METHOD FOR SETTING ANALYSIS TARGET REGION BY EXTRACTING, FROM AN OBSERVED IMAGE DIVISIONAL AREAS HAVING A VALUE OF IMAGE CHARACTERISTIC QUANTITY WITHIN A VALUE RANGE

Abstract

A method for setting, within an observed image of a sample, an analysis target region that is a region on which an analysis is to be performed by an analyzer, the method including displaying the observed image of the sample on the display, dividing the observed image into a plurality of divisional areas, calculating a predetermined image characteristic quantity in each of the plurality of divisional areas, designating at least two of the divisional areas of the observed image displayed on the display, calculating a distribution of the values of the image characteristic quantity of the designated divisional areas, determining a value range of the image characteristic quantity for the divisional areas to be extracted as the analysis target region, based on the calculated distribution, and extracting from the observed image each of the plurality of divisional areas having a value of the image characteristic quantity within the value range.

Claims

1. A method for setting, within an observed image of a sample, an analysis target region that is a region on which an analysis is to be performed by an analyzer, the method including the steps of: displaying the observed image of the sample on the display; dividing the observed image into a plurality of divisional areas calculating a predetermined image characteristic quantity in each divisional area of the plurality of divisional areas; designating at least two of the divisional areas of the observed image displayed on the display; calculating a distribution of the values of the image characteristic quantity of the designated divisional areas determining a value range of the image characteristic quantity for the divisional areas to be extracted as the analysis target region, based on the calculated distribution; extracting from the observed image each divisional area of the plurality of divisional areas having a value of the image characteristic quantity within the value range; and displaying the observed image on the display with the analysis target region designated based on the divisional areas extracted.

2. The method for setting an analysis target region according to claim 1, wherein the values of the image characteristic quantity of the designated divisional areas are entirely or partially included in the value range.

3. The method for setting an analysis target region according to claim 1, wherein none of the values of the image characteristic quantity of the designated divisional areas is included in the value range.

4. The method for setting an analysis target region according to claim 1, wherein the at least two of the divisional areas are designated by drawing a line on the displayed observed image, through the at least two of the divisional areas.

5. The method for setting an analysis target region according to claim 1, wherein the value range is determined by statistically processing the distribution.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0023] FIG. 1 is a configuration diagram showing the main components of an infrared microscope as one embodiment of the present invention.

[0024] FIG. 2 is a flowchart showing the process of setting an analysis target region in the infrared microscope of the present embodiment.

[0025] FIG. 3 shows one example of the observed image displayed on the screen of a display unit.

[0026] FIG. 4 shows one example of the divisional areas defined for the observed image.

[0027] FIG. 5 shows a line specified by a user on the observed image.

[0028] FIG. 6 shows representative selected areas corresponding to the line specified by a user.

[0029] FIGS. 7A and 7B each illustrate the brightness distribution of the representative selected areas and a value range to be set for that brightness distribution.

[0030] FIG. 8 shows an analysis target region which has been set on the observed image.

[0031] FIG. 9 shows another example of the observed image displayed on the screen of the display unit, with a line specified by a user on the observed image.

[0032] FIG. 10 illustrates the brightness distribution of the representative selected areas corresponding to the line specified by the user and a value range to be set for that brightness distribution.

[0033] FIG. 11 shows analysis target regions which have been set on the observed image.

DESCRIPTION OF EMBODIMENTS

Embodiments

[0034] An infrared microscope as one embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing the main components of the infrared microscope of the present embodiment.

[0035] In FIG. 1, an infrared interferometer 1 includes an infrared source, fixed mirror, movable mirror, beam splitter and other devices. It emits an infrared interference light produced by an interference of infrared rays having different wavelengths. The infrared interference light is reflected by a half mirror 4 and cast onto a sample 3 placed on a movable stage 2. When the infrared interference light cast onto the sample 3 is reflected by the surface, the light undergoes absorption at one or more wavelengths (normally, at multiple wavelengths) specific to the substances present on that location. The infrared light reflected from the sample 3 passes through the half mirror 4 and reaches the aperture element 5, which admits only the reflected light coming from a specific region. This light is redirected by a reflection mirror 6 to an infrared detector 7, which receives and detects the light. Therefore, the infrared interference light arriving at the infrared detector 7 is reflective of the infrared absorption which occurs at the specific region in the sample 3.

