AVIXA V201.01:201X Image System Contrast Ratio …...154 to measure luminance reflected from, or transmitted through, the projection screen or as measured from the face of 155 the

AVIXA V102.01:201X, DS1

© 2019 by AVIXATM | Page i

AVIXA V201.01:201X 1

Image System Contrast Ratio 2

DS1 3

[publication date] 4 5 NOTICE: This document is a draft prepared by AVIXA, Inc. for the use of the Image System Contrast Ratio Task Group 6 only. This document is not to be copied, disseminated, shown to, distributed to, or shared with any other person or 7 entity outside of the use of this task group. The draft is dynamic in nature and is subject to change. 8 9

Abstract 10

This Standard defines image system contrast, expressed as a ratio, and its measurement. It applies to permanently 11 installed and temporary display systems and all displayed images regardless of AV technology (e.g., direct view 12 display, rear projection, front projection). The AV image system includes the display, source equipment, signal path 13 and distribution, and the room environment. System contrast ratio measurements are taken in the system’s typical 14 use case (e.g., classroom with ambient light and a video distribution system throughout the school). Four contrast 15 ratios are defined and are based on content viewing requirements. Practical metrics to measure and validate the 16 required contrast ratios are provided. 17 18

Keywords 19

Analytical decision making; audiovisual; (AV); audiovisual standard; AV; AV system performance; AVIXA; basic 20 decision making; contrast; contrast ratio; detail; digital signage; direct view display; front projection; full motion 21 video; image contrast; image quality; InfoComm; information; informational display; inspection; passive viewing; 22 presentation; projected image; projector; projection; projection screen; rear projection; screen; system contrast 23 ratio; videoconferencing. 24 25

Disclaimer 26

The application of this Standard is strictly voluntary. AVIXATM recommends its use but does not assume responsibility 27 for misinterpretation or misapplication. AVIXA does not assume liability for disputes resulting from non‐28 conformance to this Standard. Conformance does not imply certification of a system. 29 30

Copyright 31

© 201X by AVIXATM. This Standard may not be reproduced in whole or in part in any form for sale, promotion, or any 32 commercial purpose, or any purpose not falling within the provisions of the U.S. Copyright Act of 1976, without prior 33 written permission of the publisher. For permission, address a request to the Director of Standards, AVIXA. 34

35

AVIXA V102.01:201X, DS1

© 2019 by AVIXATM | Page ii

Foreword 36

37

When ANSI/INFOCOMM 3M‐2011, Projected Image System Contrast Ratio (PISCR) was published, it applied to 38 projection only. As direct view displays became more prevalent, a task group was convened to assess the 39 technological characteristics of direct view displays to determine whether the differences in technologies would 40 affect the manner in which image system contrast was assessed, thus requiring an additional standard to address 41 display technologies other than projection. 42 43 Through the revision process and after numerous tests, the direct view display image system contrast ratio task 44 group concluded that the measurement process used in the original PISCR standard was equally appropriate for 45 direct view displays. However, the addition of sequential testing was deemed necessary to accurately characterize 46 the image system’s contrast for any technology. 47 48 Both the original standard and this revision determine the required contrast ratios for four viewing categories based 49 on the user’s need to assimilate and retain detail. The categories and their descriptions have stayed the same. 50 51 Based on additional testing and user feedback, two additional test patterns are required to provide accurate 52 sequential measurements. The test patterns are widely used and readily available in the marketplace. The addition 53 of these requirements adds only two measurements to each viewing location. 54 55 Contrast remains a critical element for a satisfactory user experience when viewing a displayed image. Conformance 56 to this standard will provide a level of confidence that the assimilation and retention of necessary detail will be more 57 readily achieved by the viewer. 58 59 The five measurement locations originally defined in the standard have also remained. 60 61 Conformance to the revised Standard is now strictly pass/fail, with no partial conformance allowance. Identification 62 of potential causes for non‐conformance must still be proposed in the conformance report. 63

64

65

66

67

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AVIXA Standards Program Developers 68

At the time of this Standard’s development, contributors’ names and affiliations are as shown: 69 70 IMAGE SYSTEM CONTRAST RATIO PERFORMANCE STANDARD TASK GROUP 71 72 To be added 73 74 AVIXA STANDARDS STEERING COMMITTEE 75 76 To be added 77 78 79 AVIXA STANDARDS STAFF 80 81 To be added 82 83

84

AVIXA V102.01:201X, DS1

© 2019 by AVIXATM | Page iv

Table of Contents 85

86 Table of Figures ................................................................................................................................... iv 87

1. Scope, Purpose, and Application .............................................................................................. 1 88

1.1. Scope .....................................................................................................................................1 89 1.2. Purpose ..................................................................................................................................1 90 1.3. Application ............................................................................................................................1 91 1.4. Exclusions ..............................................................................................................................2 92

2. Referenced Publications ........................................................................................................... 4 93

