SG193674A1

SG193674A1 - Apparatus and method for image acquisition and processing

Info

Publication number: SG193674A1
Application number: SG2012024493A
Authority: SG
Inventors: Yi Hui Tan
Original assignee: Yi Hui Tan
Priority date: 2012-04-04
Filing date: 2012-04-04
Publication date: 2013-10-30
Also published as: WO2013151509A1; SG11201406312XA

Abstract

APPARATUS AND METHOD FOR IMAGE ACQUISITION AND PROCESSING An apparatus for image acquisition comprising a tongue image acquisition assembly, the tongue image acquisition assembly comprising a light source and a reflector positioned to allow a tongue to be positioned therebetween; wherein the reflector of the tongue image acquisition assembly has a matt (non-shiny) surfaceFig. 1

Description

APPARATUS AND METHOD FOR IMAGE ACQUISITION AND

PROCESSING

FIELD OF THE INVENTION

The invention relates to an apparatus and method for image acquisition and processing. The invention is suitable (but not limited) for use in tongue image acquisition and processing in traditional Chinese medicine (TCM) applications and will be described in this context.

BACKGROUND ART

The following discussion of the background io the invention is intended fo facilitate an understanding of the present invention only. it should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred fo was published, known or part of the common general knowledge of the person skilled in the art in any jurisdiction as at the priority date of the invention.

In traditional Chinese medicine (TCM), the colour of a person's tongue is correlated {o the general health or sickness of the person. A TCM practitioner may observe the colour of a person's tongue at different regions of the tongue such as tip, central and back of the tongue in order fo provide a diagnosis of the person's health.

The colour of tongue may however be inconsistent when viewed with the naked eve, because the viewed colour is dependent on environmental factors such as ambient lighting, intensity of the ambient light, colour temperature, time of day, etc. As a slight variation between the shades of colour may result in very different diagnosis of a person's health, il is important to get the colour right in order to achieve an accurate diagnosis. in fight of the inconsistency and the effects of environmental factors, the TCM practitioner may be prone to wrong colour diagnosis or may require inordinate amount of time to ensure that the colour observed is as accuraie as possible.

Currently the process of a TCM practitioner observing the tongue colour and diagnosing is more of a qualitative rather than a quantitative process. As such, there is no uniform standard of diagnosis between different TCM practitioners.

Although there are known apparatus available {o assist the TCM practitioner in acquiring tongue images and processing these tongue images to obtain the colour data of the fongue for further diagnosis, these apparatus are generally located In hospitals and clinics. In addition, such apparatus do not have a dedicated colour acquisition system to ensure consistent lighting across different tongue images captured.

Further, known colour acquisition system and image processing system are 1¢ not able fo produce colour calibration with a satisfying degree of approximation io the true colour and a degree of consistency which does not vary across different machines.

Because human tongue is a non-rigid organ, the tongue has a high degree of variability in size, shape, colour, and texture. While automated fongue area detection is crucial and indispensable for computer-aided tongue diagnosis, but it is difficult to implement because of the physiological properties of the fongue.

The present invention seeks fo provide an apparatus and msthod that alleviates the above mentioned drawbacks at least in part.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the present invention, there is provided an apparatus for fongue image acquisition and processing comprising an apparatus for image acquisition comprising a tongue image acquisition assembly, the tongue image acquisition assembly comprising a light source and a reflector positioned to allow a tongue to be positioned therebetween; wherein the reflector of the tongue image acquisition assembly has a matt {non-shiny) surface.

Preferably, the reflector has an 18% grey surface.

Preferably, the image acquisition assembly comprises a cylinder having a mouth aperture shaped and sized to receive a subject's mouth.

Preferably, the reflector is the internal surface of the tongue image acquisition assembly.