[0036] The detection signal produced by the infrared detector 7 is sent to a data processor 10. In the data processor 10, a Fourier transform calculator 100 performs a Fourier transform process on the detection signal to obtain an infrared absorption spectrum showing the absorbance over a predetermined range of wavelengths. The spectrum data thus obtained is sent to a controller 11 and displayed on the screen of a display unit 13 connected to the controller 11. Meanwhile, visible light is emitted from a visible light source 8 and illuminates a large area on the sample 3. The visible light reflected from the sample 3 is introduced into a CCD camera 9. In the CCD camera 9, an observed image of the surface of the sample 3 is formed, and the data of the observed image are sent to the controller 11. Similarly to the spectrum data, the observed image data sent to the controller 11 are also displayed on the screen of the display unit 13. The area which is illuminated with the infrared interference light and on which the measurement of the reflected light is performed can be changed by appropriately operating the movable stage 2 and aperture element 5 under the command of the controller 11. The controller 11 also controls the operations of the infrared interferometer 1, visible light source 8 and other components.

[0037] The data processor 10 and controller 11 can be configured to achieve various functions (which will be described later) by executing, on a personal computer, a dedicated controlling and data-processing software program previously installed on the computer.

[0038] The system shown in FIG. 1 is configured to perform a reflective infrared measurement and reflective visible observation. The configuration may be changed so as to perform a transmissive infrared measurement and/or transmissive visible observation. It is also possible to include a mechanism for allowing users to visually and directly observe the sample surface through an eyepiece.

[0039] The process of setting an analysis target region from an observed image of a sample in the infrared microscope of the present embodiment is hereinafter described by means of the flowchart of FIG. 2.

[0040] After a sample 3 as a measurement target is placed on the movable stage 2, a visible image of the sample 3 is taken with the CCD camera 9. The obtained image data are sent to the controller 11, and the observed image as shown in FIG. 3 is displayed on the screen of the display unit 13 (Step S1). Furthermore, the controller 11 divides this observed image into a plurality of areas as shown in FIG. 4 (in the shown example, MxN areas) and calculates a characteristic quantity for each divisional area (Step S2). Each divisional area may consist of a single pixel or a set of neighboring pixels.

[0041] As for the herein calculated characteristic quantity, a pixel characteristic quantity or texture characteristic quantity can be used. The pixel characteristic quantity is the image information possessed by each individual pixel, such as the brightness, hue and saturation. The texture characteristic quantity is a numerical representation of texture components, such as a point, line and roughness. This can be calculated, for example, using a local histogram (a histogram covering the region of interest and the surrounding area) or a histogram of an image in which edges are extracted by means of a second-order Sobel filter or the like. Since the texture characteristic quantity normally contains a large amount of information, its number of dimensions may be appropriately decreased by a principal component analysis or similar technique in order to increase the processing speed. Other than these examples, any characteristic quantity commonly used in the image processing can be used.

[0042] The characteristic quantity data calculated for each divisional area in Step S2 are stored in a storage unit (not shown).

[0043] Using the input unit 12 (e.g. a mouse) connected to the controller 11, the user selects a partial and representative set of divisional areas (representative selected areas) within the observed image displayed on the screen of the display unit 13 (Step S3). FIG. 5 shows an example of the observed image on which the user has selected the representative selected areas by drawing the line 21. In response to such a drawing operation by the user, the controller 11 selects all the divisional areas including the line 21 as the representative selected areas (FIG. 6).

[0044] The controller 11 reads, from the storage unit, the values of the characteristic quantity of the representative selected areas specified by the user, and calculates their distribution (Step S4; FIGS. 7A and 7B). For ease of explanation, FIGS. 7A and 7B each show one-dimensional distribution of the representative selected areas with only the brightness value used as the characteristic quantity (brightness distribution).