2.1. Normative References ...........................................................................................................4 94

3. Definitions ................................................................................................................................. 5 95

3.1. Definitions .............................................................................................................................5 96

4. Requirements ........................................................................................................................... 7 97

4.1. Viewing Requirement Categories and Minimum Contrast Ratios .........................................7 98 4.2. Viewing Area Plan ..................................................................................................................7 99 4.3. Measurement Locations ........................................................................................................7 100 4.4. Image System Measurement Procedure ...............................................................................8 101 4.5. Measurement Procedure ......................................................................................................9 102

5. Verification ............................................................................................................................. 12 103

Annex A — Examples of Viewing Area Plans .................................................................................... 14 104

6. Annex B — Sample Forms (Informative Annex)...................................................................... 16 105

7. Annex C — Viewing Requirement Categories ‐ Extended Information (Informative) ............ 19 106

8. Annex D — Rationale for Sequential Test PATTERN (Informative) ......................................... 23 107

9. Annex E — Bibliography (Informative) ................................................................................... 24 108

109 110

Table of Figures 111

Figure 1: Minimum contrast ratios for viewing categories ............................................................................................ 7 112 Figure 2: Viewing locations ............................................................................................................................................ 8 113 Figure 3: White window test pattern .......................................................................................................................... 10 114 Figure 4: Full‐screen black test pattern ....................................................................................................................... 11 115 Figure 5: Viewing area plan – classroom ................................................................................................................... 14 116 Figure 6: Viewing area plan – boardroom ................................................................................................................... 14 117 Figure 7: Viewing area plan ‐ huddle/screening room ................................................... Error! Bookmark not defined. 118 119 120

ANSI/AVIXA V102.01:201X, DS1

© 2019 by AVIXATM | Page 1

1. SCOPE, PURPOSE, AND APPLICATION 121

1.1. Scope 122

This Standard addresses the image contrast ratio of display systems typically used in presentation environments. 123 Although these methodologies and procedures can be applied to many types of display systems and applications other 124 than for presentation, this Standard pertains only to AV presentation systems including both permanently installed and 125 temporary systems. 126 127 The Standard defines the “image system” as the technology used to display the image and the ambient environment in 128 which the image is being displayed. Measurement results are reported as a ratio. 129 130 This Standard is limited to image contrast ratio measurements and does not include testing and measurement of related 131 factors such as display luminance, resolution, image size, or other factors relating to the overall performance of the 132 displayed image. The contrast of an image is measured using a 16‐zone black‐and‐white checkerboard test pattern, a 133 white window pattern, and a full‐screen black test pattern. All patterns used are readily available in the marketplace. 134

1.2. Purpose 135

The purpose of this Standard is to define acceptable minimum contrast ratios for AV presentation systems relative to 136 their stated purpose or application. By defining the image system contrast ratios and providing suitable measurement 137 and reporting methodologies, metrics for system specification can be determined and verification can be assessed. 138 139 For the purposes of this Standard, “image system” includes the display, sources, signal path and distribution, and the 140 environment. The contrast ratios defined in this document comprise a combined output of an “image system.” Contrast 141 is qualified as “image system contrast (expressed as a) ratio” (ISCR), because the individual performance of the projector 142 and screen or the direct view display are only contributory factors to the ultimately delivered contrast ratio of the 143 installed system. It is also termed as “system” contrast ratio because the maximum contrast ratio a projector and screen 144 or a direct view display can deliver to the viewer is unavoidably affected by ambient light, which should therefore be 145 considered when trying to accurately assess the true viewing environment 146 147

In this context, contrast is defined as the absolute difference in luminance between the peak white and black levels, 148 where white and black luminance are displayed and measured both simultaneously and sequentially using the 149 prescribed test patterns. The definition for simultaneous white and black luminance and its measurement is commonly 150 referred to as “ANSI contrast ratio.”1 This Standard uses a 16‐zone black‐and‐white checkerboard test pattern to 151 measure luminance reflected from, or transmitted through, the projection screen or as measured from the face of the 152 direct view display. In addition, the Standard uses an 18% white window test pattern and a full‐screen black test pattern 153 to measure luminance reflected from, or transmitted through, the projection screen or as measured from the face of 154 the direct view display. 155

1.3. Application 156

This Standard is designed to facilitate informed decision‐making for projector, screen, and direct view display selection 157 relative to location and stated purpose. Requirements of this Standard apply to: 158

a) Planning and designing image system installations; 159

b) Setting minimum and optimum contrast ratios relative to stated purposes; 160

c) Testing and signing off on completed image system installations; and 161

1 The original ANSI standards, retired in July of 2003, ANSI/NAPM IT7.228‐1997 Electronic Projection – Fixed Resolution Projectors

and ANSI/PIMA IT7.227‐1998 Electronic Projection – Variable Resolution Projectors, measured illuminance (i.e., measurement of direct light from the projector).



