JP2014149484A - Imaging system and method for controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology for obtaining an image focused on an object under consideration in a subject in the case of photographing the subject at a plurality of focal positions in an optical axis direction.SOLUTION: An imaging system includes: setting means having a function for photographing a subject multiple times while changing a focal position in an optical axis direction to obtain images for a plurality of layers in the subject, which sets information for specifying an object under consideration among a plurality of types of objects included in the subject; and control means for adjusting the focal position in the optical axis direction in the case of photographing each layer to obtain an image focused on the object in each layer on the basis of the information set by the setting means.

Description

  The present invention relates to an imaging system capable of acquiring images of a plurality of layers in a subject by performing imaging a plurality of times while changing a focal position, and more particularly to a system for digitizing a microscopic image of a pathological specimen.

  For the purpose of diagnosing a disease and investigating the cause, there is an examination called a pathological examination in which a specimen such as an organ, tissue, or cell collected by surgery or examination is diagnosed using a microscope. In recent years, a system for taking a microscopic image of a pathological specimen with a high-sensitivity digital imaging apparatus and observing and diagnosing the obtained high-resolution digital image on a display has been put into practical use, and the needs thereof are increasing. Such a system is called a virtual slide system or a digital pathology system.

  One type of pathology test is a test called cytology. In cytodiagnosis, a pathological specimen is prepared by staining a cell that has been peeled off from a lesion and mixed with sputum or urine, or a cell collected by inserting a needle into the lesion and sucking it. Since such a pathological specimen has a certain thickness, it is necessary to observe and inspect not only the specimen surface but also various depths in the optical axis direction (thickness direction or depth direction).

  There is known a method of acquiring a plurality of images at different depths in a sample by photographing the sample a plurality of times while gradually shifting the focal position in the optical axis direction. This method is called a Z stack, and the obtained image group is also called a Z stack image, and individual images are also called layer images. In Patent Document 1, in order to appropriately set the focal movement pitch in the Z stack, the focal movement pitch is determined from the wavelength of light used for specimen observation and the numerical aperture of the objective lens of the microscope. Is disclosed.

JP 2002-258163 A

  Some specimens have been iron-stained to diagnose the cause of microcytic hypochromic anemia (the pathology of iron metabolism). In this specimen, a small amount of iron components stained in blue are present in a large amount of protein particles stained in red. In this specimen, the iron component stained in blue is an object to be noticed in diagnosis (hereinafter referred to as a diagnostic object) and needs to be observed in detail. However, since the iron component which is a diagnostic object is very small, there is a case where the iron component does not enter the in-focus range when imaging is performed while moving the focal position at a constant pitch as in the method of Patent Document 1. . Also, even if you try to search for the focus position using the autofocus function, it will be difficult to identify the position where the target iron component is focused because the protein particles that are present in large amounts in the field of view will be focused. .

  As described above, when a specimen that includes a plurality of types of objects and has a small proportion of the diagnostic object to be noticed is a subject, if the focal position is moved at a constant pitch, the diagnostic object is focused. There is a high possibility that an image that is not (the diagnostic object is blurred) will be obtained. Further, there is a problem that it is difficult to focus on a target diagnostic object even if autofocus is executed.

  In view of such problems, the present invention provides a technique for obtaining an image focused on an object to be noted in a subject when the subject is photographed at a plurality of focal positions in the optical axis direction. The purpose is to provide.

  A first aspect of the present invention is an imaging system that acquires images of a plurality of layers in the subject by photographing the subject a plurality of times while changing the focal position in the optical axis direction, and includes a plurality of the subjects included in the subject Based on the setting means for setting information for identifying the target object of interest among the types of objects and the information set by the setting means, an image focused on the target object in each layer is obtained. As described above, the imaging system includes control means for adjusting the focal position in the optical axis direction when each layer is imaged.

