1、 AIIM MS50 94 m 1012348 0500579 TOb = ANSVAIIM MS50-1994 Standard Association for Information and Image Management 1100 Wayne Avenue, Suite 1100 Silver Spring, MD 2091 0-5603 Telephone 301/587-8202 Approved As Julv 11, 1994 AIIM US50 4 m 1012348 0500580 728 m AIIM Catalog No. MS50 O 1994 by the Asso
2、ciation for Information and Image Management 1100 Wayne Avenue, Suite 1100 Silver Spring, MD 20910-5603 USA Telephone: 30 1/587-8202 Fax: 301/587-2711 Printed in the United States of America ISBN:0-89258-285-5 AIIM MS50 94 M LOI12348 0500583 664 ANWAIIM MS50-1994 Standard for Information and Image M
3、anagement - Standard Recommended Practice - Monitoring Image Quality of Aperture Card Film Image Scanners Association for Information and Image Management Abstract This standard recommended practice specifies procedures for quality control of images produced when aperture cards are scanned. AIIM MS5
4、0 94 m 3032348 0500582 5TO m Contents Foreword i Scope and purpose . 1 Normative references 1 Definitions . 1 Principles of image quality control . 2 Procedures for test run . 4 Target 1 : Alignment target . 5 Target 2: Resolution target . 8 Target 3: Line target . 8 Frequency of testing 4 10 11 Tar
5、get 5: Typical engineering drawing . 9 Annexes A B (Informative) Target manufacturers Target 4: Focus target . 8 (Informative) Scanner test results log . 14 details . 15 B-1 Drawing: Aperture card 15 B-2 Drawing: Frame size and image alignment target (A-size) landscape . 16 B-3 Drawing: Frame size a
6、nd image alignment target (A-size) portrait . 17 B-4 Drawing: Frame size and image alignment target detail . 18 B-5 Drawing: Pestrecov star pattern and wedges . 19 B-6 Drawing: Pestrecov star pattern and wedges detail . 20 B-7 Drawing: Pestrecov star pattern and wedges details 2 and 3 21 B-9 Drawing
7、: Line width test detail 23 B-11 Drawing: Focus check target detail 25 C- 1 Drawing: Threshold target specification 27 B-8 Drawing Line width test (A-size) . 22 B-10 Drawing: Focus check target 24 (Informative) Threshold target 26 C Figures 1 2 3 4 5 6 Test run log . 3 Test target 1: Frame size and
8、image alignment target 6 Test Target No. 2: Pestrecov star pattern and wedges 10 Test Target No. 3: Line widths . 11 Test Target No. 4: Focus check . 12 Test Target No. 5: Typical engineering drawing . 13 Foreword (This foreword is not part of American National Standard for Information and Image Man
9、- agement, ANSUAIIM MS50-1994 - Standard Rec- ommended Practice for Monitoring Image Quality of Aperture Card Film Image Scanners.) This standard recommended practice addresses proce- dures for establishing the quality control of electronic images that are produced when aperture cards are scanned. I
10、t contains three informative annexes (A, B, and C), which are not to be considered part of this standard. Annex A (Scanner test results log) is a log sheet to be used to document various aspects of the quality control program. Annex B (Target manufac- turers details) contains eleven drawings (B- 1 t
11、hrough B-11) of the aperture card, frame size, and image alignment (A-size, both landscape and portrait), and other aspects of the aperture card test images. This annex provides additional information about Test Tar- gets Numbers 1, 2, 3, 4, and 5. Annex C (Threshold target) contains a description o
12、f a target that can be used to check scanner thresholding. The targets pro- vided in these annexes are for informational purposes only. These targets are available through commercial sources. 1 This standard recommended practice is only directed toward successful calibration of the scanner. The ulti
13、- mate users image requirements are dependent upon the scanner and other system components, such as printers and monitors. The systems operator must establish and maintain similar procedures for each of the system components that affect the output image. Every scanner, including replacement scanners
14、, must be calibrated. Some scanners have automatic image enhancement features; therefore it may be necessary to establish quality references to represent image enhanced output. Test Target Numbers 1, 2, 3, 4, and 5, which are referred to in this standard, are aperture cards. The thresholding target,
15、 also an aperture card, is described in Annex C, an informative annex, which is not a part of this standard. Members of the AIIM C13 Elec- tronic Imaging Standards Committee and the AIIM C 13.1 Electronic ImaginglAperture Card Scanning Committee acknowledge the efforts of Applied Image, Inc. of Roch
16、ester, New York, for the technical development of the targets. Following are descrip- tions of the targets. Test Target No. 1: Frame size and image alignment target Seven aperture cards - A size and B size: 16X reduction ratio (four aperture cards, both land- scape and portrait) - C size: 16X reduct
17、ion ratio (one aperture card, landscape) 1.Obtaining the test targets: Contact the Associa- tion for Information and Image Management (AIIM), Publications Sales, 1100 Wayne Avenue, Suite 1100, Silver Spring, Maryland 20910; (301) 587-8202; fax (301) 587-2711. i AIIM MS50 94 = LO12348 0500583 437 - D