d) Determining remedial solutions for a system not conforming with this Standard or inadequate for the stated 162 purpose. 163

Four viewing categories define the required contrast ratios relative to stated purpose or application. A viewer is defined 164 as a person with normal/corrected vision, or normal visual acuity2. Visual acuity is the capacity of the eye to see fine 165 detail measured by determining the finest detail that can be detected. 166

167 The four viewing requirement categories are: 168

169

1. Passive Viewing 170

The viewer can recognize the displayed images and separate the text or main image from the background under 171 typical lighting for the viewing environment. The content does not require assimilation and retention of detail, but 172 the general intent is understood. The viewer is passively engaged with the content (e.g., non‐critical or informal 173 viewing of video and data). 174

2. Basic Decision Making 175

The viewer can make basic decisions from the displayed image. The decisions are not dependent on critical details 176 within the image or text, but there is assimilation and retention of information. The viewer is actively engaged with 177 the content (e.g., information displays, presentations containing detailed images, classrooms, boardrooms, multi‐178 purpose rooms, product illustrations). 179

3. Analytical Decision Making 180

The viewer can make decisions by analyzing critical details within the displayed image. The viewer is analytical and 181 fully engaged with these details of the content (e.g., architectural/engineering drawings, image examination, 182 forensic evidence, photographic image inspection). 183

4. Full Motion Video 184

The viewer can discern key elements present in the full motion video, including detail provided by the 185 cinematographer or videographer necessary to support the story line and intent (e.g., business screening room, 186 business presentation content creation). 187

1.4. Exclusions 188

This Standard is limited to image contrast ratio measurements and defines contrast ratio as a relative metric and 189 measurement. 190

This Standard does not: 191

a) Include related factors such as display luminance, image size, or display resolution. 192

b) Prescribe actual white or black luminance levels of an image since those levels should be determined relative 193 to the ambient light level of the viewing environment. Image luminance levels should be addressed as part of 194 the system design process. 195

c) Apply to specialized systems that have their own standards such as medical imaging, broadcast, military, and 196 commercial movie theatres. In these and other specialized cases, contrast ratio criteria and measurement 197 procedures will deviate from the requirements and guidelines in this document. 198

d) Address contrast ratio required for digital cinema or home theater. The requirements of this viewing category 199 go beyond Full Motion Video to realize the artistic vision of the videographer or cinematographer. 200

2 International Organization for Standardization, Colorimetry ‐‐ Part 1: CIE Standard Colorimetric Observers, ISO/CIE 11664‐1:2019 (Vienna: International Commission on Illumination (CIE), 2019).



e) Apply to installations where there are large variations of uncontrollable ambient light because the 201 environment plays a role in the achievable contrast ratio of the system and the viewing category requirements 202 could not be met consistently. 203

204



2. REFERENCED PUBLICATIONS 205

2.1. Normative References 206

The following standards contain provisions that, through reference in this text, constitute provisions of this document. 207 At the time of approval, the editions indicated below were valid. Because standards are periodically revised, users 208 should consult the latest revision approved by the sponsoring Standards Developing Organizations: 209 210 There are no normative references for this standard. 211 212

2.2. Informative References 213

214 215

ISO/CIE 19476, Characterization of the performance of illuminance meters and luminance meters 216



3. DEFINITIONS 217

As used in this document, “shall” and “must” denote mandatory provisions of the Standard. “Should” denotes a 218 provision that is recommended, but not mandatory. 219

3.1. Definitions 220

For the purpose of this Standard, the following definitions apply: 221 222

a. 16‐zone Checkerboard: The test pattern made up of alternating black‐and‐white rectangles forming 16 223 equal zones in four rows. 224

225 b. 18% White Window Test Pattern: The test pattern with one 100% luminance‐level rectangle covering 18% 226

of the center of the pattern’s surface area used to measure the white luminance value. 227 228 c. Ambient Light on Screen: The illuminance level affecting the screen. 229

230 d. Black Level: The lowest level of luminance a system is capable of producing. 231

232 e. Brightness: The way light intensity is perceived by the human visual system. Referring to our experience 233

and impression of light, it is not a metric of its magnitude. As used in this Standard, the term brightness is 234 not to be confused with “brightness” controls on a display. 235

236 f. Center Line: A notional horizontal or vertical line that bisects the screen, referenced in the example 237

Viewing Area Plans provided in this Standard. Used for defining location of objects relative to the screen. 238 239

g. Closest Viewer: Viewer positioned at the shortest distance from the screen as defined by the viewing 240 area. 241

242 h. Contrast: Absolute difference in luminance between the peak white and black levels, where white and 243

black luminance are displayed either simultaneously or sequentially, per the respective test patterns. As 244 used in this Standard, the term “contrast” is not to be confused with “contrast controls” on a display. 245