  According to a second aspect of the present invention, there is provided an imaging system control method for acquiring images of a plurality of layers in a subject by photographing the subject a plurality of times while changing a focal position in an optical axis direction. A setting step for setting information for identifying a target object of interest among a plurality of types of included objects, and the target in each layer is focused based on the information set by the setting step And a control step of adjusting a focal position in the optical axis direction when each layer is photographed so that an image is obtained.

  According to the present invention, when a subject is photographed at a plurality of focal positions in the optical axis direction, it is possible to obtain an image focused on an object to be noted in the subject.

Configuration diagram of imaging system Block diagram of microscope control device Diagram showing an example of object placement in a specimen Flowchart of cover glass and slide glass interval calculation process The figure which shows the example of imaging reference width and imaging reference position Microscope image acquisition process flowchart The figure which shows the example of the adjusted focus position Table showing numerical examples of imaging reference position and actual imaging position in FIG.

The present invention relates to an imaging system having a function (Z stack function) for acquiring images at different depth positions (layers) in a subject by photographing the subject a plurality of times while changing the focal position in the optical axis direction, and control thereof. It is about the method. Conventionally, the focal position of each layer is set at an equal interval, but in the present invention, the focal position of each layer is appropriately adjusted so that a desired object is focused on each layer. At this time, information for specifying an object to be focused is given to the system in advance so that focusing on each layer can be performed easily and accurately. The technique according to the present invention can be preferably applied to a system for digitizing a microscopic image of a subject such as a pathological specimen, various inspection systems, and an analysis system.
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

(Overall system configuration)
FIG. 1 is a diagram showing an overall configuration of an imaging system according to an embodiment of the present invention. This system includes a microscope 100, an imaging device 110, a computer 120, a display (display device) 130, and a microscope control device 200.

  The microscope 100 is a device that enlarges an optical image of the specimen 103 as a subject and guides the optical image to the imaging device 110. The microscope 100 includes a stage 102 that supports a specimen 103 and an objective lens (optical system) 101. The microscope 100 also includes an eyepiece (not shown), an illumination device that irradiates the specimen 103 with light, and an electric stage driving device that drives the stage 102. The microscope 100 is connected to the microscope control device 200 by, for example, a USB interface, and is controlled by a control signal from the microscope control device 200.

The objective lens 101 is a lens facing the sample 103 and forms an intermediate real image of the sample 103. An eyepiece lens (not shown) enlarges the intermediate real image formed by the objective lens 101 and forms an image on the image plane of the imaging device 110.
The stage 102 is moved in three axial directions, ie, a plane direction (XY direction) and an optical axis direction (Z direction) by an electric stage driving device (not shown). The position (XY position) on the plane of the specimen area observed with the microscope 100 changes due to the movement of the stage 102 in the plane direction, and the focal position on the optical axis of the specimen 103 observed with the microscope 100 due to the movement in the optical axis direction. Changes.
The specimen 103 is a preparation prepared by, for example, placing blood stained with a plurality of cells on a slide glass and covering it with a cover glass.

  The imaging device 110 is a device that takes an optical image of the specimen 103 magnified by the microscope 100 and generates / outputs digital image data. The imaging device 110 can be configured by an image sensor such as a CCD or a CMOS, for example. The imaging device 110 is connected to the microscope control device 200 by, for example, a USB interface. Digital image data output from the imaging device 110 is sent to the microscope control device 200.

  The computer 120 is connected to the microscope control device 200 by, for example, a USB interface. The computer 120 includes input devices such as a keyboard and a mouse (not shown). The computer 120 provides a GUI (Graphical User Interface) for setting the number of imaging layers and setting a diagnosis target color, which will be described later, to the microscope control apparatus 200. When the user operates the keyboard or mouse to change the setting through the GUI, the changed setting data is sent to the microscope control apparatus 200.

  The number of imaging layers is the number of layer images taken from one subject in the Z stack (the number of focal positions set for one subject). As a GUI for setting the number of imaging layers, for example, a desired number of layers may be selected from a list of numbers such as “5/10/15”, or an arbitrary number may be input. Alternatively, the number of layers required may be calculated from the thickness and pitch of the subject by inputting the pitch (interval between layers).