In accordance with a second aspect of the present invention, there is a rubber/silicon lining for use with the mouth aperture according to claim 3. in accordance with a third aspect of the present invention, there is a method for tongue image processing comprising the following steps: a. receiving from an image capturing device RAW iongue colour images; b. performing white balancing on the received images; c. correcting the white balanced image; and d. classifying the corrected image into one of the TCM classified tongue colours

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described, by way of example only, with reference to the accompanying drawing, in which:

Fig. 1 is a perspective representation of an apparatus in accordance with an embodiment of the present invention.

Fig. 2a and 2b shows the perspective and side view of the image acquisition assembly respectively in accordance with an embodiment of the present invention.

Fig. 3 shows various rubber/silicon linings adapted for different sizes for use with the mouth aperture according with an embodiment of the invention

Fig. 4 shows the image acquisition assembly of Fig. 2 in the opened position exposing the interior.

Fig. 5 shows an alternative filter holder of the image acquisition assembly of

Fig. 4.

Fig. 6a and Fig. 6b shows the back view of the apparatus showing a camera and mobile phone as the image acquisition device.

Fig. 7 and 8 show the classification of colours based on inputs from TCM practitioners for each tongue image;

Fig. 8 shows an example of a captured tongue image in accordance with an embodiment of the invention; and

Fig. 10 shows another possible application of the invention based on the classification of colours of teeth from dental practitioners.

Other arrangements of the invention are possible and, consequently, the accompanying drawings are not fo be understood as superseding the generality of the preceding description of the invention.

PREFERRED EMBODIMENT OF THE INVENTION

In accordance with an embodiment of the present invention shown in Fig. 1 there is an apparatus 10 for image acquisition and processing comprising an image acquisition assembly 12. The apparatus may further include a chin rest assembly 14; and a base plate 18. The image acquisition assembly 12 may be mounted onto the base plate 16 using an assembly stand 18.

The apparatus 10 is suitable for, but not limited fo the acquisition of tongue image for traditional Chinese medicine (TCM) applications and will be described in the context of a tongue image acquisition device.

The tongue image acquisition assembly 12 comprises a front cover 22, a central enclosed area 24 and a back cover 28. Central enclosed area 24 comprises a slot 28 shaped and positioned on cone side of the central enclosed area 24 for holding a light source 30. The back cover 28 comprises a mount 31 for mounting an image acquisition device such as a digital camera or mobile phone enabled with an image acquisition device.

Front cover 22 may be releasably attached/detached to/from the central enclosed area 24 respeclively. Front cover 22 has a mouth aperture 32 shaped 0 receive the nose and mouth of a person. Mouth aperture 32 is shaped and sized such that when a person places his or her mouth in the central enclosed area 24, the mouth aperture 32 further contacts the cheeks of the person so as to prevent unnecessary movement when the person sticks out his/her tongue for image acquisition.

Front cover 22 further comprises a slot for the insertion of a colour chart 23.

Colour chart 23 is used for subsequent colour comparison, calibration and correction after longue images are acquired.

The mouth aperture 32 may be fitted with a rubber/silicon lining 33 as shown in Fig. 3. The rubbert/silicon lining 33 is disposable and is available in various different sizes to fit different user profile(s}). As rubber/silicon lining 33 is flexible and could adapt slightly fo the user's nose and mouth profile, rubber/silicon lining 33 further minimize the external lighting from entering the central enclosed area 24 when in use as it fits snugly with the user's nose and mouth. Each rubbert/silicon lining 33 is preferably a one-time usage item for sach individual for hygienic reasons.

The central enclosed area 24 is preferably a cylinder. Central enclosed area 24 comprises a filter/rest holder 34 for holding light filter 36 (see Figure 4 and 5). Light filter 36 may be in the form of a suitable paper medium.

Fig. 4 shows a filler holder 34 having gaps 34a therebetween, each gap covered by filter paper 36, thus allowing filtered light to pass through when the apparatus 10 is in operation.

Fig. 5 shows an alternative rest holder 34 which is a frame type rest holder 34.