246 i. Contrast Ratio: The numeric ratio of the highest and lowest luminance levels simultaneously or 247

sequentially present within an image per the respective test patterns. 248 249 j. Direct View Display: A display device that creates a directly viewable image by emitting light. 250

251 k. Farthest Viewer: Viewer positioned at the farthest distance from the screen as defined by the viewing 252

area. 253 254

l. Full Screen Black: The test pattern made up of one 0% luminance‐level (black) rectangle filling the whole 255 screen used to measure the black luminance value. 256

257 m. Illuminance: Light falling on a surface, measured in Lux (lx) or Foot‐Candle (ft‐c or fc) [1 lux = 0.09 fc]. It is 258

invisible to the human eye except in the form of reflected luminance. 259 260

n. Incident Light Meter: A type of light meter used to measure illuminance (i.e., ambient or environmental 261 light). It is also known as an illuminance meter. 262

263 o. Luminance: Light emitted or reflected from an object, measured in Candelas per square meter (cd/m2, 264

also referred to as a ‘nit’) or foot‐Lambert (fL). [1 nit = 0.292 fL]. 265 266



p. Plane of Display: Identification of image position on a plan or drawing relative to other plotted locations. 267 It is a notional line, whether in architectural drawing plan or elevation view, that aligns with the front 268 surface of the screen (i.e., image position) used as a datum to define viewers’ relative positions. 269

270 q. Screen: The surface the image is viewed on such as a projection screen or the light emitting side of a direct 271

view display. 272 273 r. Sequential Contrast Ratio: The difference in intensity between the “FULL ON” and “FULL OFF” intensities 274

of the display device. Contrast is measured in two separate tests. 275 276

s. Spot Photometer: A type of meter used to measure luminance. In this Standard the defined specification 277 of such meters includes an acceptance angle of 2° or less. 278

279 t. System Contrast Ratio: Contrast expressed as the function of the combination of a projector and screen 280

or direct view display and ambient light. 281 282

u. Viewer: A person with normal/corrected vision or normal visual acuity as defined in The International 283 Council of Ophthalmology 'Visual Acuity Measurement Standard' 1984. 284

285 v. Viewing Area: Volume of usable viewing space determined by application and design. 286

287 w. Viewing Area Plan: Plan view drawing of the viewing environment that identifies five viewing locations as 288

defined in the Requirements section of this Standard. 289 290



4. REQUIREMENTS 291

292 Minimum contrast ratios are defined based upon the proposed use or uses identified by the viewer. A system may 293 comprise one or more of these viewing requirement categories. The user of this Standard shall determine the 294 appropriate viewing requirement category contrast ratio or ratios before beginning measurement procedures. 295

4.1. Viewing Requirement Categories and Minimum Contrast Ratios 296

297 The four viewing requirement categories and their required minimum contrast ratios are as follows in 298 Figure 1: 299 300

Viewing Requirement Categories Checkerboard Contrast Ratio Sequential Contrast Ratio

Passive Viewing 7:1 7:1

Basic Decision Making 15:1 20:1

Analytical Decision Making 50:1 125:1

Full Motion Video 80:1 285:1

301 Figure 1: Minimum contrast ratios for viewing requirement categories 302

303 These contrast ratios shall be achieved within the viewing areas defined by the usable space and application. 304

305 The minimum contrast ratios shall be achieved at five points of measurement. Measurement locations are defined in 306 Section 4.3. 307 308 Luminance measurements shall be taken under conditions that reflect the conditions at time of application or under 309 conditions that simulate the application environment (i.e., if projecting at night, test at night. If viewers are seated, take 310 measurements at seated positions). 311

4.2. Viewing Area Plan 312

A viewing area plan shall be prepared and shall identify: 313

a) Image width and height; 314

b) Center of image (horizontal center line of screen); 315

c) Plane of screen (vertical center line of screen); 316

d) Height of center of screen from floor; and 317

e) Five viewing locations with identified distances to plane of screen and center line of screen. 318

4.3. Measurement Locations 319

The viewing location positions shall be defined as follows: 320

1. Viewing Location 1: Viewing location closest to the screen and farthest to the left in the plan view. 321

2. Viewing Location 2: Viewing location closest to the screen and farthest to the right in the plan view. 322

3. Viewing Location 3: Viewing location at the central point of viewing locations 1, 2, 4 and 5. In the case where 323 this central viewing location is obstructed (e.g., by a conference table) the measurement location shall be the 324 first available viewing location on the screen center line behind the obstruction. 325

4. Viewing Location 4: Viewing location farthest from the screen and farthest to the left in the plan view. 326

5. Viewing Location 5: Viewing location farthest from the screen and farthest to the right in the plan view. 327



6. 328

Figure 2: Viewing locations 329 330

These points shall be within the specified measurement range of the meter. 331

At each of the five viewing locations identified, 18 luminance measurements shall be taken (16 from the 16‐zone 332 checkerboard pattern and 2 from the sequential test patterns), ensuring that each measurement is taken at the eye 333 level for the viewer. 334

