JPS6022788B2 - Image processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image processing apparatus, and in particular to a microscope for enlarging an optical image of an object to be image processed, which is suitable for application to a blood image processing apparatus for classifying white blood cells, and a microscope for enlarging an optical image of an object to be image processed. The present invention relates to an improvement in an image processing device including one or more first photoelectric conversion means for converting an enlarged image into an electrical image signal, and a signal processing means for processing the electrical image signal output from the first photoelectric conversion means. .

In fields such as biology and medicine, microscopic objects such as chromosomes, cells, and blood cells are magnified and observed using a microscope, and the size, shape, number, color, structure, etc. of the objects are identified for research and diagnosis. It is often done to help. In such a case,
Until recently, the only way to observe and identify these objects was with the human eye, but in recent years, advances in computers and pattern recognition technology have made it possible to identify these objects without relying on the human eye. It is now done quickly and accurately by computers. In the identification of objects by computers, several issues that did not pose much of a problem when humans used to observe and identify objects with their eyes have emerged as important problems.

One of them is the non-uniformity of brightness within the microscopic field. This non-uniformity of brightness within the field of view does not pose a problem when humans observe and identify objects with their eyes. However, it has been found that this non-uniformity of brightness within the field of view poses a very serious obstacle when identifying objects using a computer. That is, in an image processing apparatus using a microscope, before starting image processing, the object to be image processed must first be positioned near the center of the field of view of the microscope.

For this purpose, a one-dimensional image sensor is installed near the center of the field of view of the microscope, and a rug stand on which the image processing object is placed is moved in a direction perpendicular to this one-dimensional image sensor, and the image processing object is searched. Do the following. When the one-dimensional image sensor detects an image processing object, the stage is controlled to position the image processing object at the center of the field of view. here
Point adjustment is performed to obtain a clear image, and then the microscopic image of the object to be imaged is converted into an electrical image signal using a two-dimensional image sensor such as a television camera. This electrical image signal is sent to image signal processing means using a computer or the like and subjected to image processing. The following describes what kind of inconveniences the non-uniformity of brightness within the field of view of a microscope causes, using a white blood cell sorting device as an example.

FIG. 1 shows an ideal situation in which the brightness within the microscope field is completely uniform. The horizontal axis in FIG. 1 represents the position within the field of view of the microscope, and the vertical axis represents the magnitude of the output signal of the one-dimensional image sensor. In the figure, the solid line A is -
It shows the change in the dimensional image sensor output signal depending on the position within the microscope field of view. The output signal of this one-dimensional image sensor includes a small drop B caused by the absorption of light by red blood cells and a large drop C caused by the absorption of light by white blood cells.
There is. From the white blood cell detection level shown by the broken line D in the figure,
When the output signal of the one-dimensional image sensor decreases, it is regarded as a white blood cell signal, and this white blood cell is positioned at the center of the microscope field of view. Next, after focus adjustment, image processing is performed to classify the white blood cells. FIG. 2 shows a state in which the brightness within the field of view of the microscope is non-uniform.

In this example, the periphery of the field of view is somewhat darker than the center. In FIG. 2, a curve indicated by a dashed line E indicates an output signal of the one-dimensional image sensor when no light is absorbed by blood cells. The solid line A in the figure is similar to that in Figure 1,
This figure shows the output signal of a one-dimensional image sensor when a glass slide smeared with blood is mounted on a microscope stage.
In FIG. 2, the signal from red blood cells is noticeably crowded at both ends of the field of view, and especially at two points, point F and point G, the red blood cell signal is lower than the white blood cell detection level D. This means that red blood cells are mistakenly detected as white blood cells at both ends of the visual field. Since erroneously detected red blood cells can be excluded at the stage of classifying white blood cells through image processing, classification accuracy is not degraded. However, since unnecessary red blood cells are also image-processed, the classification time increases significantly. Therefore, it is necessary to prevent false detection of red blood cells. Normally, the field of view of a microscope is bright in the center and gets darker toward the periphery.