  The diagnosis target color is information representing a color range that can be taken by a target object (diagnosis target object). This information is used to specify the portion of the diagnostic object based on the color information from the subject image when a plurality of types of objects are mixed in the subject. As a GUI for setting a diagnosis target color, for example, a type of staining applied to a diagnosis target may be selected, or a desired color or color range may be specified on a sample image or a hue pattern Alternatively, a desired color or color range may be selected from the list.

  The computer 120 may be configured by a general-purpose personal computer or a mobile terminal such as a tablet terminal or a smart phone. Further, the function of the computer 120 may be incorporated (integrated) in the microscope control apparatus 200.

The display 130 is connected to the microscope control device 200 by, for example, DVI (Digital Visual Interface). The display 130 receives a microscope image from the microscope control apparatus 200 and displays it on the screen. The function of displaying this image on the screen is provided by a viewer program executed by the microscope control device 200 or the computer 120.

  The microscope control device 200 is connected to the microscope 100, the imaging device 110, the computer 120, and the display 130, respectively. The microscope control device 200 is a device that functions to control the microscope 100 and the imaging device 110 in accordance with settings from the computer 120 to acquire a microscope image focused on the diagnostic object and display it on the display 130. . Details of the microscope control apparatus 200 will be described in detail in the description of FIG.

(Microscope control device)
FIG. 2 is a block diagram illustrating a functional configuration of the microscope control apparatus 200 according to the present embodiment. The microscope control device 200 includes a video input unit 201, a target color setting unit 202, a target color filter unit 203, an imaging layer number setting unit 204, an imaging position adjustment unit 205, an image data storage unit 206, and a focus control unit 207. These functions may be realized by a program, or a part or all of them may be realized by a dedicated circuit. For example, the microscope control apparatus 200 may be configured with a general-purpose computer and a program, or may be configured with an FPGA or an ASIC. Further, as described above, the microscope control apparatus 200 and the computer 120 can be integrated.

The image input unit 201 receives an image of a sample photographed by the imaging device 110. The input image is sent to the target color filter unit 203, the focus control unit 207, and the image data storage unit 206, respectively.
The target color setting unit 202 receives data of the diagnosis target color set by the user from the computer 120 and sends the data to the target color filter unit 203.

  The target color filter unit 203 performs a filtering process on the specimen image (original image) acquired from the video input unit 201 according to the diagnostic target color data received from the target color setting unit 202, and the filtered image is obtained. Generate. The filtered image is sent to the focus control unit 207. As mentioned above, there are many cases where objects of various hues are mixed in addition to the diagnostic object, as described above, the original image of the specimen can be used for focusing by autofocus using the original image. It is difficult to focus on the diagnostic object. Therefore, for example, the target color filter unit 203 leaves only the part of the color range represented by the diagnosis target color (that is, the color range that can be taken by the diagnosis target object) from the original image, and the part outside the color range is predetermined. Is replaced with a pixel value (for example, white or black). Thereby, an image in which a portion of the diagnostic object is extracted or emphasized can be obtained. A focus control unit 207, which will be described later, performs focusing processing using the image filtered by the target color filter unit 203 (not the original image).

The imaging layer number setting unit 204 receives data on the number of imaging layers set by the user from the computer 120 and sends the data to the focus control unit 207.
The imaging position adjustment unit 205 generates a stage position movement control signal and outputs it to the microscope 100 in order to move the stage to the imaging position designated by the focus control unit 207.

  When there is an image data recording instruction from the focus control unit 207, the image data storage unit 206 stores the image acquired from the video input unit 201 in a storage medium. As the storage medium, any type of storage medium such as an internal hard disk, an external hard disk, a network storage, an SSD, a USB memory, a flash memory, a CD-ROM, or a DVD-ROM may be used.