The rest holder 34 depicted in Fig. 5 provides an continuous area for filter paper 36, which advantageously provide an unblocked region for light from the light source 30/bulb 38 to pass through without being blocked by any other medium except the light filler paper 36.

At least one bulb 38 is electrically connected to the light source 30. When in use, rest holder 34 is positioned at a distance from the at least one bulb 38.

An example of a suitable light source 30 would be one of high Color

Rendering Index (CRI) e.g. 80 or above and with Day Light Color

Temperature of at least 5500K (approximating sunlight).

The internal surface of the cylinder 24 is preferably matt so that it enhances the “davlight effect’ i.e. it increases the colour rendering index and day light colour temperature. The daylight effect may be enhanced via the curvature; the surface; and the colour properties of interface surface of the central enclosed area 24. As light from the light bulb 38 hits the internal surface of the central enclosed area 24, the reflected light is directed towards the tongue {when in proper use) and thereby further illuminates the fongue.

To achieve an optimal "daylight effect, the internal surface may be an 18%

Grey surface (Hue = 0, Saturation = 0, Luminance = 82).

The internal surface of the central enclosed area 24 thus acts as a ‘sun bounce’, ie. the curved intemal surface of the central enclosed area 24 functions as a reflecior. However, unlike most commonly known sun bounce techniques, where the light source (for example camera flash) is placed between a reflector and the subject, the subject (longue) is positioned in between the internal surface (reflector) and the light source. Such an arrangement avoids the possible "dark zone” casting onto the subject due to the physical existence of the light source.

An exhaust fan 40 may be positioned at the base of the central enclosed area 24. The exhaust fan 40 may be placed at a suitable position near io the front cover 22 where the aperture 32 is. One particular use of the exhaust fan 40 is to remove moisture from the central enclosed area 24. Moisture may enter the central enclosed area 24 for example when the subject breathes into the central enclosed area 24 and/or evaporation of moisture on the tongue when image acquisition is taking place, thereby creating an environment which may cause the image acquisition device (e.g. the camera lens) to be blurred.

Moisture may also be further introduced into the central enclosed area 24 when the aperture lining 33 is put in place.

The back cover 26 comprises a mount 31 for mounting the image acquisition device 42. The image acquisition device 42 may be either a digital camera or a mobile phone enabled with a camera or image capturing device, or any other suitable image acquisition device. It is fo be appreciated that the image acquisition device 42 is capable of capturing and saving images in RAW format. An example of a mobile phone which supports RAW format is the

Mystery HTC Windows Phona™.,

The tongue image acquisition assembly 12 may further include a mirror fixture 44. The mirror fixture 44 is intended for a user to adjust his or her own position in order fo capture proper images, especially where a qualified practitioner/technician is not around.

The tongue image acquisition assembly 12 is mounted on the assembly stand 18 which is subsequently mounted onto the base plate 16.

The chin rest assembly 14 is mountable at a position adjacent to one end of the base plate 18. Chin rest assembly 14 further comprises a forehead support as added support for the subject to restrict movement when image acquisition is taking place.

Tongue image acquisition assembly 12 is movable along a portion of a length of the base plate 16. This is enabled via a slot 46 made in the base plate 16.

The assembly stand 18 interfaces with the slot 46.

When in use the tongue image acquisition assembly 12 is movable towards or away from the chin rest assembly 14. A subject whose tongue image is to be captured places his or her chin on the chin rest assembly 14; the TCM practitioner or a qualified technologist then moves the tongue image acquisition assembly 12 towards or away from the chin rest assembly 14 in order for the mouth and nose of the subject to fit the aperture 32. Fine tuning of the chin rest assembly 14 may be made using an adjuster 48. The fine tuning ensures that the position of the chin of the subject is aligned with the mouth aperture 32 so that the subject is comfortable and proper image acquisition can take place. The TCM practitioner may switch on the apparatus 10 for the movement and fine-tuning of the fongue image acquisition assembly 12 and chin rest assembly 14 to ensure that adequale amount of light is projected onto the subject's tongue before acquiring any tongue images.

