JPH06332667A - Encoding device - Google Patents

Abstract

PURPOSE:To always execute optimal encoding for input data. CONSTITUTION:This device is provided with a first encoder 1 for encoding input data, a first memory 2 for storing encoded data in a prescribed encoding interval from a first encoder 1, a first counter 3 for counting the encoded data quantity encoded by a first encoder 1, a second encoder 4 for executing encoding which is different from first encoding for the input data, a second memory 5 for storing the encoded data in the prescribed encoding interval from a second encoder 4, a second counter 6 for counting the encoded data quantity encoded by a second encoder 4, and a selector 8 for comparing count values of a first and a second counters at every prescribed encoding interval and fetching the encoded data responding to a smaller count value from one of two memories 2, 5.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a coding device.

[0002]

2. Description of the Related Art Encoding devices are used to compress image data such as electronic files. In such an encoding device, as shown in FIG.
It was encoded by 0.

[0003]

As described above, in the conventional example, the input data is simply encoded by one system. Therefore, the input data is not necessarily optimized for encoding, and the code length sometimes becomes long. For example, when MR coding is selected, since the k parameter is conventionally set, one-dimensional coding is originally performed even when the code length of the previous scan line is shorter when the two-dimensional coding is performed. On the contrary, two-dimensional encoding is performed even on a line that should be subjected to one-dimensional encoding and has no correlation with the previous scanning line, resulting in a long code length.

In the example of MR encoding, there is a two-dimensional extension mode in the line where the correlation is lost, and there is also a mode in which the subsequent code is treated as a one-dimensional code by the addition of the special code. However, some LSIs or software for decoding processing are not compatible, and there are cases where decoding is not possible.

An object of the present invention is to provide an encoding device that solves the above problems.

[0006]

In order to achieve the above object, the present invention provides a first encoder for encoding input data, and encoded data within a predetermined encoding section from the first encoder. For storing input data, a first counter for counting the amount of encoded data encoded by the first encoder, and an encoding different from the first encoding for input data. A second encoder for performing, a second memory for storing encoded data in a predetermined encoding section from the second encoder, and an encoding encoded by the second encoder The second counter that counts the amount of data is compared with the count values of the first and second counters for each predetermined encoding interval, and the encoded data that responds to the smaller count value is compared with the second counter.
And a means for taking out from any one of the two memories.

[0007]

According to the present invention, for example, each scan line as input data is encoded by two different encoding systems, and each of them is provided with a memory for each scan line and temporarily stored, and at the same time, each scan line is encoded. The coded data amount is coefficientd by each counter, the two coefficient values are compared at the end of each scanning line, the coding with the smaller system numerical value is selected, and the coded data is read from the memory to optimize the coding. I do. Furthermore, M
In the R coding, the k parameter is not fixed and the k parameter is optimized by timely varying the k parameter from 1 to infinity.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a drawing best showing the features of the present invention. In FIG. 1, 1 is a first encoder and 2 is a memory for temporarily storing the first encoder 1 for each scanning line. ,
Reference numeral 3 is a counter for counting the encoding result of the encoder 1 for each scanning line, 4 is a second encoder for performing encoding different from that of the encoder 1, and 5 is a scanning result of the encoder 4 A memory for temporarily storing for each line, 6 a counter for counting the output result of the encoder 4 for each scanning line, 7 for comparing the count results of the counter 3 and the counter 6, and selecting an encoding result with a small number of outputs. A comparator for generating a signal and a selector 8 for selecting the output of the memory 2 or the memory 5 by the output of the comparator 7.

FIG. 2 shows the embodiment shown in FIG. 1 in more detail. Reference numeral 9 is a counter, 10 is a latch for holding the output of the counter 9 for each line, and these constitute the counter 3. . 11 is a counter, 12 is a counter 1
Latches which hold the output of 1 and which form a counter 6. Reference numeral 13 is a selector for selecting the latches 10 and 12, and 14 is a down counter for reading 1 line data.

The input data is given to the encoder 1 and the encoder 4, and the respective data are encoded. The output of the encoder 1 is given to the memory 2 and the counter 9, and the output of the encoder 4 is the memory 5 and the counter 11.
Given to. If FIFO (first in first out) memories are used for the memories 2 and 5, the circuit is simplified.