In a carefully designed microscope, the reduction in brightness at the periphery of the field of view is only a few percent. This level of reduction in brightness is acceptable even in the above-mentioned leukocyte classification apparatus. However, due to a slight shift in the position of the condenser lens or a slight shift in the mounting position of the light source lamp, the brightness at the periphery of the field of view of the microscope immediately decreases, causing problems in image processing operations. The life of a microscope light source lamp is relatively short, typically on the order of several hundred hours.

If used for 5 hours a day, the lamp will have a lifespan of about 4 months, and it is necessary to replace the lamp with a new one at this interval. When replacing the lamp, the position of the lamp must be precisely adjusted in order to equalize the brightness within the field of view of the microscope. However, even if the field of view of the microscope is viewed with the naked eye through an ophthalmic lens and the lamp mounting position is adjusted so that the brightness within the field of view is uniform, it is difficult to obtain sufficient uniformity. In particular, there were large individual differences, and there were many cases in which some people could obtain almost satisfactory uniformity, while others could only obtain extremely poor uniformity. The present invention has been made to eliminate the above-mentioned conventional drawbacks, and a first object of the present invention is to provide an image processing apparatus equipped with a brightness level display means that allows easy confirmation of the brightness level within the field of view of a microscope.

The present invention also provides an image processing device that is equipped with an alarm means that can promptly detect that the brightness or the difference in brightness within the microscope field of view is out of the permissible range according to the brightness level within the field of view of the microscope. This is the second purpose.

The present invention provides a microscope that magnifies an optical image of an object to be image processed, one or more first photoelectric conversion means that converts the enlarged image of the microscope into an electrical image signal, and an output of the first photoelectric conversion means. In the image processing device, the image processing device includes a signal processing means for processing an electrical image signal, and a second photoelectric conversion means for detecting brightness at a plurality of positions within a microscope field of view and converting the detected brightness into an electrical signal;
The first object is achieved by providing a brightness level display means for displaying the brightness level within the field of view of the microscope according to the electrical signal output from the second photoelectric conversion means.

-Also, the first photoelectric conversion means is also used as the second photoelectric conversion means, and the brightness level display means displays at least a part of the electrical image signal output from the first photoelectric conversion means. This is a simplified version of the configuration.

Alternatively, the second photoelectric conversion means is a plurality of one-dimensional image sensors that detect the brightness of each layer on a plurality of lines within the field of view of the microscope and converts it into an electrical signal, and the brightness level display means The output signals of a plurality of one-dimensional image sensors are superimposed or displayed on a sliding screen so that the difference in brightness in two directions within the field of view of the microscope can be confirmed.

Further, the brightness level display means displays absolute values corresponding to brightness at each of a plurality of positions, so that the brightness distribution can be easily confirmed.

Alternatively, the brightness level display means displays an absolute value corresponding to the brightness at a predetermined position among the plurality of positions and a relative value corresponding to the brightness difference at other positions when the predetermined position is used as a reference. This makes it easy to check the brightness of the entire field of view of the microscope and the difference in brightness of each calendar.

The present invention also provides, in the same image processing device, further outputting an alarm signal when the brightness or the difference in brightness within the field of view of the microscope falls outside of a permissible range in accordance with the electrical signal output from the second photoelectric conversion means. The second object is achieved by providing an alarm means for

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

FIG. 3 shows an embodiment in which the present invention is applied to a leukocyte classification device. In FIG. 3, 1 is a blood specimen mounting mechanism, 2 is a microscope, 3 is a naked eye, 4 is a one-dimensional image sensor, 5 is a white blood cell detection and focus adjustment circuit, 6 is a microscope control circuit, 7 is a two-dimensional image sensor, 8 1 is a feature extraction circuit, 9 is a white blood cell classification and control unit, 1 is a printer, 11 is a data display unit, 1
2 is a data file section, and 13 is an optical system monitor section.
Next, the operation shown in FIG. 3 will be explained.

