JP2643958B2 - Endoscope image enhancement circuit - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color enhancement circuit for an endoscope that performs color enhancement only in a specific area such as an endoscope image portion.

[Related Art] In recent years, a television camera using a solid-state imaging device such as a CCD as an imaging unit has become widespread, and has been used for an endoscope and the like.

In the case where the above-mentioned imaging means is used, there is an advantage that it is easy to make the feature of interest noticeable by performing signal processing because it is an electric signal.

By the way, for example, an endoscope image may be reddish and tend to concentrate on a narrow range on a hue plane, and it is convenient if the endoscope image can be easily identified. For this reason, there is a color enhancement circuit that emphasizes the color tone.

As the above-mentioned color enhancement circuit, for example, the present applicant has proposed a color enhancement circuit applied to an endoscope in Japanese Patent Application No. 62-69912.

FIG. 8 shows an endoscope provided with this color enhancement circuit.

The electronic scope device 11 provided with the color enhancement circuit 1 has an elongated insertion portion which can be inserted into a body cavity or the like.
An imaging lens 13 is disposed on the tip side of the
A solid-state image sensor 14 such as a CCD is arranged on a focal plane of the lens and an image pickup means is formed. A light guide fiber 15 is inserted into the insertion portion 12 to transmit illumination light of an external light source device 16 so that the illumination light can be applied to the object side from the distal end surface through a light distribution lens 17. It is.

The light source device 16 transmits the illumination light of the light source lamp 18 to the concave film 19.
This reflected light passes through the condenser lens 21 and is condensed and radiated to the incident end of the light guide cable through which the light guide fiber 15 is inserted. At the time of this condensing irradiation, the three primary color transmission filters are provided around the rotation axis,
By passing through a rotary filter 23 driven to rotate by 22, the light is sequentially irradiated with illumination light of three primary colors. Therefore, the object is sequentially illuminated with the illumination light of each of the three primary colors.

By the way, the pixel signal of the optical image which is photoelectrically converted by the solid-state imaging device 14 is amplified by a preamplifier 24 having a low noise figure, transmitted by a signal cable, and provided by a multiplexer at hand.
One frame under illumination of each color is sequentially recorded in the frame memories 26R, 26G, 26B via the A / D converter (not shown) via the A / D converter 25. These frame memories 26R, 26G, 26
The signal recorded in B is read out at the same time, and the D / A
After passing through the converter, two color difference signals RY and BY are extracted via a matrix circuit 27.

The color difference signals R-Y and B-Y are input to the color enhancement circuit 1 and the color enhancement circuit 1
A color difference signal (R
−Y) ′ and (BY) ′ are output. The color difference signals (RY) 'and (BY)' are passed through a luminance generating matrix circuit 28, whereby the luminance signal Y 'and the dye signals (RY)' and (BY) 'are converted. And the signals Y ',
(RY) 'and (BY)' are input to the NTSC encoder 29. As a result, a composite video signal is generated and displayed on the color monitor 30 in color.

[Problems to be Solved by the Invention] By the way, the above-mentioned related art example by the present applicant does not disclose means for displaying character data relating to the endoscope image together with the endoscope image.

For example, as shown in FIG. 9, the frame memories 26R, 26G,
It is conceivable that adders 31a, 31b, 31c are interposed in the subsequent stage of 26B, and the output signal of the character generation circuit 32 and the color signals R, G, B of the endoscope image from the CCD 14 are mixed. From the character generation circuit 32, not only character information such as date, patient name, gender, etc., but also when an image on a monitor is being taken by a still camera, as shown in FIG. Is displayed in a green background 33 in which the rectangular back part of the character "" becomes green. Also, when recording on a VTR, color information such as the background of the character VTR being green was also sent. As a sending method, for example, when green is added, nothing is sent from the character generation circuit to R and B, and a signal is sent only to G and added. Thus, the background of the character indicating the current state is green, so that the user can know the current state at a glance. In FIG. 9, the luminance signal Y of the matrix circuit 27 and the color difference signals (RY) ', (BY)' of the color enhancer circuit 1 are input to the NTSC encoder 29.

By the way, since the color enhancement circuit 1 applies saturation enhancement to all signal areas having color information, not only an endoscope image but also an endoscope image on a monitor screen is displayed.
There is a disadvantage that saturation enhancement is applied to a colored portion, for example, the green background 33, and the color changes like the endoscope image to make it hard to see every time the enhancement amount is changed.

The present invention has been made in view of the above points, and has as its object to provide a color enhancement circuit for an endoscope that can perform color enhancement only on an area of an endoscope image.

