JPH0338970A - Mh encoder - Google Patents

Abstract

PURPOSE:To eliminate necessity for converting the linear density of binary picture data themselves in advance by the software of a host computer for linear density conversion and to reduce the burden of the host computer by building-in linear density converting function corresponding to the binary picture data to be inputted. CONSTITUTION:A start signal 101 and an end signal 102 respectively applies the start and end timing for a shift register 2 to shift the picture data according to the clock input of a shift pulse 103 and the clocks of the shift pulse 103 are counted by a counter 3, generated and supplied to the register 2. The count number of the counter 3 is coincident with the bit number of the shift register 2 and in an MH code generator 1, a prescribed MH code 104 is generated and outputted corresponding to the input of the picture data to be outputted from the shift register 2. Thus, it is not necessary to convert the linear density of the binary picture data themselves by the software of the host computer in advance for converting the linear density and the burden is reduced for the software of the host computer.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an MH encoder.

[Conventional technology]

Generally, an MH encoder detects the line length of l-line binary image data and outputs an MF (code).

In the binary image data, an image read from a device such as a scanner is often developed bit by bit into an image buffer in a memory at a predetermined resolution.

Further, the 1MH encoder is widely applied in the field of FAX as a compression/expansion controller incorporating the 1MH encoder. In this case, the resolution of images that can be handled, that is, the linear density of image data, may differ between the transmitting-side device and the receiving-side device. For example, if the resolution of the transmitting side device is 400 dpi (dots per inch) and the resolution of the receiving side is 200 dpi, the transmitting side needs to convert the resolution of the image data to 200 dpi before transmitting it.

Conventionally, in such cases, this kind of M I- (in encoders, 194
The 7/7 binary image data is directly input manually, and therefore the linear density is uniquely determined by the read 2 Ifi image data itself.

Therefore, as mentioned above, in order to convert this linear density, which is not involved in resolution conversion, the linear density of the binary lIm image data itself must be set in advance to There is = j31J, which is converted to .

[Problem to be solved by the invention]

In the conventional MH encoder described above, as described above,
1i! In order to convert the density, the linear density of the binary image data itself must be converted into the host computer software in advance, which places a large burden on the host computer software. There are drawbacks.

[Means to solve the problem]

The M H encoder of the present invention M) (Ml which generates a code)
In the encoder, a temporary register for inputting l-line image data in the main scanning direction, a first means for manually inputting output data from the temporary register, changing the number of bits of the output data, and outputting the same; a second means for counting the clock of 07f and outputting a predetermined start signal and end signal, and inputting the output data of the first means, and using the clock through the start signal and end signal of 07f, A third means for shifting and outputting the output data by l bits, and a fourth means for generating an MH code by inputting the data output from the third means for correction. Ru.

〔Example〕

Next, the present invention will be explained with reference to the drawings. FIG. 1 is a block diagram of a first practical example of the present invention. As shown in FIG. 1, in this embodiment, temporary register 1
and shift register 2.

It is constructed by including a counter 3 and an MH code generator 4.

This embodiment is an example in which an MI-1 code corresponding to image data having a linear density of 1/2 is generated for original image data, and the number of bits is changed by simple thinning.

In FIG. 1, the te>'garry register 1 forms a register into which one line of image data is input in the main scanning direction, and the image data input to the temporary register 1 is shifted as is every l bit. Input to register 2. The image data input to shift register 2 is
The data is shifted l bits at a time according to the input timing of the shift pulse 103 and sent to the MH code generator 4.

The shift of the image data in the shift register 2 is as follows:
It starts with the start signal 101 output from the counter 3 and ends with the end signal 102. That is, the number of shifts matches the Bi-Soto number for 1947 minutes after linear density conversion.

Note that the start signal 101 and the end signal 102 are respectively used when the shift register 2 receives the shift pulse 1.
This is a signal that gives the start and end timing of shifting the image data by the clock input of 03, and is generated by counting the clock of shift pulse 103 in the counter 3, and is supplied to the register 2. counter 3
The count number matches the bit number of the shift register 2, and the M H code generator 4 generates a predetermined M H code 104 in response to the input of the image data output from the shift register 2. and output.

In this way, for two image data of 1/4 inch,
An MH code corresponding to image data having an i density of 1/2 can be generated for the original image data. In the above-mentioned MH encoding, it is impossible to perform line-by-line processing, so by repeating the above-mentioned operations, one page's worth of binary image data is encoded.

Next, a second embodiment of the present invention will be described. FIG. 2 is a block diagram of a second embodiment of the invention. As shown in FIG. 2, Honjitsu/i′! The example includes a temporary register 1, a shift register 2, a counter 3, an MH code generator 4, and a plurality of OR circuits 5.

In FIG. 2, among the binary image data input to the temporary register 1, two adjacent bits 1. The data of
The logical sum is performed in the circuit 5 and the result is input to the shift register 2. This embodiment is similar to the first example in terms of components and operation, except that the method of inputting data from the temporary register 1 to the shift register 2 is different.

In the first embodiment, since the binary image data to be MH encoded is created by simple bit thinning of the original image data, black data with a run length of l may be erased. However, in the case of this embodiment, even black data with a run length of 1 does not disappear.

〔Effect of the invention〕

As explained above in detail, the present invention corresponds to input binary image data! ! ! By having a built-in density conversion function, it is no longer necessary to convert the linear density of the binary image data itself using the host computer's software in advance for linear density conversion, which saves a large burden on the host computer's software. It has the effect of being able to reduce

[Brief explanation of drawings]

1 and 2 are block diagrams of first and second embodiments of the present invention, respectively. In the figure, 1...temporary register, 2...
...Shift register, 3...Counter,
4...M I-1 code generator, 5...
OR circuit.

Claims (1)

[Claims] An MH encoder that generates an MH code includes: a temporary register into which one line of image data is input in the main scanning direction; and an output data from the temporary register is input, and the number of bits of the output data is determined. a first means for counting a predetermined clock and outputting a predetermined start signal and an end signal; and a second means for inputting the output data of the first means and outputting the start signal. and a third means for shifting and outputting the output data one bit at a time according to the clock; and inputting the data output from the third means,
An MH encoder comprising: fourth means for generating a code;