per inch) for one page of an A-4 size document amounts to approximately 2 MB (or megabytes) of memory space. Even for the case of multiple valued image data which are coded and stored according to the above-mentioned fixed length truncation encoding scheme, the image data amounts to approximately 6 MB of memory space for the A-4 size document with the resolution of 400 dpi. Therefore, these conventional image data processing procedures are not practical and not commercially advantageous for image data of many (e.g. tens of) pages of original documents to be stored.
SUMMARY OF THE INVENTION
The general purpose of this invention is to provide a digital multi-functional machine and processing procedures therefor, having most, if not all, of the advantages and features of similar employed machines and related procedures, while eliminating many of the aforementioned disadvantages of other machines and related procedures.
Accordingly, one object of this invention is to overcome the above-described limitations of conventional devices and methods. This and other objects are addressed by the present invention.
In one embodiment of the present invention, a digital multi-functional machine is provided, having at least one of a picture reading, a printing, and a facsimile transmission capability, and including a printer for making visible prints in response to a demand for image prints and prints of facsimile images, characterized in that the storage of image data may be carried out either in predetermined block units of pixels for binary image data, or in the form of data coded by a fixed length block truncation encoder by the same block units of pixels for multiple valued image data.
In another embodiment, the present invention provides a digital multi-functional machine additionally having a second data storage unit and a variable length encoding unit, characterized in that the variable length encoding unit is capable of coding, according to a variable length coding scheme, either binary image data previously stored in a predetermined block unit of pixels, or multiple valued image data previously encoded by a fixed length block truncation en
Coles Edward
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Ricoh & Company, Ltd.
Wallerson Mark
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