Means and Action for Solving the Problems The endoscopic image enhancement circuit according to the present invention has an endoscopic image signal period representing endoscopic image information and a non-endoscopic image signal period representing non-endoscopic image information. An image signal input end to which an image signal is input; enhancement designation means for designating and inputting an image enhancement of an endoscope image displayed on a monitor screen; and a timing signal corresponding to an endoscope image signal period in the image signal. Timing signal generating means to be generated, emphasizing means for emphasizing a signal change in an endoscopic image signal period in the image signal based on a designation input of the emphasis specifying means and a timing signal generated by the timing signal generating means, Is provided.

In the present invention, an image signal having an endoscopic image signal period representing endoscopic image information and a non-endoscopic image signal period representing non-endoscopic image information is input to the image signal input terminal, and the emphasis designating means is Specify and input image enhancement of the endoscope image displayed on the monitor screen. Further, a timing signal generating means generates a timing signal corresponding to an endoscope image signal period in the image signal, and an emphasizing means based on a designation input of the emphasis designating means and a timing signal generated by the timing signal generating means. The change of the signal in the endoscope image signal period in the image signal is emphasized.

EXAMPLES Hereinafter, the present invention will be described specifically with reference to the drawings.

1 to 6 relate to a first embodiment of the present invention. FIG. 1 is a block diagram showing an electronic endoscope apparatus provided with the first embodiment, and FIG. 2 is a color enhancement apparatus of the first embodiment. FIG. 3 is a timing chart for explaining the operation of the first embodiment, FIG. 4 is a diagram for explaining the operation of the window comparator, and FIG. 5 shows that color enhancement is performed only in the endoscope image area. FIG. 6 is an explanatory view showing color emphasis by color vector coordinates.

As shown in FIG. 1, an endoscope device 41 having the first embodiment is provided.
Is an electronic endoscope (also referred to as an electronic scope) 42, a light source unit 43 for supplying illumination light to the electronic scope 42, a signal processing unit 44 for performing signal processing on the electronic scope 42, and a signal processing unit 44. And a monitor 45 for displaying the output video signal in color. The signal processing unit 44 houses the color enhancement circuit 46 of the first embodiment.

The electronic scope 42 has an elongated insertion portion 47 so that it can be inserted into a body cavity, and a distal end portion of the insertion portion 47 has an objective lens 48 and a solid-state imaging device 49 such as a CCD on a focal plane of the objective lens 48. It is arranged to form an imaging means. A light guide fiber 51 is inserted into the insertion portion 47, transmits illumination light supplied from an external light source 43, and irradiates the object side from the distal end surface thereof through a light distribution lens 52. I can do it.

The light source 43 reflects the illumination light of the light source lamp 53 by the concave mirror 54, and the reflected light is condensed and radiated through the condenser lens 55 to the incident end of the light guide cable through which the light guide fiber 51 is inserted. When this light is focused,
By providing three primary color transmission filters around the rotation axis and passing through a rotation filter 57 that is rotated by a motor 56,
Illuminated with primary color illumination light. Therefore, the object is sequentially illuminated with the illumination light of each of the three primary colors.

By the way, the pixel signal of the optical image photoelectrically converted by the solid-state imaging device 49 is amplified by a preamplifier 58 having a low noise figure, transmitted by a signal cable 59, and A / D in the signal processing unit 44.
The signal is input to the converter 61 and converted into a digital signal. These digital signals are sequentially recorded in the frame memories 63R, 63G, 63B via the multiplexer 62 for one frame under illumination of each color. These frame memories 63R,
The signals recorded by 63G and 63B are simultaneously read out and converted into analog color signals by D / A converters 64i (i = a, b, c), respectively. The output signal of each D / A converter 64i is added to an adder 65
i, respectively, and added to the character signal output from the character generation circuit 66 to form a matrix circuit 67
, Two color difference signals RY, BY and a luminance signal Y are generated.

The color difference signals RY and BY are input to the color enhancement circuit 46 of the first embodiment. The color enhancement circuit 46 outputs color difference signals (RY) 'and (BY)' in which the saturation for the desired hue is emphasized.

The luminance signal Y from the matrix circuit 67 and the color difference signals (RY) ', (B-
Y) 'is input to the NTSC encoder 68. Thus, a composite video signal is generated, and is displayed in color on the color monitor 45.

Incidentally, the color enhance circuit 46 has the configuration shown in FIG.

The output signal of the adder 65i is a quadrature modulation / hue difference detection circuit 70.
Are input to a quadrature modulation circuit 71 and a multiplication circuit 72 for saturation enhancement.

The color difference signals RY, B-
Y is multiplied by the signals of sin θ and cos θ by the multipliers 73 and 74, respectively, added by the adder 75, and output as a quadrature modulation signal A (φ _A ). In this case, sinθ, cosθ
It is convenient to use the 3.58 MHz signal used in the NTSC encoder 68 because the existing circuit can be diverted. The output signal A (φ _A ) of the adder 75 is the sin signal shown in FIG.
As shown in FIG. Becomes Note that this phase angle is φ _A = tan ⁻¹ (RY) /
(BY).

