JPS6089169A - Picture information reduction processing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an image information reduction processing method, and particularly to a method for obtaining density information of one reduced pixel from density information of a plurality of original pixels.

[Background of the invention]

Conventionally, when converting information signals of a plurality of original pixels having density information into information signals of one reduced pixel having density information, the density information of the reduced pixel information signal is converted into information of all original pixels to be reduced. There are two methods: one is to obtain the density information of the signal by averaging the other, and the other is to extract the density information of one original pixel from the original pixel information signal to be reduced.

However, the former method has the disadvantage that when the reduction ratio of the pixel information signal becomes large, there are few changes in the shading of the reduced image due to the effect of averaging, and the image becomes flat and the contours are not clearly visible. Furthermore, the latter method has the disadvantage that the change in shading of the reduced image is discontinuous.

[Purpose of the invention]

An object of the present invention is to provide an image information reduction processing method that can faithfully reduce an original image.

[Summary of the invention]

To achieve this object, the present invention provides an image information reduction processing method for converting information signals of a plurality of original pixels having density information into an information signal of one reduced pixel having density information. The present invention is characterized in that the density information of the original pixel information signal is extracted for a plurality of pixels in order from the one with the maximum density and is averaged, and the averaged value is taken as the density information of the information signal of one reduced pixel.

[Embodiments of the invention]

FIG. 1 shows an overall block diagram of an image reduction device that implements the method of the present invention. The reading device (if, i) is equipped with a rotating drum 2 and a photoelectric conversion means 3, and the photoelectric conversion means 3 converts the density of the original image of the original image attached to the rotating drum 2 and rotates into an electrical signal, and has density information. The image information reduction processing means 5 converts the plurality of original pixel information signals S1 inputted from the photoelectric conversion means 3 into one reduced pixel information signal S2. This reduced pixel information signal S2 includes, as density information, a value obtained by extracting the density information of the original pixel information signal S1 to be reduced for a plurality of pixels in order from the highest density one and averaging it. is input to record the reduced image on the recording paper 7.

The signal of the microcomputer when the image of the document 4 is reduced to 1/4 size and recorded on the recording paper 7 as shown in FIG. 2 by software processing using a microcomputer as the image information reduction processing means 5. The processing flow will be explained with reference to FIG. In FIG. 2, reference numeral 8 indicates an original pixel, reference numeral 9 indicates a reduced pixel, and one reduced pixel 9 is obtained by performing reduction conversion processing on the signals of 16 original pixels B.

When a command to start signal processing is input in step 10, initialization processing is executed in step 11, and the process moves to step 12.

In step 12, 16 to be reduced, which is indicated by diagonal lines in FIG.
Read the density data of the original pixels 8 and proceed to the next step 1.
Move on to 3. In step 13, among the density data of the 16 original pixels 8, the density data of eight original pixels 8 are extracted in descending order of density, starting from the highest density one, and the process moves to the next step 14.

Step 14 calculates the average value of the extracted eight original pixel density data, and step 15 outputs this average value as density data of one reduced pixel 9.

In step 16, it is determined whether or not the above-mentioned reduction process has been completed for all original pixels 8. If it has not been completed, the process returns to step 12 and the above-mentioned reduction process is repeated; if it has not been completed, the process moves to step 17. to end the reduction process.

FIGS. 4 to 6 show examples in which the image information reduction processing means 5 is constituted by an electronic circuit, and image information is reduced by hardware processing. FIG. 4 is an overall block diagram of the image information reduction processing means, FIG. 5 is a block diagram of the image information reduction circuit,
FIG. 6 is a density data shift timing chart.

This hardware processing circuit also has a signal processing function similar to the signal processing flow by the microcomputer described above.

The four line memories 21 to 24 are controlled by the line memory control circuit 25 and store the original pixel information signals 81 of the four scanning lines to be reduced line by line, and each store the original pixel information signals for four pixels. Output one by one. The image information reduction circuit 2G reduces the information signals of 16 original pixels and outputs the information signal B2/ of one reduced pixel. The buffer memory 27 is controlled by the buffer memory control circuit 28 to store the reduced pixel information signal 82' and output it to the printer as a series of reduced pixel information signals S2.

