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4.1 This practice is used to evaluate the ability of a radiographic interpreter to discriminate low contrast slit images in a radiographic interpretation environment. A radiographic viewer, as described in Specification E1390, and a viewing environment, as described in Guide E94, are strongly recommended. The minimum acceptable test score in any given application depends on the requirements of the application. Using parties should develop and maintain records of their test results to guide the establishment of acceptable test scores for their applications. (See Note 1.)NOTE 1: During round robin testing with experienced radiographic interpreters, 76 % of the interpreters achieved a score of 85 % or higher, and 95 % achieved a score of 80 % or higher. The average score was 90.7 %, and the standard deviation was 6.7 %. In a second study from 2017, with both certified radiographers and uncertified personnel, the average and standard deviation among certified radiographers was 90.4 ± 4.0 % and among uncertified personnel was 88.4 ± 4.9 %. It was found that on each test page there are 3 or 4 images where the average score for each was less than 80 % correct and the remainder of the images all individually scored greater than 80 % on average. A limited number of the general public was examined, and the average score among these was 75.0 ± 3.3 %.4.2 Administration of the Test 4.2.1 The test procedure described in this practice is intended to determine the ability of a radiographic interpreter to detect low contrast images in a low light level environment. Appropriate dark adaptation time should be permitted. A minimum of 1 min is recommended; however, longer dark adaptation times may be required by some users.4.2.2 The test shall be administered by or under the direction of a test administrator (see 3.2.4). The individual being tested shall not know the identification of the plate or orientation prior to the test.4.2.3 The interpretation of each of the 25 image areas on a plate is recorded on an answer sheet, Fig. 2, by drawing a line corresponding to the location and orientation of the slit image in that image area. Where no line image is detected, a circle should be drawn on the answer sheet in the area corresponding to the image area in which no slit image was detected. An example score sheet is given in Fig. 3, illustrating typical line locations and orientations and illustrating the method for marking answers. The markings shown in the sample score sheet are not taken from any of the actual test plates; however, they illustrate typical distributions of slit images. Fig. 2 of this practice may be photocopied to provide answer sheets, or the using organization may generate their own suitable answer sheet. In any case, the answer sheet must have provisions for recording both the location and orientation of the indication in each of the 25 image locations.FIG. 2 Visual Acuity Test Score SheetFIG. 3 Example of Completed Visual Acuity Test Score Sheet4.2.4 The order in which the indications are marked is not important. The reader may mark the indications in order, or may mark the easier images and return to the more difficult images.4.2.5 Once the score sheet is completed, the test administrator shall determine the identity and orientation of the plate that was read and score the answers using the appropriate answer key.1.1 This practice details the procedure for determining the low-contrast visual acuity of a radiographic interpreter by evaluating the ability of the individual to detect linear images of varying radiographic noise, contrast, and sharpness. No statement is made regarding the applicability of these images to evaluate the competence of a radiographic interpreter. There is no correlation between these images of slit phantoms and the ability to detect cracks or other linear features in an actual radiographic examination. The test procedure follows from work performed by the National Institute of Standards and Technology presented in NBS Technical Note 1143, issued June 1981.1.2 The visual acuity test set consists of five individual plates, each containing a series of radiographic images of 0.5 in. (12.7 mm) long slits in thin metal shims. The original radiographs used to prepare the illustrations were generated using various absorbers, geometric parameters (unsharpness, slit widths), and source parameters (kV, mA, time) to produce images of varying noise, contrast, and sharpness. Each radiographic image has a background density of 1.8 ± 0.15. The images are viewed in a radiographic interpretation environment as used for the evaluation of production radiographic films, for example, illuminators and background lighting as described in Guide E94 and Specification E1390, and without optical magnification.1.3 Each visual acuity test plate consists of 25 individual image areas. The images are arranged in 5 rows and 5 columns as shown in Fig. 1. Each image area is 2 in. x 2 in. (51 mm x 51 mm). All identification is on the back side of the plate. Each plate can be viewed from any of the four orientations (that is, it can be viewed with any of the four edges “up” on the illuminator). Since there are five different plates in the set, this makes for a total of 20 different patterns that can be viewed. The identification of which of the five plates and which of the four orientations were viewed in any given test can be determined from the designation on the back side.FIG. 1 Layout of Visual Acuity Test Plate1.4 Within the image areas, the slit image may appear in any of five locations, that is, in any of the four corners of the image area, or near the center. No more than one slit image will appear in any one image area. The slit image may be horizontal, vertical, slant left, or slant right. Several of the plates include one or more image areas in which there is no slit image.1.5 Use of this standard requires procurement of the adjunct test plates.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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4.1 Although color measuring instruments are widely used, color matches are usually checked visually. The standardization of visual examination has greatly improved the uniformity of products and the accuracy of color matches.4.2 The use of this practice is essential for critical color matching but is also recommended for any color appraisal, such as the choice or approval of a color. This practice is widely used in industry to choose colors, exhibit colors reproducibility, inspect incoming materials, monitor color producing processes, and inspect finished goods. Visual appraisal is particularly important when the product inspected is not of the same material as the color standard to which it is compared.4.2.1 Observers—This practice is based on the fundamental assumption that the observer has superior color vision and is trained and experienced in observing and classifying color differences. The significance of the results depends on that being so. The selection, evaluation, and training of observers are treated in Guide E1499.4.2.2 Illumination—Simulated average daylight, D65, is recommended by the International Commission on Illumination (CIE). D50 is recommended for applications involving color photography or color printing as specified in ISO 3364-2009.1.1 This practice specifies the equipment and procedures for visual appraisal of the colors and color differences of opaque materials that are diffusely illuminated. These specifications are of critical importance in color matching. This practice requires judgments by observers with a minimum of normal color vision and preferably superior as rated with the FM-100 Hue Test as specified in Guide E1499.1.2 Critical visual appraisal of colors and color differences of materials such as metallic and pearlescent paints requires illumination that is nearly a geometric simulation of direct sunlight, because such directional illumination permits observation of the sparkle (glitter) and goniochromatism that characterize such materials. Such viewing conditions are beyond the scope of this practice.1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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ISO/IEC TR 14496-9:2009 specifies descriptions of the main video coding tools in hardware description language (HDL) form. Such alternative descriptions to the ones that are reported in ISO/IEC 14496-2, ISO/IEC 14496-5 and ISO/IEC TR 14496-7 correspond to the need of providing the public with conformant standard descriptions that are closer to the starting point of the development of codec implementations than textual descriptions or pure software descriptions. ISO/IEC TR 14496-9:2009 contains conformant descriptions of video tools that have been validated within the recommendation ISO/IEC TR 14496-7.

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