18、 size: 24X reduction ratio (one - E size: 30X reduction ratio (one aperture card, landscape) aperture card, landscape) Test Target No. 2: Pestrecov star pattern and wedges One aperture card - Pestrecov star pattern and wedges Test Target No. 3: Line widths Five aperture cards -A, B, C, D, and E size
19、 Test Target No. 4: Focus check One aperture card Test Target No. 5: Typical engineering drawing One aperture card Threshold Target One aperture card Suggestions for improvement to this standard are wel- come. They should be sent to the Chair, AIIM Stan- dards Board, Association for Information and
20、Image Management, 1100 Wayne Avenue, Silver Spring, At the time it approved this standard recommended practice, the MIM Standards Board had the following members: Name of Representative Organization Represented MD 20910-5603. Marilyn E. Courtot, Avi Bender Thomas C. Bagg Chair Jewel M. Drass John C.
21、 Gale Bmce A. Holroyd Charles A. Plesums George Thoma Stephen Urban Eileen Usovicz Herbert J. White Association for Information and Image Management CONTEL Federal Systems National Institute of Standards and Technology Bell (2) Distortion of an image on a raster scan display caused when the detail o
22、f an image exceeds the resolution of the cathode ray tube (CRT); (3) Image defects generally caused by elements of a scanned image being smaller or not registered with the picture element. 3.2 Halftone: Technique of reproducing continuous- tone illustrations by photographing the image through an etc
23、hed screen. NOTE: The finer the screen (mea- sured in lines per inch or millimeter), the higher the quality of the resulting negative. 3.3 Image scanner: For the purpose of this docu- ment, a scanner or image scanner is a device that elec- tronically captures data from an aperture card in a ras- ter
24、 pattern and creates a digital file of the monochrome image of the document. Also see scan- ner, 3.9. 3.4 Moire: An image defect caused by interference of one pattern with another, which shows as a beat frequency between the two patterns. 3.5 Point: Also printers point. Measure of type size in graph
25、ic arts type. Nominally 1/72 inches, precisely 0.013837 inches (0.3514598 mm). 3.6 Post-test: A verification test performed after the original documents are scanned. 3.7 Pre-test: A calibration or verification test per- formed before the original documents are scanned. 3.8 Rectangularity: A measure
26、of the equality of the lengths of opposite sides of a rectangle and the correctness of the angles. With perfect rectangularity, the opposite sides will be of exactly equal length and the angles will be exactly 90 degrees. 3.9 Scanner: A device that converts a document into binary (digital) code by d
27、etecting and measuring the intensity of light reflected from paper or transmitted through microfilm. 3.10 Serif: In a typeface, the short decorative cross lines at the ends of the strokes in some characters. A typeface with no serifs on any characters is referred to as a sans-serif typeface. 3.11 St
28、air-stepping: See aliasing, 3.1. 3.12 Target:Any document or chart containing iden- tification information, coding, or test charts. 3.13 Test chart: An image, comprised of different (or a number of the same) test targets, designed for test and evaluation of imaging systems. 3.14 Test element: An ima
29、ge designed for test and evaluation of imaging systems, e.g., a specific line of type that is set in a particular point size, a specific col- lection of horizontal and vertical lines and spaces, a line that represents a specific frequency, i.e., 50 cycle/ mm and 152.4 mm (6.0 inch) length. 3.15 Test
30、 pattern: An image that is comprised of a collection of test elements, (e.g., resolution test ele- ments, frequency test elements) and that is designed for test and evaluation of imaging systems. 3.16 Test target: An image, comprised of test pat- terns and/or test elements, designed for test and eva
31、lu- ation of imaging systems. 4 Principles of image quality control 4.1 General Image quality control is the term given to the proce- dures and techniques that are used to maintain consis- tency of output. Properly used, these procedures answer the question, “Is what I am producing today as good as
32、the best I can produce? The answer to this question is used to determine if production can con- tinue or if a maintenance technician must be called. A second question may also be answered - “Is what I am producing today as good as what I produced yes- terday? The answer can be used to show the varia
33、- tions of a piece of equipment while it is still within allowable performance limits. 4.2 In the typical digital image management system, aper- ture cards are scanned and indexing information is entered. In some systems, the scanned image of the aperture card may never be examined until it is neede