A blood specimen prepared by smearing blood onto a slide glass and then applying staining is set on a microscope by a blood specimen mounting mechanism 1.

This blood specimen is magnified with a microscope 2. Enlarged image is with naked eye 3
, one-dimensional image sensor 4, and two-dimensional image sensor 5, respectively. The one-dimensional image sensor 4 passes approximately through the center of the enlarged image and detects the degree of brightness across almost the entire width of the enlarged image. The output signal of the one-dimensional image sensor 4 is sent to a white blood cell detection and focus adjustment circuit 5, which generates a white blood cell detection signal and a focus signal corresponding to the sharpness of an enlarged microscope image. These signals are sent to the microscope control circuit 6. In this microscope control circuit 6, a white blood cell detection signal,
Based on the focus signal, two-dimensional position control of the microscope drum stand and position control of the objective lens are performed. These controls allow a clear magnified image of white blood cells to be obtained in the center of the field of view of the microscope. This enlarged white blood cell image is converted into an electrical image signal by the two-dimensional image sensor 7 and sent to the feature extraction circuit 8.

The image signal is processed by this feature extraction circuit 8 and becomes data representing the features of the image. The feature data of this image is also sent to the white blood cell classification and control section 9, where the white blood cells are classified. The classification results obtained by the white blood cell classification and control unit 9 are printed by the printer 10 and are also displayed on the data display unit 11.
is displayed. Also, this classification result is data file part 1
It is stored in 2. The optical system monitor section 13 displays the output signal of the one-dimensional image sensor 4 two-dimensionally, and the optical system monitor section 13 is shown in FIGS.
Further explanation will be given with reference to the figures. In Figure 4, 21
4 is an enlarged microscope image, 4 is a one-dimensional image sensor, 22 is an amplifier, 23 is a waveform conversion circuit, 24 is a voltage comparator, 25 is a focus signal generation circuit, and 6 is a microscope control circuit.

One-dimensional image sensor 4 and microscope control circuit 6 in this figure
is the same as in Figure 3. Further, 26 is a timing generation circuit, 27a to 27x are sample and hold circuits, and 28a
28x is a light emitting diode ignition circuit, and 29a to 29x are light emitting diode blocks. Next, the operation shown in FIG. 4 will be explained.

The output of the -dimensional image sensor 4 installed approximately at the center of the enlarged microscope image 21 is amplified by the amplifier 22, and then
The signal is sent to the waveform conversion circuit 23.

This waveform conversion circuit 23 converts the pulsed output signal of the one-dimensional image sensor into a smooth continuous waveform signal in which the peaks and peaks of the pulses are joined together. The output signal of this waveform conversion circuit 23 is sent to a voltage comparator 24 and used for white blood cell detection, and is also sent to a focus signal generation circuit 25 and used to generate a focus signal depending on the sharpness of the enlarged microscope image. Further, the output signal of the waveform conversion circuit 23 is sent to sample and hold circuits 27a to 27x. In this sample and hold circuit, when a sample pulse from the timing generation circuit 26 comes, the output signal of the waveform conversion circuit 23 is sampled, and the voltage sampled at this time is held until the next sample pulse comes. The timings of the sample pulses sent from the timing circuit 26 to the sample and hold circuits 27a, 27b, 27c to 27x are shifted at equal intervals. For this reason, the sample hold circuit 27a is
A voltage corresponding to the brightness and darkness of point a of the enlarged microscope image 21 is maintained. Similarly, sample hold circuits 27b, 27
c...27x is b of the enlarged microscope image 21, respectively.
Point, C point... hold a voltage corresponding to the brightness of point x. Light emitting diode lighting circuit 28a, 28b, 2
8c, . . . 28× are sample and hold circuits 27a, 27
Light emitting diode blocks 29a, 29b, 29c depending on the magnitude of the output voltage of b, 27c, ...27x
, . . . controls the number of light-emitting diodes in each of 29×. Next, four display forms of the light emitting diode block will be explained with reference to FIG. Light emitting diode blocks 29a, 29
b, 29c, . . . 29x are arranged sequentially from left to right as shown in FIG. In each of these light emitting diode blocks, a plurality of light emitting diodes (1q in the figure) are sequentially arranged from bottom to top. These light emitting diodes are blinked by an output signal of a light emitting diode lighting circuit. Now, attention is paid to the light emitting diode block 29a. The table below shows an example of how the light emitting diode is lit when the input voltage of the light emitting diode lighting circuit 28a changes from 0 volts to 1.2 volts. As is clear from this table, as the input voltage of the light emitting diode lighting circuit increases, the number of light emitting diodes that light up increases.

