JPS6034686B2 - Color information selection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color information selection method used in facsimile machines, copying machines, etc., and for recognizing a predetermined color.

When using a facsimile or copying machine, for example, there are cases where you do not want to send or copy the part with a red stamp on the document, or conversely, there are cases where you only want to send or copy the part with the red stamp on the document. . In such cases, it is necessary to recognize information given in specific colors on the document, but conventionally there has been no method for recognizing specific color information. Furthermore, if specific color information can be recognized, it is also possible to fill in a desired part of the document with a specific color so that only that part is not read. In view of these points, the present invention seeks to provide a color information selection method that can recognize a predetermined color.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a document 1 is sent by a drive device at a predetermined speed in a direction perpendicular to the paper surface for sub-scanning, and as it passes over the main scanning line, an image is formed on a solid-state scanner 3 by an optical system 2. At the same time, the optical system 4 forms an image on the solid-state scanner 6 via the filter 5.

The solid-state scanners 3 and 6 simultaneously main scan and read portions of the original 1 on the same line. For example, when it is desired to identify information given in red on the original 1, the filter 5 is a complementary color of red, that is, a cyan filter is used.
The red component of the light that passes through this filter is extremely reduced. Therefore, as shown in FIG. 2a, the solid-state scanner 3 obtains an image signal including a true white level TWL, a true black level TBL, a white level WL, a black level BKL, a blue level BL, a red level RL, etc. However, solid state scanner 6
As shown in FIG. 2b, each color level WL, BKL, and
The level WL' where L, RL, etc. are reduced by the amount shown by the diagonal lines,
They become BKL', BL', GL, and RL'. Here, since the outputs WL and BKL when reading a normal original normally exhibit almost constant values regardless of the type of original, reference voltage levels WLo and BKL close to the output voltages WL and BKL are set in advance. It is possible to leave it there. The exact same thing can be said when reading with cyan filtration applied,
Reference voltage levels WL', BKL close to WL', BKL'
'o can be set in advance. A differential circuit (not shown) takes each color signal level based on WL'o and outputs WL'o-BKL'. is the original level difference WL
When amplified until it becomes equal to o-BKLo, after being amplified by a normal amplification circuit (not shown), TWL-W
If a bias is applied by L, the white level processing result will be as follows. WL'-WL'. Since the value of is approximately 0, there is almost no change even if it is amplified, and only the bias amount, that is, an output signal of WLo is obtained, which is approximately equal to the output level WL of the scanner 3. Similarly, look at the processing results for the black level. Multiplying (WL'-BLK'o) by the amplification factor WW raw reeds E3 gives WL. ' is approximately equal to WL'・, so the result is approximately WLo-BKL, and the bias TWL
Adding one WL results in TWL-BKLo. This is approximately equal to TWL-BKL. If this is illustrated together with the processing results of other color signals, as shown in FIG. 2c, an image signal whose red level RL in particular is extremely reduced to level R is obtained. This processed signal and the image signal from the solid-state scanner 3 are compared in a differential amplifier 7 as shown in FIG. 3, and the difference is compared with a comparison voltage Ec from a comparison power supply 9 in a comparator 8. This comparison voltage Ec is calculated from the reduction amount RL-RL'' of the red level by the filter 5.
If the value is set to be larger than the maximum value of the reduction amount of each of the other color levels, only red information will be taken out from the comparator 8. On the other hand, the image signal from the solid-state scanner 3 is binarized by the binarization circuit 1, and for example, the pixels on the main scanning line of the original 1 are arranged as black BK, blue B, green G, green G, and red R. If so, a binary signal as shown in FIG. 4a is bound. If the selection signal is set to a low potential of 0'', the red color information from the comparator 8 will be transmitted to the inverter 11 by the output signal of the inverter 11.
The signal passes through the OR circuit 13 as shown in FIG. 4b and is output. Further, if the selection signal is set to a high potential 1, the output signal of the inverter 1 becomes a low potential due to this selection signal, and the red information from the comparator 8 is cut off by the AND circuit 12. The output signal of the binarization circuit 10 is gated in the AND circuit 15 by the red information from the comparator 8 which has been inverted by the inverter 14, and becomes a signal with only the red information removed. The output signal is output through the OR circuit 13 as shown in FIG. 4c. Further, in another embodiment of the present invention, a scanner having a movable system is used, and a document is scanned by this scanner.

Then, in the scanner, as shown in FIG.
The light is received by the solid-state sensor 18 through the lens 19 and the filter 20, and the other light is received by the solid-state sensor 21 through the lens 19 and the filter 20.
The light is received by The filter 20 is a complementary color to the color to be identified, and the image signals from the solid-state sensors 18 and 21 are applied to the circuit shown in FIG. 3 in the same manner as in the embodiment described above to recognize the color information. Furthermore, in another embodiment of the present invention, as shown in FIG. 6, the document 22 is sent by a drive device in a direction perpendicular to the plane of the paper to be sub-scanned, and when it passes on the main scanning line, it is solidified by an optical system 23. At the same time as the image is formed on the scanner 24, the image is formed on the solid-state scanners 29, 30 via the filters 27, 28 by the optical systems 25, 26, respectively.