On the other hand, an emphasis color designating circuit 76 for designating (a center color of) a color to be intensified is constituted by a phase shifter 77, and the hue signal M to be enhanced is designated.
(Φ _M ) is output. This output waveform is shown in FIG.

The output signal A of the quadrature modulation circuit 71 and the output signal M of the phase shifter 77 are calculated by a comparator 7 forming a hue difference detection circuit 78.
The signals are respectively input to 9, 80 and are compared with the 0 potential. The output signal A is applied to the non-inverting input terminal of the comparator 79, and outputs a signal having a waveform as shown in FIG. 3 (d). The output signal M of the phase shifter 77 is applied to the inverting input terminal of the comparator 80. Applied to output the waveform shown in FIG. 3 (e). The reason for using the inverted output in the comparator 80 is to obtain a hue difference from -180 ° to + 180 °.

The output of the comparator 80 is applied to the set terminal of the flip-flop 81, and when the signal rises, the output of the flip-flop 81 goes high. The output of the comparator 79 is applied to the reset terminal of the flip-flop 81,
When the signal rises, the output of the flip-flop 81 is set to low level. The output of the flip-flop 81 is shown in FIG.
Shown by way phi _A to - (φ _M -180 °) has a rectangular wave having a corresponding pulse width, at slice circuit 82, then is sliced to a constant amplitude pass filter 83
, The pulse width becomes φ _A- (φ _M -180 °)
Is converted to a voltage signal proportional to. Here the slice circuit
The reason for slicing to a constant amplitude at 82 is that the slice circuit 82
Can be constituted by a differential amplifier, and a temperature stable circuit can be obtained. The output of the low pass filter 83 is the way, φ _A - (φ _M -180 °) = φ _A -
DC voltage component corresponding to the 180 ° component by the subtracter 84 from a phi _M +180 DEG is subtracted, the voltage corresponding to φ _A -φ _M. The output of the subtractor 84 is input to the window comparator 85, and the processing shown in FIG. 4 is performed.

That is, the output φ of the low-pass filter 41 through the subtractor 42
To _A -.phi _M, it is set to 0 level near to indicate levels compared to 4 (a), in the range phi _A -.phi _M
, The window comparator 85 outputs a pulse as shown in FIG. The output of the window comparator 85 is input to a pulse variable resistor 86, divided by the pulse variable resistor 86, further added with the potential V of the voltage source 87, and added by the adder 88 to the voltage Vr of the variable voltage source 89. The hue difference detection circuit 78 outputs a signal of an enlarged hue difference by adjusting the DC level of the signal by adding. This signal is input to the multipliers 92 and 93 forming the saturation emphasis multiplication circuit 72 via the analog switch 91.

The signals input to the multipliers 92 and 93 are respectively multiplied by the input color difference signals R-Y and B-Y. At this time, the enhancement signals (RY) ', (B-
Y) 'is output.

The analog switch 91 includes a timing signal generation circuit
The switching of the contacts a and b is controlled by 94.

The timing signal generation circuit 94 selects the contact a when the endoscope image signal is input, and selects the contact b other than the endoscope image signal. A constant voltage Vm (for example, 1 [V]) is applied to the contact b. In this case, since the multipliers 92 and 93 have a multiplication factor of 1, the color difference signals RY, BY is output to the next stage.

By the way, the output of the adder 88 is as shown in FIG. 4 (c). Therefore, when there is no hue difference from the color to be emphasized by the multipliers 92 and 93, the output is multiplied by a voltage of 1 V or more, and the color to be emphasized and the hue difference are In some cases, the saturation is reduced by multiplying the voltage by 1V or less. Here, the signal multiplied by the multipliers 92 and 93 is a pulse, but the waveform may be cut into a normal distribution shape by cutting a high-frequency component with a low-pass filter or the like, or may have another shape. This waveform is often based on experience.

Note that the timing generation circuit 94 generates a switching signal that becomes “H” level only during a period during which an endoscope image is displayed, based on an output signal or a gate signal of an endoscope screen shape generation circuit (not shown), for example. The switching of the switch 91 is controlled.

FIG. 5 shows the operation of switching the analog switch 91 by the timing signal generating circuit 94.