The image information reduction circuit 26 includes the above-mentioned line memories 21 to
It is provided with 16 shift registers 30 to 32 for each pixel to store the original pixel information signal Sl' of 166 pixels input from 24. Each of these shift registers 30 to 32 stores The generated original pixel information signal <m degree data) is transmitted to each shift register 3 by shift clocks 44 to 46 from the shift clock generation circuit 29.
1 connected in cascade from the most significant bit every 0 to 32
6 serial manual/parallel output shift registers 33
Transferred to ~35. The output circuit of each shift register 30-32 has one 7-lip flop 38-40, respectively.
is connected, and it is detected that the density data of each original pixel to be transferred becomes the No-Y level for the first time. The density data stored in the shift registers 30 to 32 that first output the high level becomes the maximum density of the 16 original pixels to be reduced, and the shift register 30 that outputs the high level second
The density data stored in .about.32 is the second density. Therefore, the seven lip-flops 38-40 are triggered in the order starting from those connected to the shift registers 30-32 in which high-density data is stored. The outputs of the triggered flip-flops 30-32 are provided via a multiplexer 41 to a counter 42, which counts the triggered flip-flops 38-40. Note that if there is a plurality of density data of the same density transferred from each shift register 30 to 32 to shift registers 33 to 35, a plurality of flip-flops 38 to 40 will be triggered at the same time, and the counter 42 will not be able to count correctly. , from the shift clock generation circuit 29 to each shift register 30 to 32.3.
Shift clocks 44 to 46 applied to clocks 3 to 35 are shifted in phase as shown in FIG. counter 42 is 8
After counting the number of triggered flip-flops 38 to 40, the output of counter 42 is provided to shift register selection circuit 43. The shift register selection circuit 43 is connected to input the outputs of the flip-flops 38 to 40, and when the output of the counter 42 is generated, the shift register selection circuit 43 selects the shift register to which the flip-flops 38 to 40 that have been triggered have been connected. Shift registers other than registers 33~
35 to a clear state. Only the density data of the eight upper density original pixels are transferred and stored in the shift registers 33-35. The adder 36 inputs the outputs of the shift registers 33 to 350, and the value given from the adder 36 to the divider 37 is the eighth value from the maximum density of the 16 original pixels to be reduced. This is the sum of the concentration data.

The divider 37 reduces the input value to 1/8, averages it, and outputs it as density data 82' of one reduced pixel.

Even with such hardware processing, a reduced image similar to the above-mentioned software processing can be obtained.

In the embodiment described above, 16 original pixels are reduced to one reduced pixel, and the density data of the reduced pixel is also calculated from the density data of the eight original pixels with higher density. The number can be set arbitrarily.

Further, the original pixel information signal may be one extracted from a TV signal or a VTR signal.

〔Effect of the invention〕

As described above, according to the present invention, the density information of the original pixel information to be reduced is extracted for a plurality of pixels in order from the highest density, and the information is averaged, and this averaged information is used as the information signal of one reduced pixel. Since the density information is used as density information, it has the effect of faithfully reducing the original image.

[Brief explanation of drawings]

Fig. 1 is an overall block diagram of an image reduction device that implements the method of the present invention, Fig. 2 is a schematic diagram of pixel reduction, Fig. 3 is a flowchart of reduction processing by a microcomputer, and Figs.・-A processing means and timing chart for software processing; FIG. 4 is an overall block diagram of the image information reduction processing means, FIG. 5 is a block diagram of the image information reduction circuit, and FIG. 6 is a shift clock timing chart. It is. 5... Image information reduction processing means, 8... Original pixel, 9...
...Reduced pixels. Agent Patent Attorney Akio Takahashi f Illustration 4

Claims (1)

[Claims] 1. In an image information reduction processing method that converts information signals of a plurality of original pixels having density information into one reduced pixel υ information signal having density information, the information signals of a plurality of original pixels to be reduced. An image information reduction processing method characterized in that density information of a plurality of pixels is extracted in order from the one with the maximum density and averaged to obtain density information of an information signal of one reduced pixel.