In other words, from the number of light-emitting diodes that are lit, it is possible to know the magnitude of the input voltage to the light-emitting diode lighting circuit, that is, the degree of brightness at a certain point within the field of view of the microscope (point a in the above explanation). As is clear from the above explanation, points a, b, c, . . . in the enlarged microscope image 21 in FIG.
. . . The degree of brightness at point x corresponds to the number of lighted light emitting diodes in each of the light emitting diode blocks 29a, 29b, 29c, . . . 29× in FIG. 5. Therefore, the brightness and the uniformity of brightness within the field of view of the microscope can be accurately monitored from the lighting status of the light emitting diodes shown in FIG. Next, an embodiment of the present invention is shown in FIG.

The embodiment shown in FIG. 6 is a simplified version of the embodiment shown in FIG. 4, and is similar in many respects, so the explanation will focus on the differences.

In FIG. 6, the sample and hold circuit and the light emitting diode lighting circuit are reduced to just one set, 27a and 28a. This is intended to operate basically the same as the plurality of circuits shown in FIG. 4 by operating this one set of circuits in a time-division manner. Furthermore, the number of light emitting diode blocks has been reduced to three sets, 29a to 29c. This is because the brightness of the visual field and the uniformity of brightness can both be monitored under the minimum conditions by displaying the brightness levels at three locations, the center and both ends of the enlarged microscope image. That is, this embodiment attempts to realize the object of the present invention with the simplest configuration. In the embodiment shown in FIG. 6, the timing generation circuit 26 is slightly modified, and the signals at three points a, b, and c of the enlarged microscope image 21 are repeatedly sampled and held one by one for each scan of the one-dimensional image sensor. The circuit 27a samples and holds the sample.

Further, the timing generation circuit 26 controls the light emitting diode blocks 29a, 29b, 2 according to the sampled signal.
9c can be turned on. In other words, now a
If the signal at the point is sampled, only the light emitting diode block 29a is set to a lighting enabled state, and the other light emitting diode blocks 29b and 29c are set to a lighting disabled state.
Next, when the signal at point b is sampled, only the light emitting diode block 29b is similarly enabled to light up.
Furthermore, when the signal at point c is sampled, only the light-emitting diode block 29c is enabled to light up. If you repeat this operation sequentially, the number of lights will normally reach 1000.
times/second, so to the human eye, the three light emitting diode blocks appear to be constantly lit due to afterimages. In this way, the embodiment shown in FIG. 6 can achieve the object of the present invention, although it has a simple configuration. In each of the above embodiments, each light emitting diode block displays the brightness of each layer in the form of a graph in response to an electrical signal corresponding to the brightness of each layer detected by the image sensor. However, it is of course possible to turn on only the brightness peak position corresponding to each layer and display it on a line graph.

Further, FIG. 7 shows another embodiment.

In the embodiment shown in FIG. 7, the brightness within the field of view of the microscope is not displayed two-dimensionally as in the previous two examples, but is displayed using a voltage indicator such as a meter.

Also, these voltage indicators do not display the brightness of three or more points in the enlarged microscope image as in the previous example, but instead display the brightness of the center, the brightness of the center, and the brightness of the left edge. Displays three types of data: the difference in brightness between the center part and the right end part. Timing generation circuit 26 in FIG. 7 performs the same operation as the timing generation circuit in FIG. 4.