  The focus control unit 207 is a functional block that performs control for adjusting the focal position in the optical axis direction when each layer is imaged so that an image focused on the diagnostic object is obtained in each layer. The focus control unit 207 also has a function of sending an image data recording instruction to the image data storage unit 206 and a function of sending an imaging position to the imaging position adjustment unit 205. The imaging position is position information for defining the focal position in the optical axis direction of the microscope 100 (objective lens 101) when photographing. Although the focal position itself may be the imaging position, in the present embodiment, in consideration of the focal depth of the objective lens 101 (also referred to as depth of field), the upper end of the focal depth centered on the focal position (closer to the objective lens 101). The position of the side end) is designated as the imaging position. Detailed processing of the focus control unit 207 will be described later.

(Sample example)
FIG. 3 is a cross-sectional view showing an example of a pathological specimen, and shows an example of an object arrangement in the specimen. The specimen is a preparation formed by placing a sample such as a cell or a tissue piece on the slide glass 301b and fixing the cover glass 301a. In the sample between the slide glass 301b and the cover glass 301a, objects (diagnosis target objects) 302a, 302b, and 302c to be noted in the diagnosis and other objects 303a, 303b, and 303c that are not targets for diagnosis are mixed. ing. In the present embodiment, it is assumed that the diagnosis objects 302a, 302b, and 302c are dyed in different hues (color ranges) such as blue and the other objects 303a, 303b, and 303c are red.

(Calculation of specimen thickness)
FIG. 4 is a flowchart of a process for calculating the distance between the cover glass and the slide glass. This process is executed by the focus control unit 207 of the microscope control apparatus 200. First, the focus control unit 207 sends a movement instruction to the imaging position adjustment unit 205, moves the stage 102 of the microscope 100 to a position farthest from the objective lens 101 (initial position) (S401), and then moves the stage 102 to the objective lens 101. Move to the side by a predetermined distance (S402). An image photographed by the imaging device 110 is taken into the focus control unit 207 via the video input unit 201. The focus control unit 207 uses the acquired image to determine whether or not the lower surface of the cover glass 301a is in focus using the contrast autofocus function (S403). The processes in S402 and S403 are repeated until the lower surface of the cover glass 301a is detected.

  After the lower surface of the cover glass 301a is detected (S403; Yes), the focus control unit 207 similarly performs a process of detecting the upper surface of the slide glass 301b while moving the stage 102 by a predetermined distance (S404). (S405). The upper surface of the slide glass 301b is also detected using the autofocus function.

  When the position of the lower surface of the cover glass 301a and the position of the upper surface of the slide glass 301b are specified by the above processing, the focus control unit 207 calculates the difference between the positions of the cover glass 301a and the slide glass 301b. The interval is obtained (S406). This interval corresponds to the thickness of the specimen, that is, the imaging range in the optical axis direction. In this embodiment, the distance between the cover glass and the slide glass is used as an example of the imaging range in the optical axis direction.For example, the range in which cells in the preparation exist or an arbitrary range in the preparation is used as the optical axis. A shooting range in the direction may be used.

(Focus position adjustment and image acquisition)
Next, the focus position adjustment and microscope image acquisition processing will be described in detail with reference to the flowchart of FIG.
First, the user operates the computer 120 to set a diagnosis target color (color range that can be taken by the diagnosis target) and the number of imaging layers (S801, S802). Data on the set diagnosis target color and the number of imaging layers is sent to the focus control unit 207.

ここで、光の波長λとしては、顕微鏡１００の照明装置の光源の波長を用いてもよいが、好ましくは、診断対象物の色（診断対象色）の波長を用いると良い。診断対象物の色に応じた焦点深度を用いることで、後段の焦点位置の探索精度を向上することができる。例えば、波長が約０．４６５μｍの青色に染色された診断対象物を、開口数ＮＡが０．６５の４０倍対物レンズで観察する場合、図５に示すように、焦点深度７０２は約０．５５μｍとなる。 Next, the focus control unit 207 calculates an interval (an imaging range in the optical axis direction) between the cover glass 301a and the slide glass 302b by the process described with reference to the flowchart of FIG. 4 (S803). Further, the focus control unit 207 calculates the depth of focus on the subject side of the objective lens 101 from the diagnosis target color data and the parameter (numerical aperture) of the objective lens 101 of the microscope 100 (S804). The depth of focus of a lens is a range that is in focus within a range observed through a lens, and is also called a depth of field. The depth of focus can be calculated by the following formula.