4.4. Image System Measurement Procedure 335

4.4.1. Measurement Prerequisites 336

The image system shall meet the following criteria: 337

a) The screen/display shall be installed according to the designer’s and manufacturer’s specifications. 338

b) Luminaires shall be on and functioning. If a room dimming system is present, the lighting scene for typical 339 room use should be selected. 340

4.4.2. Projection System Setup 341

If a projection system is used, then the projector shall be set up and operating as it would be for intended usage. The 342 following items shall be checked and adjusted according to the manufacturer’s procedures: 343

a) Ensure that the projector light source reaches standard operating temperature according to manufacturer’s 344 recommendations; 345

b) Check image size and geometry; 346

c) Select projector’s internal color settings as required (or perform colorimetry calibration per industry or 347 manufacturer recommended procedure); 348

d) Set pixel clock and phase as required; 349

e) Use a PLUGE (picture line‐up generation equipment) pattern (or similar) to set proper black level (point at 350 which pixels illuminate out of black); and 351

f) Use a grayscale pattern to set proper white level (point at which pixels dim out of full white). 352



Iteratively check items above as required. 353

4.4.3. Direct View Display System Setup 354

If a direct view system is used, then the direct view display shall be set up and operating for intended use. The following 355 items shall be checked and adjusted according to manufacturer’s procedures: 356

a) The display illumination shall reach standard operating temperature according to manufacturer’s 357 recommendations; 358

b) Verify that display is set at its native resolution and has no underscan/overscan to ensure proper test pattern 359 appearance; 360

c) When possible, disable any settings that turn the backlights off when a fully black video image is present. 361

d) Select display’s internal color settings as required so that white matches the color space being used (or perform 362 colorimetry calibration according to the manufacturer’s instruction or an otherwise recognized procedure); 363

e) Set pixel clock and phase as required; 364

f) Use a black PLUGE (picture line‐up generation equipment) pattern (or similar) to set black level (point at which 365 pixels illuminate out of black); and 366

g) Use a white PLUGE pattern to set white level (point at which pixels descend out of full white). 367

Iteratively check items above as required. 368

4.4.4. Equipment Requirements 369

The following shall be used for the measurement procedures outlined in this standard: 370

1. A luminance meter or spot photometer with up‐to‐date calibration, and with spectral luminance response of 371 the CIE standard observer3 with photopic vision. The measurement angle of the meter shall be 2° or less. 372

2. Completed viewing area plan. 373

3. 16‐zone black‐and‐white checkerboard test pattern (four columns by four rows). 374

4. The 18% white window and full‐screen black sequential test patterns. 375

5. Measurement form. 376

6. Tape measure or rangefinder. 377

7. A tripod to eliminate human factors of inaccuracy in test measurements. 378

4.5. Measurement Procedure 379

Contrast measurement shall follow the procedure below using the 16‐zone black‐and‐white checkerboard, the 18% 380 white window, and the full‐screen black patterns. 381 382 This procedure shall be documented for each lighting environment that may be required of a venue based on the 383 viewing category requirements. 384

385 Step 1 Display a 16‐zone black and white checkerboard test pattern on the screen (as illustrated in Figure 3 386

below) under conditions that represent actual viewing conditions. 387 388 Step 2 From the first measurement position identified on the viewing area plan (Viewing Location 1), measure 389

and record the luminance values at the center of each of the eight white rectangles. 390 391 Step 3 From the same measurement position, measure and record the luminance values at the center of each of 392

the eight black rectangles. 393

3 As defined in ISO/CIE 11664‐1:2019.



394 Step 4 Calculate the average of the eight white measurements and the average of the eight black 395

measurements. 396 397

Step 5 Divide the resulting average white value by the average black value to obtain the contrast ratio at that 398 measurement position. 399 400

Contrast Ratio = Luminance average white / Luminance average black 401 402

403

Figure 3 ‐ 16‐zone checkerboard pattern 404 405

Step 6 Repeat the contrast measurement procedure at each of the five measurement positions identified on the 406 Viewing Area Plan. 407

408 Step 7 Record the resulting contrast ratios for each of the measurement positions on the Viewing Area Plan and 409

determine if they meet the conformance requirements defined in Section 4.1. 410

Viewing Requirement Category Checkerboard Contrast Ratio

Passive Viewing 7:1

Basic Decision Making 15:1

Analytical Decision Making 50:1

Full Motion Video 80:1

411 412

Step 8 Determine sequential contrast ratio. Measure and record the 18% white window pattern at each of the 413 measurement positions identified on the Viewing Area Plan. 414

415 416

417

Figure 4: White window test pattern 418 419

Step 9 Measure and record the full‐screen black test pattern at each of the measurement positions identified on 420 the Viewing Area Plan. 421 422