Once the apparatus 10 is properly adjusted and light bulb 38 is switched on, image acquisition/capturing can take place. For each subject, the image acquisition device 42 fakes at least one tongue image. Each tongue image taken preferably includes the colour chart 23 (see Fig. 9).

The acquired/captured RAW format images from the image capturing device 42 may be seni to a local processor 50 (not shown) for further image processing and colour correction. The image processing includes the following steps:- a. While-balancing on the local processor 50 (not on the image acquisition device's 42 own processor) b. Colour space configuration—preferably set to LAB colour space/colour chart 23; and assignment of adjustment values (Preferably, Pro RGB colour space and LAB environment is used) c. Colour comparison of the acquired/capiured RAW format image with the colour chart 23 d. determining the colour difference between the colour of the tongue image and the colour chart 23 &. obtaining a difference (delta E) value quantifying the colour difference value; and f. determining if the tongue image based on the delta E value should be accepted or rejected; and compensation of the colour difference based on the delta E value

Once the corrected image is obtained, the TCM practitioner who obtained the image will select a portion of the tongue image which is relevant for his diagnosis. The selected tongue image portion will be converted and classified into one of the seven basic tongue colours, and/or higher resolution if available, ready for analysis and diagnosis by a TCM practitioner. However, as the assessment of fongue colour and thus diagnosis may vary across different TCM practitioners, a database 50 is created to collate the diagnosis provided by different TCM practitioners. The database 50 maps the LAB or

RGB values of each colour to the TCM practitioners’ identification to the 7 primary tongue colours:-

Pale (HE); dim pink (38), pink (RZD); red (£1); scarlet (41%); dark red (BE41); and dark purple (45g)

As shown in Fig. 8, the 7 groupings are generally in the form of ellipsoidal shape, thus the 7 ellipsoidal shapes in the 3 dimensional space represent the 7 basic colour structure in TCM in accordance fo different TCM practitioner's input. it is to be appreciated that the 7 basic groupings may be further sub-divided into fourteen groups or fwenty-one groups. The fourteen groups may be achieved by differentiating each ellipsoid into Inner Core and Quter Core. The twenty-one groups may be achieved by differentiating each ellipsoid into Inner

Core, Middle Core, and Outer Core. Examples of the fourteen groups and twenty-one groups may be seen in Fig. 7 and Fig. 8. it should be appreciated by a person skilled in the art that the invention is not limited to the examples described. In particular, the following additions and/or modifications can be made without departing from the scope of the invention: + The aperture 32 and/or image acquisition system may be modified to allow insertion of any other body parts for example teeth. = An added illustration is shown in Fig. 10, wherein 4 ellipsoidal shapes, may be used to quantify the Whiteness of teeth after a visit to Dentist or cosmetic dentistry, (Pearly White / Pale While / Bright White / Ideal

White).

Claims

The Claims Defining the Invention are as Follows

1. An apparatus for image acquisition comprising a tongue image acquisition assembly, the tongue image acquisition assembly comprising a light source and a reflector positioned to allow a tongue {0 be positioned therebetween; wherein the reflector of the fongue image acquisition assembly has a matt {non-shiny} surface.

2. An apparatus according to claim 1, wherein the reflector has an 18% grey surface.

3. An apparatus according to claim 1, wherein the image acquisition assembly comprises a cylinder having a mouth aperture shaped and sized io receive a subject's mouth.

4. An apparatus according fo claim 1, wherein the reflector is the internal surface of the tongue image acquisition assembly.

5. A rubber/silicon lining for use with the mouth aperture according to claim 3.

6. A method for tongue image processing comprising the following steps:

a. receiving from an image capturing device RAW tongue colour images;

b. performing white balancing on the received image;

¢. correcting the white balanced image; and d. classifying the corrected image into one of the TCM classified tongue colours