Here, as the wavelength λ of the light, the wavelength of the light source of the illumination device of the microscope 100 may be used, but the wavelength of the color of the diagnostic object (diagnostic object color) is preferably used. By using the depth of focus according to the color of the diagnostic object, it is possible to improve the accuracy of searching for the focal position at the subsequent stage. For example, when a diagnostic object stained in blue having a wavelength of about 0.465 μm is observed with a 40 × objective lens having a numerical aperture NA of 0.65, as shown in FIG. 55 μm.

図５の例では、カバーガラスとスライドガラスの間隔（光軸方向の撮影範囲）７０１が１０μｍ、撮像レイヤー数が５であるため、撮像基準幅７０３は２μｍである。 The focus control unit 207 calculates an imaging reference width from the number of imaging layers acquired in S802 and the imaging range in the optical axis direction obtained in S803 (S804). The imaging reference width is a reference pitch of the focal position, and is obtained by the following formula.

In the example of FIG. 5, since the distance between the cover glass and the slide glass (photographing range in the optical axis direction) 701 is 10 μm and the number of imaging layers is 5, the imaging reference width 703 is 2 μm.

  Further, the focus control unit 207 sets the imaging reference position of each layer from the imaging reference width 703, the number of imaging layers, the position of the lower surface of the cover glass, and the like (S804). The imaging reference position is a reference value (default value) of the imaging position when shooting the layer. In the example of FIG. 5, since the number of imaging layers is 5, five imaging reference positions 705 to 709 are set for each of the five layers. As shown in the figure, the imaging reference position 705 of the first imaged layer is set to the position of the lower surface of the cover glass, which is the upper end of the imaging range, and is also called the imaging start reference position. The second and subsequent imaging reference positions 706 to 709 are arranged at equal intervals every imaging reference width 703.

  Further, the focus control unit 207 calculates a search range 704, which is a range for searching for a focus position in S808 described later, from the imaging reference width 703 and the focal depth 702. Specifically, the search range 704 is a width obtained by subtracting the focal depth 702 from the imaging reference width 703. In the example of FIG. 5, since the imaging reference width 703 is 2 μm and the focal depth 702 is 0.55 μm, the search range 704 is 1.45 μm. Thus, by limiting the search range 704 in relation to the depth of focus, useless searches can be eliminated and processing time can be shortened.

Subsequently, the focus control unit 207 sends an imaging start reference position 705 to the imaging position adjustment unit 205.
To move the stage 102 of the microscope 100 to the imaging start reference position 705 (S805). Then, the focus control unit 207 sends an image data recording instruction to the image data storage unit 206, and records an image at the imaging start reference position 705 (S806).

  The focus control unit 207 compares the imaging reference width 703 that is an interval between the adjacent imaging reference positions 706 and the focal depth 702 of the lens, and when the imaging reference width 703 is larger than the focal depth 702 (S807; Yes). The focus position search process is performed by the autofocus function. Specifically, the focus control unit 207 evaluates the contrast of the image while gradually moving the imaging position downward from the imaging reference position, and a position where the contrast is maximized or maximized in the search range 704. Alternatively, a position where the contrast exceeds a predetermined threshold is detected. At this time, the focus control unit 207 performs contrast evaluation using the image filtered by the target color filter unit 203 instead of the original image acquired from the video input unit 201. As a result, only the contrast of the portion of the diagnostic object in the image can be evaluated, so that the position where the diagnostic object is in focus can be detected with high accuracy.

  When a position where an image focused on the diagnostic object is obtained is detected (S809; Yes), the focus control unit 207 determines the position at that time as the imaging position (focus position) of the layer, An image data recording instruction is sent to the image data storage unit 206. As a result, the image shot at the appropriate image pickup position (focus position) after adjustment is overwritten and recorded on the image shot at the image pickup reference position (S810).