[0045] In Step S5, a value range of the characteristic quantity for the divisional areas to be extracted as the measurement target region is determined for the distribution calculated in Step S4. In FIG. 7A, the mean value and standard deviation of the brightness distribution are calculated, and the range of 3 from the mean value is defined as the value range of the brightness to be extracted as the measurement target region. If a multi-peak distribution having two or more peaks as shown in FIG. 7B is obtained in Step S4, it is possible to divide the distribution into k sections (in the case of FIG. 7B, two sections) by k-means clustering or other techniques, and to calculate the value range of the brightness for each section by the previously described method. In Step S6, the characteristic quantity values of all the divisional areas are read from the storage unit, and each divisional area is checked for whether or not its characteristic quantity value is within the range calculated in Step S5. Then, every divisional area having a characteristic quantity value included in that range is extracted and designated as the analysis target region. After the analysis target region is thus designated, the controller 11 puts a specific color on the analysis target region in the observed image displayed on the screen of the display unit 13 (Step S7; FIG. 8). The user visually checks the image of FIG. 8 and completes the process if the analysis target region is set as intended. If the analysis target region is not set as intended, the user should appropriately increase or decrease the range of the representative selected areas. If the process in Step S7 results in the extraction of a plurality of mutually independent areas, all of those areas may be displayed on the screen. Alternatively, for example, a single area (i.e. an area which is not internally separated) including the representative selected areas specified by the user may be exclusively displayed.

[0046] Thus, the process related to the setting of the analysis target region is completed. Subsequently, for the analysis target region obtained by the previously described process, the controller 11 adjusts the opening size of the aperture element 5 and the position of the sample 3 placed on the movable stage 2, after which the infrared interference light is cast from the infrared interferometer to perform an analysis of the analysis target region.

[0047] In the previous embodiment, the value range calculated in Step S5 is defined as 3 from the mean value of the brightness distribution. Naturally, it is possible to allow users to appropriately set this range based on the distribution calculated in Step S4.

[0048] In the previous description, the user sets the representative selected areas within the region which is of interest to the user to extract the analysis target region. There is a different method for extracting the analysis target region. Specifically, this method is the opposite of the previously described method; it includes temporarily setting representative selected areas within an area other than the region of interest and extracting, as the analysis target region, a region exclusive of the representative selected areas. This method is hereinafter described with reference to FIGS. 9-11.

[0049] In the observed image of FIG. 9, the lump 23 is the region of interest to the user. On this observed image, the user temporarily sets the representative selected areas by drawing a line 22 within an area other than the region of interest (lump) 23 (Step S3). The consequently obtained characteristic quantity distribution (brightness distribution) is shown in FIG. 10 (Step S4). The brightness distribution of the representative selected areas in FIG. 10 does not include the brightness distribution within the region of interest 23. Therefore, in Step S5, the value range for the divisional areas to be extracted as the analysis target region is set in the opposite way, i.e. in such a manner as to exclude the brightness distribution of the representative selected areas (in the example of FIG. 10, the ranges outside 6 from the mean value). As a result, in Step S6, the divisional areas included in the aforementioned ranges exclusive of the representative selected areas are designated as the analysis target region. FIG. 11 shows analysis target regions designated in the observed image by the present method. In FIG. 11, not only the region of interest 23 but also many other areas are designated and colored as the analysis target regions. In such a case, the user selects the region of interest 23 by a mouse click or similar operation, whereupon the controller 11 automatically sets the position and size of the opening of the aperture element 5 to fit the opening into the clicked region. As shown in FIG. 10, if the line 22 is a closed curve and an extracted region exists inside that curve, it is possible to automatically designate the region inside the closed curve as the analysis target region, and automatically set the position and size of the opening of the aperture element 5 to fit the opening into that region.

[0050] Although only an infrared microscope is described in the previous embodiment, the present invention can be applied in various analyzers other than the infrared microscope, such as a microspectroscopy apparatus or imaging mass microscope.

REFERENCE SIGNS LIST

[0051] 1 . . . Infrared Interferometer [0052] 2 . . . Movable Stage [0053] 3 . . . Sample [0054] 4 . . . Half Mirror [0055] 5 . . . Aperture Element [0056] 6 . . . Reflection Mirror [0057] 7 . . . Infrared Detector [0058] 8 . . . Visible Light Source [0059] 9 . . . CCD Camera [0060] 10 . . . Data Processor

[0061] 100 . . . Fourier Transform Calculator [0062] 11 . . . Controller [0063] 12 . . . Input Unit [0064] 13 . . . Display Unit [0065] 21, 22 . . . Line [0066] 23 . . . Region of Interest (Lump)