As a result, sample hold circuits 27a, 27b, 27
The output signal c corresponds to the brightness of each point a, b, and c of the enlarged microscope image 21. Sample and hold circuits 27a, 27
The output voltage of b is input to the differential amplifier 30a. Differential amplifier 30a determines the difference in voltage between the output voltages of sample and hold circuits 27a and 27b, and sends this to voltage indicator 31a. As a result, the voltage indicator 81a is a of the enlarged microscope image 21.
This represents the difference in brightness between point and point b. Similarly, the voltage indicator 31c indicates the difference in brightness between point c and point b in the microscope field of view 21. Further, the voltage display 31b indicates the brightness at point b. In this manner, in the embodiment of FIG. 7, the voltage indicator 31b represents the brightness within the field of view of the microscope, and the voltage indicators 31a and 31c represent the uniformity of the brightness. In each of the above embodiments, the brightness level is displayed by directly using the output of a one-dimensional image sensor that has been conventionally arranged to detect brightness within the field of view of a microscope. , the configuration is extremely simple.

Note that the photoelectric conversion means that detects the brightness at multiple positions within the field of view of the microscope and converts it into an electrical signal is not limited to the one-dimensional image sensor described above, but only detects the brightness of a predetermined point within the field of view of the microscope. Of course, it is also possible to arrange a plurality of photoelectric sensors within the field of view of the microscope, or to provide a one-dimensional image sensor different from the conventional one-dimensional image sensor for displaying brightness and darkness levels. FIG. 8 shows another embodiment of the present invention.

In this embodiment, two one-dimensional image sensors 41 and 42 are installed within the enlarged microscope image 21.

The output signals of these one-dimensional image sensors are amplified by an amplifier 21 and an amplifier 22, respectively, and then a signal switch 3
2. The signal switch 32 selects one of these two signals and sends it to the waveform conversion circuit 23. Here, a waveform conversion circuit 23, a voltage comparator 24, a focus signal generation circuit 25, a microscope control circuit 6, a sample hold circuit 2
7a have the same functions and functions as those with the same numbers in FIG. 4, so a description thereof will be omitted. Reference numeral 33 includes an analog-to-digital converter, which converts the output signal of the sample and hold circuit 27a into a corresponding digital signal.

This digital signal is sent to the computer of the leukocyte classification and control section 9, where it is arithmetic-processed and then displayed on the data display section 11. The operation of this embodiment will be described below, focusing on the differences from other embodiments.

The computer of the control unit 9 selects the signal of one of the two one-dimensional image sensors using the signal switch 32.

Next, the computer issues a command to the timing generation circuit 26 to generate the signal at the specified point on the enlarged microscope image.
After that, the analog-to-digital converter 33 is operated to convert the held voltage into a digital signal, and this data is taken in. This series of operations is performed for each point on the image sensor of the enlarged image of the microscope, and the data at each point is displayed on the CRT (cathode ray tube) of the data display section 11, with the horizontal axis representing the position on the image sensor and the vertical axis representing the position on the image sensor. Two-dimensional display is performed by taking the magnitude of the digital signal, that is, the brightness of each point in the enlarged microscope image.

As a result, the display on the CRT is as shown in the previous embodiment (Fig. 4).
The brightness and uniformity of brightness within the field of view of the microscope can be easily monitored.

Furthermore, since this embodiment has two one-dimensional image sensors, by displaying these two data in a superimposed manner, it is also possible to monitor the uniformity of brightness in the vertical direction within the field of view of the microscope. Further, in this embodiment, an alarm can be automatically issued under computer control when the brightness within the field of view of the microscope fluctuates more than permissible due to lamp life or the like.