  When the imaging reference width 703 is equal to or smaller than the depth of focus (S807; No), the focus position search process in S808 to S810 is not performed. This is because in the image captured at the imaging reference position (the image recorded in S806), since all the areas within the imaging reference width 702 are in focus, it is not necessary to adjust the focal position. As described above, by determining whether or not the focus position search process is necessary according to the relationship between the imaging reference width and the focal depth in S807, unnecessary processing can be omitted, and the processing efficiency of the entire system can be improved. it can.

  In S809, if the position where the diagnostic object is focused cannot be detected, the process proceeds to S811. In other words, the focus position is not adjusted, and an image shot and recorded at the corresponding imaging reference position is used as it is.

  When all the imagings for the number of layers set by the user have been executed (S811; Yes), the process ends. When there are remaining layers to be imaged (S811; No), the process moves to the imaging reference position of the next layer. In step S812, the processing from step S806 is performed again.

  In the present embodiment, the captured image at the first in-focus position found in the search range 704 is recorded. However, as another method, the entire search range 704 is searched and a plurality of in-focus positions are obtained. If found, all of the captured images may be recorded. As another method, when a plurality of in-focus positions are found by searching the entire search range 704, the contrast at each position is compared, and a captured image at the position where the contrast is maximum is recorded. You may make it do.

  FIG. 7 shows an example of the adjustment result of the imaging position (focus position) by the above method. FIG. 7 shows the relationship between the imaging reference position and the actual imaging position when the sample shown in FIG. 5 is imaged. Reference numerals 901a, 902a, 903a, 904a, and 905a indicate imaging reference positions of the five layers. In contrast, reference numerals 901b, 902b, 903b, 904b, and 905b indicate actual imaging positions when each layer is imaged. It can be seen that the imaging positions are adjusted for the second layer and the fourth layer.

  FIG. 8 is a table showing numerical examples of the imaging reference position and the actual imaging position in FIG. In the first, third, and fifth layers, since the position where the diagnostic object is focused cannot be detected, the imaging reference position matches the actual imaging position. In the second layer, the actual imaging position is 2.50 μm with respect to the imaging reference position of 2 μm, and the diagnostic object is focused at the position moved by 0.50 μm, and the captured image at that position is recorded. It shows that. Similarly, in the fourth layer, it is shown that the image is focused at the position of 7.10 μm moved by 1.10 μm with respect to the imaging reference position of 6 μm, and the captured image at that position is recorded.

  According to the configuration of the present embodiment described above, information for specifying the diagnostic object is set by the user, and the focal position of each layer (so that an image focused on the diagnostic object is obtained in each layer ( Adjust the (imaging position). Therefore, an image suitable for diagnosis can be obtained even when the subject includes many objects other than the diagnostic object. In the present embodiment, focusing on the difference in hue due to staining, the portion of the color range of the diagnostic object is extracted by filtering, and the focus position is searched using the image. It is possible to accurately and automatically perform in-focus determination for. Furthermore, by narrowing down the focus position search range based on the focal depth of the lens, it is possible to prevent useless search processing from occurring, so that the overall processing speed can be improved.

  The above embodiment is merely a specific example of the present invention, and is not intended to limit the scope of the present invention. For example, in the above-described embodiment, contrast detection type autofocus (a method of searching for a position where the contrast of an image increases) is used, but the focus position may be searched by other methods. For example, phase difference detection type autofocus may be used. In the above embodiment, the target object to be noticed is specified by the color range, but the target object may be specified by other information. For example, when there is a feature in the shape, size, position, etc., it is also possible to specify an object to be noted with such information. Moreover, although the microscope system used for pathological diagnosis was illustrated in the said embodiment, you may use the image image | photographed with the general digital camera instead of a microscope depending on the target of a test | inspection or observation.

