Studies On Tongue Photography Methods And Application In Characterization Reserch Of Tongue Diagnosis

As an important part of study on characterization of tongue diagnostic, Tongue image shooting(TIS) plays fundamental role in it. Except on factors, such as the way of putting out tongue, food, season, exercise, the quality of tongue image could be also effected by digital camera(DC), illuminance. This study focuses on analyzing the factors by Application Optics, Chromatics, Photography, computer technology, and color management, expecting that the effect of these factors on quality of TIS could be minimized or even eliminated. This article is divided into 4 partsPart1 Document ResearchDeficiency of TIS in studies on on characterization of tongue diagnostic is presented following1. More attention shoud be paid on the effects of age, food, season, exercise, habit on TIS.2. The TIS system reached high standard on equality of color temperature (Tc), Luminosity, the stability of Tc and Luminosity, most of them are large and inconvenient to use.3. Deficiency of the study on DC. Few researcher has clear concept on what kinds of DC and lens are appropriate for TIS.4. Application of color management is insufficient. furthermore, different researchers followed different processes of management. The software and hardware in use are different too. Part2 Preparation of TISTo minimize the factors'effect on TIS, we summarize the achievement of former research, combined with our own experience, conclude that several principles should be followed.1.The factors like age, food, season, exercise, habit should be included in the description of tongue image, if their effects on TIS are visible.2. The patient to be photographed should avoid eating in 2 hours and drinking in half an hour.3. The patients should avoid exercise before TIS4. During TIS, photographer guide patients to put out tongue. Simple tongue exercise is available when patients are difficult in putting out tongue. TIS should be finished in 1 to 2 minutes.Part3 Illuminance equipments and Color Management1. IlluminanceTo minimize the factor's effect on TIS, we applied knowledge of Application Optics, concluded Specification of TIS illuminance:(1) Continuous spectrum. (2)Tc 6500K. (3) Ra>90. (4) Luminosity:2000Lx±500Lx, the equality of Luminosity:≥75%. (5)Disposal of illuminance:20cm-100cm away from tongue, symmetrical, angle of incidence is 45°～60°.Specification of TIS surroundings.The Luminosity of surrounding is less than 32Lx, the color of surrounding objects is neutral gray, the reflective index(RI) is less than 60%. we think clinic and ward measure up the Specification requested.2. Selection and Application of DC and LensSelection and application of lens:(1)Focus in length of lens 50mm≤f≤105mm. (2)prime lens,good at macro photography. (3)to minimize Lens Aberrations, increase the depth of field, we recommend using small aperture about f/8～f/11. widening the distance between DC and tongue.Selection and application of DC:(1)Chose Digital single-lens reflex camera (DSLR) with CCD sensor. (2)Color mode, modeⅡ(adobe RGB). (3)ISO.100, less than 400 while surrounding is dark. (4)White balance. Shoot gray card before TIS, measuring Tc using DC. (5)Focus. AF-S. (6)Hotometry and exposure. To increase the precision of Photometry, we place a 18% neural gray card or 3-class gray card, as close as possible to tongue, parallel with CCD, point Photometry on card, then compose picture and shoot. The histogram display on DC LCD is useful in evaluating exposure. (7)Shutter. Electronic shutter is suggested in TIS. We suggest use of tripod and Ascending viewfinder to prevent DC from vibrating, using "safe Shutter time", which is the length of lens in millimeter. shutter release and telecontrol shutter release are also useful. (8)Picture format. Use lossless compression algorithms to compress image, we suggest RAW format when shoot and save picture, and tiff format when print and edit picture, and JPEG format when the picture is only used on internet.3. Color ManagementIn this part, we discusse on basic theory of chromatics, the origin and development of color management, the process of the color management of DC and displayer.4. Description of Tongue ImageWe think the Description of tongue image should contain:(1)Day and place of photography. (2)DC Information:model, setup of DC and lens. (3)General information of patients:age, gender, name, food, habit, exercise, menstrual cycle. (4)Disease information:the name of disease in modern medicine, the name of disease and differentiation in TCM. (5)Description of tongue:tongue color, shape, movement, color of coating on the tongue, texture of tongue.Part4 experiment experiment I Under of the ring flash and natural light shooting tongue color cards and color correction and calibration image EvaluationObjective:To better reduce chromatic aberration of tongue images taken under natural light and cyclic flash, we compared two different color correction methods, hoping to provide methodological basis in TIS for further characterization of tongue diagnostic researches.Method:we calibrated x-Rite ColorCheckerTM passport color card images and tongue images taken under natural light and cyclic flash respectively applying two different color correction methods, then calculate chromatic aberration between color card and original data, and compare color visually between tongue images chromatically corrected by two different color correction methods and original tongue.Results:chromatic aberration of color card images uncorrected was larger than that of corrected under two different chromatic correction methods, indicating that chromatic correction was necessary in TIS.△E00,△L,△C was significantly lower than that corrected by gray card white balance method, showing that the former can significantly correct chromatic aberration and aberration of brightness and color saturation. The rate of color corrected by ICC-based color correction method same with original tongue color was largest. Therefore, we suggest ICC-based chromatic correction method in TIS.TestⅡpreliminary research on chromatic characteristics of blood stasis tongues and sublingual veinsObjective:In CIELAB color space, we researched on chromatic characteristics of blood stasis tongues and sublingual veins, hoping to find new objective indicators to diagnose blood stasis tongue and syndrome of blood stasis.Methods:we shot tongues of health, and tongues of patients of blood stasis and patients of non-blood stasis, L*a*b* values were extracted from the images of tongues and the sublingual veins, and then compared them statistically.Results:L* values of blood stasis tongues and sublingual veins were significantly lower than that of non-blood stasis and sublingual veins and tongues of the health, a* values were higher, indicating that L* a* values of tongues and sublingual veins can be objective indicators to diagnose blood stasis tongue and syndrome of blood stasis.Our creationFirst, Using Application Optics, chromatics, photography Techniques, computer technology, and color management, We studied on the effects of factors that would effect the quality of TIS, by cross-level, cross-subject and systematically, Providing ways to minimize or even eliminate them, and the ways have high value in clinical application of TIS.Second, applying the cyclic flash as a secondary light source, we used ICC file color correction method, and achieved satisfactory results, providing TIS another convenient, high-quality photographic method, so as to laid a solid foundation for further characterization tongue diagnostic researches.Third, for the first time, we compared the tongue color and sublingual veins color of blood stasis tongues and non-blood stasis tongues in the CIELAB color space, providing new objective indicators to diagnose blood stasis tongue and syndrome of blood stasis.