It is also possible to automatically issue an alarm when the uniformity of brightness within the field of view deteriorates beyond tolerance. In each of the above embodiments, the present invention is equipped with a television camera that converts an enlarged image of the image processing object into an electrical two-dimensional image signal after stopping the image processing object at a predetermined position within the microscope. Although the present invention is applied to an image processing device, the scope of application of the present invention is not limited thereto, and can similarly be applied to an image processing device that only has a one-dimensional image sensor and only performs positioning of an object to be image processed. The applicability is clear.

As explained in detail above, according to the present invention, it is possible to accurately monitor the brightness and contrast in the field of view of the microscope,
Moreover, it has the excellent effect that failures in the optical system can be detected quickly and it becomes possible to realize an accurate image processing device.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams showing the relationship between each layer in the field of view of a microscope and the output of a one-dimensional image sensor. FIG. 3 is a block diagram showing the configuration of the first embodiment of the image processing device according to the present invention applied to a white blood cell classification device, and FIG. , a block diagram showing a specific example of the configuration of the optical system monitor section in the embodiment, FIG. 5 is a front view showing a specific example of the structure of the light emitting diode block in the embodiment, FIG. FIG. 7 is a block diagram showing the configuration of the second embodiment of the image processing device according to the second embodiment, FIG. 7 is a block diagram showing the configuration of the third embodiment, and FIG. 8 is the same block diagram showing the configuration of the fourth embodiment. It is a block diagram. 2... Microscope, 4, 41, 42... One-dimensional image sensor, 5... White blood cell detection and focus adjustment circuit, 6...
・Microscope control circuit, 7... Two-dimensional image sensor, 8
... Feature extraction circuit, 9... White blood cell classification and control section,
10...Printer, 11...Data display section, 12.
...Data file section, 13...Optical system monitor section, 2
DESCRIPTION OF SYMBOLS 1... Microscope enlarged image, 22, 221, 222... Amplifier, 23... Waveform conversion circuit, 24... Voltage comparator, 25... Focus signal generation circuit, 26... Timing generation circuit , 27a-27x...sample hold circuit, 28a-28x...light-emitting diode lighting circuit, 29
a~29×...Light emitting diode block, 30a, 3
0b. ...Differential amplifier, 31a to 31c...Voltage indicator, 32...Signal switch, 33...Analog-digital converter. Figure 2, Figure 3, Figure 4, Figure 5, Figure 8, Figure 8.

Claims (1)

[Scope of Claims] 1. A microscope that magnifies an optical image of an object to be image processed, one or more first photoelectric conversion means that converts the magnified image of the microscope into an electrical image signal, and the first photoelectric conversion means that converts the enlarged image of the microscope into an electrical image signal. An image processing device comprising a signal processing means for processing an electrical image signal output from the conversion means, a second photoelectric conversion means for detecting brightness at a plurality of positions within a field of view of a microscope and converting the detected brightness into an electrical signal; Second
a brightness/darkness level display means for displaying the brightness level within the microscope field of view according to the electrical signal output from the photoelectric conversion means; 1. An image processing device comprising: an alarm means for outputting an alarm signal when the difference in brightness falls outside of an allowable range. 2. The first photoelectric conversion means is also used as the second photoelectric conversion means, and the brightness level display means displays at least a part of the electrical image signal output from the first photoelectric conversion means. An image processing apparatus according to claim 1. 3. The second photoelectric conversion means is a plurality of one-dimensional image sensors that detect the brightness of each position on a plurality of lines within the field of view of the microscope and converts it into an electrical signal, and the brightness level display means 2. The image processing device according to claim 1, wherein the output signal of the one-dimensional image sensor is superimposed or switched and displayed. 4. The image processing apparatus according to claim 1, wherein the brightness level display means displays an absolute value corresponding to brightness at each of a plurality of positions. 5. The brightness level display means is configured to display an absolute value corresponding to the brightness of a predetermined position among each of the plurality of positions and a relative value corresponding to the brightness difference of other positions when the predetermined position is used as a reference. An image processing apparatus according to claim 1.