100: Microscope, 102: Specimen (Subject), 110: Imaging device, 120: Computer, 200: Microscope control device

Claims (16)

An imaging system for acquiring images of a plurality of layers in the subject by photographing the subject a plurality of times while changing a focal position in an optical axis direction,
Setting means for setting information for specifying a target object to be noted among a plurality of types of objects included in the subject;
Control means for adjusting the focal position in the optical axis direction when shooting each layer so that an image focused on the object is obtained in each layer based on the information set by the setting means; ,
An imaging system comprising:   2. The imaging system according to claim 1, wherein the information for specifying the object is information representing a color range that the object can take. Color filter means for performing a filtering process for extracting a portion of the color range on an image obtained by photographing the subject;
The control means performs the focusing on the object using the image filtered by the color filter means when adjusting the focal position so that an image focused on the object is obtained. The imaging system according to claim 2, wherein: The control means includes
A reference position in the optical axis direction is set for each of the plurality of layers,
For each layer, the focus position of each layer is determined by searching a focus position at which an image focused on the object is obtained within a predetermined search range based on the corresponding reference position. The imaging system according to any one of claims 1 to 3, wherein the imaging system is characterized in that The control means sets the focus position of the layer at a position corresponding to the reference position when there is no position where an image focused on the object is obtained in the predetermined search range. The imaging system according to claim 4, wherein the imaging system is set. 6. The imaging system according to claim 4, wherein the width of the predetermined search range is a width obtained by subtracting a depth of focus on the subject side from an interval between reference positions with adjacent layers. The control means compares the distance between the reference positions of adjacent layers and the depth of focus on the subject side,
When the interval between the reference positions is larger than the depth of focus, a process for searching for a focal position where an image focused on the object is obtained within the predetermined search range is performed.
The focus position is set at a position corresponding to the reference position without performing a process of searching for the focus position when the interval between the reference positions is equal to or less than the depth of focus. The imaging system of any one of them. A microscope, and an imaging unit that captures an image of the subject magnified by the microscope,
The imaging system according to claim 1, wherein the subject is a stained specimen. An imaging system control method for acquiring images of a plurality of layers in a subject by photographing the subject a plurality of times while changing a focal position in an optical axis direction,
A setting step for setting information for identifying an object to be noted among a plurality of types of objects included in the subject;
A control step of adjusting the focal position in the optical axis direction when shooting each layer based on the information set in the setting step so that an image focused on the object is obtained in each layer; ,
A control method for an imaging system, comprising:   The method for controlling an imaging system according to claim 9, wherein the information for specifying the object is information representing a color range that the object can take. The imaging system has color filter means for performing filter processing for extracting a portion of the color range for an image obtained by photographing the subject,
In the control step, when the focus position is adjusted so that an image focused on the object is obtained, the object is focused using the image filtered by the color filter means. The method of controlling an imaging system according to claim 10, wherein In the control step,
A reference position in the optical axis direction is set for each of the plurality of layers,
For each layer, the focus position of each layer is determined by searching a focus position at which an image focused on the object is obtained within a predetermined search range based on the corresponding reference position. The method of controlling an imaging system according to any one of claims 9 to 11. In the control step, if there is no position where an image focused on the object is obtained in the predetermined search range, the focus position of the layer is set at a position corresponding to the reference position. The imaging system control method according to claim 12, wherein setting is performed. The imaging system control method according to claim 12 or 13, wherein the width of the predetermined search range is a width obtained by subtracting a depth of focus on the subject side from an interval of a reference position between adjacent layers. In the control step, the distance between the reference positions of adjacent layers and the depth of focus on the subject side are compared,
When the interval between the reference positions is larger than the depth of focus, a process for searching for a focal position where an image focused on the object is obtained within the predetermined search range is performed.
15. The focus position is set at a position corresponding to the reference position without performing a process of searching for the focus position when the interval between the reference positions is equal to or less than the depth of focus. The control method of the imaging system of any one of them. The imaging system includes a microscope and imaging means for capturing an image of the subject magnified by the microscope,
The method of controlling an imaging system according to claim 9, wherein the subject is a stained specimen.

Images