423



424 Figure 5: Full‐screen black test pattern 425

426 Step 10 Divide the resulting white value by the black value to obtain the sequential contrast ratio for a given 427

viewing location. 428 429

Step 11 Verify that the luminance does not exceed the requirements for that viewing category as defined in 430 Section 4.1. 431

432

Viewing Requirement Category Sequential Contrast Ratio

Passive Viewing 7:1

Basic Decision Making 20:1

Analytical Decision Making 125:1

Full Motion Video 285:1

433 Step 12 Record the resulting contrast ratio for each of the measurement positions on the Viewing Area Plan. 434

435 Step 13 Determine conformance as defined in Section 5. 436



5. VERIFICATION 437

438 Verification of conformance to this Standard includes completed measurements of the contrast ratio at the five 439 locations identified on the Viewing Area Plan using the required measurement procedure and mandatory image system 440 criteria, previously defined in Section 4 (Requirements) of this Standard. 441 442 Based on the contrast ratio determined by the documented measurement results, the image system: 443 444

CONFORMS: If contrast ratios at all five measurement (viewing) locations meet or exceed the contrast ratios 445 required by the identified viewing category. 446 447 FAILS TO CONFORM: If the contrast ratio at any one of the measured locations falls below the identified 448 viewing category. Should the space fail to conform, probable cause(s) shall be noted on the measurement 449 form. 450

451



452



ANNEX A — EXAMPLES OF VIEWING AREA PLANS 453

The diagrams below show examples of Viewing Area Plans with dimensions recorded as part of the measurement 454 procedure. 455 456 457

458 459

Figure 6: Viewing Area Plan – Classroom 460 461 462



463

464 465

Figure 7: Viewing Area Plan – Meeting Room 466 467 468 469

470 471

Figure 8: Viewing Area Plan‐ Huddle/Screening Room 472



6. ANNEX B — SAMPLE FORMS (INFORMATIVE ANNEX) 473

Sample Measurement Conformance Form 474

475 Date of Test: Location: C conform

F fail

Client: Tester:

Viewing Category: Light Meter & Calibration Date:

16‐Zone Checkerboard Test Pattern Contrast Ratio

Viewing Location 1

White 1

White 2

White 3

White 4

White 5

White 6

White 7

White 8

Avg Contrast C conform

F fail

Luminance

Black 1

Black 2

Black 3

Black 4

Black 5

Black 6

Black 7

Black 8

Luminance

Viewing Location 2

White 1

White 2

White 3

White 4

White 5

White 6

White 7

White 8


F fail

Luminance

Black 1

Black 2

Black 3

Black 4

Black 5

Black 6

Black 7

Black 8

Luminance

Viewing Location 3

White 1

White 2

White 3

White 4

White 5

White 6

White 7

White 8


F fail

Luminance

Black 1

Black 2

Black 3

Black 4

Black 5

Black 6

Black 7

Black 8

Luminance

Viewing Location 4

White 1

White 2

White 3

White 4

White 5

White 6

White 7

White 8


F fail

Luminance

Black 1

Black 2

Black 3

Black 4

Black 5

Black 6

Black 7

Black 8

Luminance

Viewing Location 5

White 1

White 2

White 3

White 4

White 5

White 6

White 7

White 8


F fail

Luminance

Black 1

Black 2

Black 3

Black 4

Black 5

Black 6

Black 7

Black 8

Luminance

476 477



478 Sequential test pattern (18% white window & full‐

screen black patterns) Contrast Ratio

Viewing Location 1

White Contrast C conform

F fail

Luminance

Black

Luminance

Viewing Location 2


F fail

Luminance

Black

Luminance

Viewing Location 3


F fail

Luminance

Black

Luminance

Viewing Location 4


F fail

Luminance

Black

Luminance

Viewing Location 5


F fail

Luminance

Black

Luminance

479

CONFORMANCE RESULT CONFORMS

FAILS TO CONFORM

480 Explanation &

Notes:

481

482



Sample Form with Optional Detailed System Information 483

Although this form exceeds the requirements of this Standard, should the system fail to conform, additional information 484 may prove to be a valuable analysis tool for potential remediation. 485 486

Checkerboard Viewing Location Contrast Ratios: 1) __:__ 2) __:__ 3) __:__ 4) __:__ 5) __:__Sequential Viewing Location Contrast Ratios: 1) __:__ 2) __:__ 3) __:__ 4) __:__ 5) __:__

Display Device

Make and model

Type of device (projector, direct view LED, etc.)

Rated light output

Native pixel resolution

Projector lens throw ratio or distance (if applicable)

Lamp hours elapsed (if applicable)

Lens model (if applicable)

Comments

Projection Screen (if applicable)

Make and model

Front/rear

Type of material

Aspect ratio of screen

Image height

Image width

Focal length (if Fresnel type)

Comments

Lighting

General description

Lighting type near the screen

Is lighting near the screen independently controllable?

Main room or working area lighting description: type; dimmable? Pre‐set lighting levels and/or scenes?