An endoscope image is displayed on the monitor screen as shown in FIG.
In the case where 96 and character data 97 are displayed, the color enhancement circuit 46 outputs a character data signal 97a and an endoscope image signal 96a to the scanning portion indicated by reference numeral 98 as shown in FIG. Is entered. In this case, the timing signal generating circuit 94 becomes "H" as shown in FIG. 5 (c) corresponding to the image display area of the endoscope image 96, and the "H" signal causes the analog signal only during this period. The switch 91 selects the contact a side, and therefore, the saturation enhancement is performed only during this period. Since the contact b side is selected except for “H”, the saturation enhancement is not performed, and the input to the color enhancement circuit 46 is performed. The output signal is output to the next stage as it is. Therefore, the endoscope image 96
Only the region performs color enhancement for saturation enhancement, and the character data 97 and the green background 99 can be displayed in the same color. Therefore, even if the enhancement amount is changed, the color does not change, so that it is not difficult to see.

The endoscope image 96 is emphasized as shown in FIG.

In the color vector coordinates using the color difference signals RY and BY as coordinate axes, the color vector of the color to be emphasized is set, and one of the color vectors forming the image is provisionally set. By passing through the color enhancement circuit 46, the saturation of the color signal in the vicinity of the color vector is enhanced.
Where the color vector of the hue difference deviated from this color vector has a reduced saturation and becomes like '.
By this operation, the image portion near the color vector to be emphasized can be emphasized. Therefore, as the color vector to be emphasized, for example, by setting a hue closer to the lesion than the hue of the normal part in the body cavity, if there is a lesion or the like slightly deviated from the hue of the normal part, the lesion is determined. Can be raised.

FIG. 7 shows a color enhancement circuit according to a second embodiment of the present invention.
111 is indicated.

This second embodiment is provided, for example, in place of the color enhancement circuit 46 shown in FIG. 1, and is provided between the output signal of the quadrature modulation / hue difference detection circuit 70 shown in FIG. Is provided with an analog switch 113 that can be switched by an emphasis area designating circuit 112. The emphasis area designation circuit 112 can be controlled by, for example, an operation panel of the signal processing unit 44. For example, in the endoscope image area, a signal which becomes “H” in a small circular portion or a square portion is switched to “H” in ROM by a switch operation. "The output period can be variably set. The output signal of the quadrature modulation / hue difference detection circuit 70 is output to the multiplication circuit 72 only during this" H "period, and the other outputs a voltage Vm of 1 V.

In the second embodiment, only the affected area or the area desired by the operator can be color-enhanced. In this case, the character information is not naturally color-enhanced.

Further, the contact a can be turned on manually so as to emphasize the color of the entire endoscope image.

In each of the embodiments described above, the color saturation emphasis is performed. However, the color hue emphasis may be performed, or a color enhancement circuit that enhances the color saturation and the hue may be used. Further, the present invention can be applied to a case where contour enhancement is performed.

[Effects of the Invention] As described above, according to the present invention, since means for performing color enhancement only in the endoscope image area is formed, character information displayed in a portion other than the endoscope image area is provided. And the like are not emphasized in color, and can be prevented from being unsightly.

[Brief description of the drawings]

FIGS. 1 to 6 relate to a first embodiment of the present invention.
FIG. 1 is a configuration diagram illustrating an electronic endoscope apparatus including a first embodiment,
FIG. 2 is a configuration diagram of a color enhancement circuit of the first embodiment,
FIG. 3 is a timing chart for explaining the operation of the first embodiment, FIG. 4 is a diagram for explaining the operation of the window comparator, and FIG.
FIG. 6 is an explanatory diagram showing that color enhancement is performed only in an endoscope image area, FIG. 6 is an explanatory diagram showing color enhancement in color vector coordinates, and FIG. 7 is a diagram showing a second embodiment of the present invention. FIG. 8 is a block diagram showing a prior art electronic endoscope, FIG.
FIG. 10 is a block diagram showing an electronic endoscope in which a means for superimposing character information is added to the prior example of FIG. 8, and FIG. 10 shows a state in which character information is displayed together with an endoscope image on a monitor screen in FIG. FIG. 41: Electronic endoscope device, 42: Electronic scope 43: Light source unit, 44: Signal processing unit 45: Color monitor 46: Color enhancement circuit 65a, 65b, 65c Adder 66: Character Generating circuit 67 Matrix circuit 70 Quadrature modulation / hue difference detecting circuit 72 Multiplying circuit (for saturation enhancement) 91 Analog switch 94 Timing signal generating circuit

Claims (1)

(57) [Claims] 1. An image signal input end to which an image signal having an endoscope image signal period representing endoscopic image information and a non-endoscopic image signal period representing non-endoscopic image information is inputted, and displayed on a monitor screen. Enhancement specifying means for specifying and inputting image enhancement of the endoscope image to be performed; timing signal generating means for generating a timing signal corresponding to an endoscope image signal period in the image signal; and specifying input of the emphasis specifying means. An endoscope image emphasizing circuit, comprising: an emphasizing means for emphasizing a signal change in an endoscopic image signal period in the image signal based on a timing signal generated by the timing signal generating means.