34、d. Strict image quality control is required to assure that the images stored are of acceptable quality and are able to be located by way of the index. If a scanner is not operating properly, a large number of useless images may be stored on the system. When the problem is discovered and corrected, t
35、he original documents will have to be scanned again. Procedures should be established so that any problems are discov- ered while the original documents are still available. The image quality monitoring procedures described in this document allow the user to make sure that the system is performing t
36、oday as well as it was when originally adjusted by the manufacturer and as approved by the user. Used on a regular basis, these procedures can assure users that the scanner will pro- duce digital images of sufficient quality for their intended use. Defining the need for image quality control 4.3 Est
37、ablishing a qualiy reference It is extremely important to establish the definition of “good output” from a digital image management sys- tem. It is the nature of these systems that some images 2 (black-and-white text) will be more faiffilly recorded than others (haiftones, color, etc.). Comparing a
38、current target image against a known reference allows a non- technical user to easily make judgments about system quality. To establish a quaiity reference, the entire system must be working. The scanner should be adjusted to provide the best possible results for the type of material to be scanned.
39、All of the targets, the five described in this practice (Figures 1 through 5) and all targets made by the user, should be scanned. The targets should be out- put to hard copy and carefully examined. If the quality of the targets is sufficient for normal use, the hard cop- ies should be carefully pre
40、served and the digital images may be stored on electronic media. Au scanner adjust- ment settings should be noted on the hard copy. The result of this process becomes the quality reference. If the normal use of the scanner is to scan all aperture cards in the order in which they come, without regard
41、 for content, then the scanner setup used for the quality reference should reflect the best compromise of settings for the different types of originals that WU be encoun- tered. Some users change the scanner settings for each aper- ture card according to the content of the aperture card. Other users
42、 sort aperture cards according to scanner parameters, and change the scanner settings before each batch of aperture cards of the same type or have separate scanners for different types of aperture cards. In any of these cases, it is desirable to create a separate quality reference sec for each type
43、of aperture card that will be treated separately. The user should be aware that any maintenance done to a scanner may affect the actual results of the user con- trollable settings. For this reason, any time the scanner is recalibrated by a technician, a test run of all targets should be made. Once a
44、 match for the original quality of the targets has been achieved, the new proper set- tings should be recorded. If the original quality of tar- gets cannot be achieved, then either the scanner still has a problem, or the calibration was not performed prop- erly. In either case, additional corrective
45、 maintenance is probably necessary. (A good general rule is to run the test targets before signing off on maintenance. It is easier to ask the technician to re-adjust the scanner immediately than it is to call the technician back when the next test is done before a scan batch.) 4.4 Pre- and pt-tasun
46、g While it is desirable to make sure that every film image is scanned correctly, it is clearly not practical to do a test run before each aperture card to be scanned. When batches of similar aperture cards are to be scanned, a good compromise is to do a test run before the batch, check that the scan
47、ner is properly set up and working, scan the batch, then do a test run after the batch to make sure the results are still acceptable. If the final pre-scan test run and the post-scan test rn are the same, the scanner can be assumed to have been working properly during the whole scanning session (as
48、long the scan- ner adjustments were not touched during the scanning session). If the post-scan test image is not acceptable, the aperture card images in the scan batch should be examined to determine which, if any, must be scanned again. Where the scanner is adjusted separately for each aper- ture c
49、ard, the pre- and post-testing approach outlined will not work. One approach for this situation is to determine, by way of pre-testing, a small number of allowable settings that the scanner operator may use during the entire scanning session (one setting per aper- ture card type). This pre-testing will be done primarily with a user-created target. Following the scanning ses- sion, the operator should post-test with the same target, using the settings established in the pre-test run. Com- paring the respective pre-and post-test runs will deter- mine if the scanner h