Number of lighting scenarios to be measured

Room

Primary purpose of room

Possible hours of use (time of day)

Room dimensions + ceiling height

Description of room, including color and main surfaces

Distance of closest viewer to screen

Distance of farthest viewer to screen

Angle of end seat, front row, to screen center (plan view)

Windows and known influences on screen

Type of window coverings and control (e.g., manual, powered, etc.)



7. ANNEX C — VIEWING REQUIREMENT CATEGORIES ‐ EXTENDED 487

INFORMATION (INFORMATIVE) 488

When AVIXA (formerly InfoComm International) initiated development of this Standard, one of the initial tasks was to 489 define viewing requirement categories with strong definitions using defensible metrics against which minimally 490 acceptable contrast ratios could be defined, based on the intended purposes for which an image could be used. Multiple 491 categories were deemed appropriate with the next steps being to determine the quantity of categories necessary and 492 the associated definitions that this Standard would require. 493 494 Group deliberations included practical tests under controlled conditions with a panel of subject matter experts. The 495 group consulted additional research and publications. This initial panel and both the initial direct view display contrast 496 ratio panel and this current panel reached unanimous agreement on both the quantity of viewing categories and their 497 definitions. 498

499 500 A. Passive Viewing 501 502 The viewer should be able to recognize what the images are and separate the text or the main image from the 503 background under typical lighting for the viewing environment. The content does not require assimilation and retention 504 of detail, but the general intent is understood. There is passive engagement with the content (e.g., non‐critical or 505 informal viewing of content). 506 507 This is a minimally acceptable contrast ratio, primarily for passive presentations or passively watching images on a 508 display. 509 510 Passive viewing environments are locations where images are displayed to an audience as a means of providing informal 511 information. Business presentations may fall into this category if they are informally informational but not dependent 512 on a high level of detail. Digital signage often falls into this category. 513 514 In a passive viewing environment, ambient light may be high or uncontrollable and system contrast may be challenged 515 by features like task lighting, windows, bright (reflective) surfaces. 516 517 B. Basic Decision Making 518 519 The viewer can make basic decisions from the displayed image. The decisions are not dependent on critical details 520 within the image, but there is assimilation and retention of information. The viewer is actively engaged with the content 521 (e.g., information displays, presentations containing detailed images, classrooms, board rooms, multi‐purpose rooms, 522 product illustrations). 523 524 The viewer should be able to understand what is being communicated. Graphic images and text are legible to the 525 extent that the viewer can make basic decisions based on what they see. Decisions made are based on comprehending 526 the informational content itself and are not dependent on the resolution of every element of detail. 527 528 Basic decision‐making viewing applications include the presentation of photographs, detailed graphic images, product 529 illustrations, and information displays (such as airline departures, sports scores or stock quotes). In this scenario, the 530 information obtained from the image informs a basic decision by a fully engaged viewer. 531

532 In a typical basic decision‐making environment (e.g., classrooms, multi‐purpose rooms, board rooms), there may be 533 some degree of ambient light control, such as window shades and zoned task lighting. 534 535 C. Analytical Decision Making 536 537 The viewer is fully engaged with minute details present in the content and needs to be able to resolve every element 538 of the displayed image. Analytical decision‐making environments support professional assessments, such as the 539



examination of engineering or architectural drawings, electrical schematics, photographic images, forensic evidence, 540 or failure analysis. Decisions made are based on comprehending the content itself and are dependent on the resolution 541 of every element of detail. 542 543 Analytical decision‐making viewing environments typically have controllable ambient light – particularly on or by the 544 screen – often with darkened or anti‐reflective surfaces and highly focused task lighting. 545 546 Close attention to both the system design and environmental characteristics will be necessary to achieve the desired 547 contrast. 548 549 D. Full Motion Video 550 551 In this category, movies or other full motion videos are displayed in a controlled viewing environment with an audience 552 that has a high level of engagement with the content. The viewer can discern key elements present in the full motion 553 video, including detail provided by the cinematographer or videographer necessary to support the storyline and intent 554 (e.g., home theater, business screening room, business presentation content creation). 555 556 Most home theaters and business screening rooms would fall into this category. 557 558 NOTE: This category does not include professional or commercial digital cinema or Hollywood‐level film screening 559 rooms since the criteria for those rooms is more rigorous than is necessary for private rooms. The contrast ratio for 560 commercial digital cinema is established in other publications. 561

562



Viewing Requirement Categories Summary Chart 563

564

VIEWING CATEGORY

MINIMUM SYSTEM

CONTRAST RATIO

(CHECKERBOARD PATTERN)

MINIMUM SYSTEM

CONTRAST RATIO

(SEQUENTIAL PATTERNS)