The solid-state scanners 24, 29, and 30' simultaneously scan and read portions of the original 22 on the main scanning line. The filters 27 and 28 are complementary colors of colors desired to be identified on the original 22, for example red and blue. As shown in FIG. 7, the image signals from the solid-state scanners 24 and 27 are passed through a differential amplifier 31, a comparator 32, a comparison power supply 33, a binarization circuit 34, and an inverter 35, 38 similar to the circuit shown in FIG. ,
Circuit 4 consisting of AND circuits 36, 39 and OR circuit 37
0, and depending on the presence or absence of the selection signal 1, an image signal with red information removed or a rooster signal consisting only of red information is extracted. The image signals from the solid-state scanners 24 and 28 are processed through a differential amplifier 41, a comparator 42, a comparison power supply 43, a binarization circuit 44, and an inverter 4 similar to the circuit shown in FIG.
5, 48, AND circuits 46, 49, and an OR circuit 47, a circuit 501 is added, and an image signal from which blue information has been removed or an image signal consisting only of blue information is extracted depending on the presence or absence of selection signal 0. When the selection signal m has a low potential of 0, the image signal from the circuit 40 is outputted through the AND circuit 52 and the OR circuit 53 by the output signal of the inverter 51. When the selection signal m is at a high potential of 1, the output signal of the inverter 51 disappears from the selection signal plate, the image signal from the circuit 40 is cut off by the AND circuit 52, and the image signal from the circuit 50 is passed to the AND circuit 54 by the selection signal m. The signal is output through the OR circuit 53. In another embodiment of the present invention, a document is scanned by a scanner having a movable system, and in this scanner, light from the document passes through half mirrors 55, 56 and a lens 57 to a solid state sensor 58, as shown in FIG. At the same time as the light is received by the half mirror 55,
The light separated by 56 is received by solid state sensors 63 and 64 via lenses 59 and 60 and filters 61 and 62, respectively.

The filters 61 and 62 are complementary to each color to be identified, and the image signals from the solid-state sensors 58, 63 and 64 are applied to the circuit shown in FIG. 7 in the same manner as in the above embodiment to obtain color information. Recognized. As described above, according to the present invention, a first image signal is obtained by reading an image without applying a color filter, and at the same time, a second image signal is obtained by reading the image by applying a complementary color filter to the color to be identified. Since the signal is obtained and the difference between this second image signal and the above-mentioned first image signal is taken, the color to be identified or other colors can be recognized extremely easily, and furthermore, the processing of the image signal is simple. Therefore, it can be carried out using simple and inexpensive equipment.

Furthermore, in a facsimile machine or a copying machine, for example, when recognizing only a red stamp part or other parts on a document, the optical system becomes two reading systems, making it simple and inexpensive.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an image reading system in an embodiment of the present invention, FIGS. 2a, b, and c are waveform diagrams showing image signals from the image reading system, and FIG. A block diagram showing the circuit, FIGS. 4a to 4c are waveform diagrams showing output signals of each part of the electric circuit, FIG. 5 is a perspective view showing an image reading system according to another embodiment of the present invention, and FIG. A side view showing an image reading system according to still another embodiment of the present invention, FIG. 7 is a block diagram showing an electric circuit of the same embodiment, and FIG. 8 is a perspective view showing an image reading system according to another embodiment of the present invention. It is a diagram. 1...Original, 3...Solid scanner, 5...Filter, 6...
solid state scanner, 7... differential amplifier, 8... comparator, 9.
...Comparison power supply, 16...Half mirror, 18...Solid sensor, 20...Filter, 21...Solid sensor, 22...Original, 24...Solid scanner, 27,2
8...Filter, 29,30...Solid scanner, 31...
Differential amplifier, 32... Comparator, 33... Comparison power supply, 41
. . . differential amplifier, 42 . . . comparator, 43 . . . comparison power supply, 55, 56 . . . half mirror, 58 . Camellia I figure 4 figure Sei 5 figure Rare 2 figure 3 figure Hemp 6 figure Dislike 7 figure Girder 8 figure

Claims (1)

[Claims] 1 Obtain a first image signal by reading an image without applying a color filter, and at the same time obtain a second image signal by reading this image with a complementary color filter of the color to be identified, and obtain the second image signal. A color information selection method characterized in that the color to be identified or another color is recognized by determining the difference between the image signal of the first image signal and the first image signal.