The outputs of the encoders are held in the memories 2 and 5 for one line, and at the same time, the encoded data amount for one line is counted by the counter 9 and the counter 11. At the end of one line, the count amounts are held in the latches 10 and 12, respectively, and are compared by the comparator 7, and the encoding memory having a small data amount is selected by the selector 8 and the data amount is also transmitted through the selector 13. Are given to the counter 14.

At the same time when the next line input is started, the data amount is latched in the counter 14. At the same time, the values of the counter 9 and the counter 11 are cleared, and the memories 2, 5
Among them, the unused memory is cleared and the next line data repeats the above operation.

The memory to be used is read by the value of the counter 14 and passed to the subsequent processing.

If one-dimensional encoding of MR encoding is selected for the encoder 1 and two-dimensional encoding of MR encoding is selected for the encoder 4, a code with a small amount of data due to one-dimensional encoding and two-dimensional encoding is always available. Therefore, the MR coding of the optimum variable k parameter system suitable for the data amount is performed.

(Other Embodiment) FIG. 3 is a view showing another embodiment of the present invention, and FIG. 4 is a timing chart thereof. In FIG. 3, 15 is a memory for temporarily storing input data, 1
Reference numeral 6 is a selector for switching between the input data and the output from the temporary storage memory 15 according to an encoding timing signal.
Other configurations are the same as those in FIG.

The input data is first supplied to the encoder 1 and the encoder 4 via the selector 16, and the output of each encoder is counted by the counters 3 and 6 for each line, and the rising edge of the encoding timing signal. Latched by and sent to the comparator 7. The comparator 7 compares and the optimum encoder is selected by the selector 8 and the output from the memory 15 is selected by the selector 16 and encoded.

Therefore, according to this structure, since the memory 15 is placed in front of the two encoders via the selector 16, the memory can be reduced by one system as compared with the first embodiment.

As described above, the two codings are performed, and the smaller one of the generated data is compared with the count number for each line of each coding and sequentially selected to optimize the coding for each line. Therefore, the coding length can be shortened. Furthermore, by selecting one-dimensional encoding and two-dimensional encoding of MR encoding as the encoding, it is possible to perform optimal encoding with a variable k parameter, and at the time of decoding, the next bit of the EOL code is one-dimensional or two-dimensional. Since only the dimensional codes are distinguished, conventional MR decoding LSI and software can be used, and more efficient encoding than MMR encoding becomes possible.

Further, since the configuration of the first embodiment is held in the memory by one-time encoding, it is possible to perform high-speed optimal encoding with almost real-time property.

[0021]

As described above, according to the present invention, optimum coding can always be performed on input data.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a detailed block diagram of the embodiment.

FIG. 3 is a block diagram of another embodiment.

FIG. 4 is a timing diagram of the embodiment.

FIG. 5 is a diagram showing a conventional example.

[Explanation of symbols]

 1,4 Encoder 2,5,15 Memory 3,6,9,11,14 Counter 8,13,16 Selector 10,12 Latch

Claims (3)

[Claims] 1. A first encoder for encoding input data, a first memory for storing encoded data in a predetermined encoding section from the first encoder, and the first encoder. A first counter that counts the amount of encoded data encoded by the encoder, a second encoder that encodes the input data different from the first encoding, and the second encoder. A second memory for storing coded data in a predetermined coding section from the encoder, a second counter for counting the amount of coded data encoded by the second encoder, and a predetermined code A code for comparing the count values of the first and second counters for each of the coded intervals and taking out the coded data corresponding to the small count value from either of the two memories. Device. 2. The first scan line of the input data according to claim 1, wherein MR one-dimensional encoding is performed by the first encoder, MR encoding is performed by the second encoder. MR one-dimensional encoding is performed by the first encoder only, and the other scan lines are encoded by setting the k parameter of the MR code in the second encoder to ∞ and performing the first encoding. EO when encoding is selected
An encoding device, wherein L data is EOL + “1”, and when the second encoding is selected, it is EOL + “0”, and variable k parameterized MR encoding is performed on the input data. 3. The encoding device according to claim 2, wherein the first encoder is shared with a one-dimensional encoding unit of the second encoder.