VIEWER REQUIREMENTS

ENVIRONMENT –EXAMPLE

CHARACTERISTICS

EXAMPLES

Passive Viewing 7:1 7:1 Images and text distinguishable from background

Passive engagement with content

Assimilation and retention of detail not required

Informal viewing of content

May have little control of ambient light

Ambient light may be high

Task lighting may not be ideal

Windows may have insufficient blinds or curtains

May be reflective surfaces (e.g., furniture)

Retail stores, marketing or presentations of non‐critical or informal information

Basic Decision Making

15:1 20:1 Actively engaged with content

Assimilation and retention of detail

Images and text are legible to the extent that decisions can be made

Decisions based on content itself, not resolution of detail

Moderate control of ambient light

Ambient light may be moderately high

Task lighting recommended

Information displays, presentations containing detailed data and images (e.g., classrooms, meeting rooms, boardrooms, videoconferencing rooms, multi‐purpose rooms, product illustrations, transportation departures/arrivals)

Analytical Decision Making

50:1 125:1 Images and text contain finest detail

Assimilation, retention, and analysis of finest detail

Analytical image assessment

Mission‐critical image displays

Professional analysis of detail

Highly controlled environment

Controlled ambient light

Focused task lighting

No ambient light directly affecting screen, black‐out window treatments

Engineering and architectural drawings, electrical schematics, forensic evidence, failure analysis, photographic evaluation (e.g., courtrooms)

Full Motion Video

80:1 285:1 High level of engagement with content

Precisely controlled ambient light

Controlled viewing environment (e.g., home theater,



Films not viewed in a cinema

business screening room)

565

566



8. ANNEX D — RATIONALE FOR SEQUENTIAL TEST PATTERN (INFORMATIVE) 567

The original ANSI/INFOCOMM 3M‐2011 standard was entirely projection based and intended to accurately reflect the 568 performance of projection‐based systems. AVIXA initiated the development of this Standard to create a metric for 569 accurately gauging all AV systems and to guarantee performance and user experience minimums across a broad range 570 of environments and applications. 571

At its earliest point, the task group concluded that only checkerboard (intra‐frame) contrast measurements needed to 572 be used as they represented an average level of image luminance to allow for a broad range of use cases. Checkerboard 573 contrast measurement was common industry practice at the time due to its primary focus on projection technology 574 and the limits of projectors and available projection screens. 575

However, the standard evolved to encompass more advanced modern projection technology and now includes direct 576 view display technologies of all types. Sequential (also called full on/off or inter‐frame) contrast ratio testing is included 577 for two reasons: 578

1. To include high‐performance display technologies (quantum dot and OLED based flat panels and direct view 579 LED displays) that can create extremely high contrast ratios in a wider range of environments. By measuring 580 the sequential contrast ratio in addition to the checkerboard, we define the average of how the system will 581 perform (checkerboard) in daily use and measure system performance at its highest level (sequential). This 582 allows for a meaningful test of environmental impact in use cases such as totally dark rooms where differences 583 such as room reflection can have a noticeable impact or highly ambient lit rooms where images whose 584 checkerboard contrast ratios measure acceptably still appear “washed out.” Overall, a more accurate picture 585 of system performance is delivered, both in terms of maximum capability and average use. 586

2. To ensure that a system’s measurements will accurately reflect the performance as expected when this 587 Standard is applied. Requiring both checkerboard and sequential contrast measurements prevents display 588 device manufacturers from making modifications that appear to meet compliance tests when the actual 589 performance in daily use does not meet the expected level of performance. Numerous techniques are 590 employed to artificially increase contrast. For example, in a direct view LED display showing a full “black” 591 image, the LEDs are fully powered “off.” This can “game” the contrast ratio measurement, such that the display 592 responds differently to testing than it would to actual use. By combining both measurements, the result should 593 be more indicative of what the user will experience. The test methodologies span the entire range of possible 594 use cases and environmental conditions that can impact the user. 595

596

597 598 599



9. ANNEX E — BIBLIOGRAPHY (INFORMATIVE) 600

601 The following publications contain information that supports the design and application of this Standard, but are not 602 required provisions of the standard: 603 604

Barten, Peter G.J. Contrast Ratio Sensitivity of the Human Eye and Its Effects on Image Quality. Knegsel, 605 Netherlands: HV Press, 1999. 606

607 Blackwell, H. Richard. “Contrast Thresholds of the Human Eye.” Journal of the Optical Society of America 36, 608

no. 11 (1946): 624‐643. 609 610 Boynton, Paul A., Edward F. Kelley. “Stray Light Compensation in Small Area Contrast Measurements of 611

Projection Displays.” Society of Photo‐Optical Instrumentation Engineers Proceedings 4657 (April 612 2002). 10.1117/12.463788. 613

614 Digital Cinema Initiatives, LLC. Digital Cinema System Specification, Compliance Test Plan. Version 1.1. 615

Hollywood: DCI, 2009. https://www.dcimovies.com/archives/DCI_CTP_v1_1.pdf. 616 617 International Electrotechnical Commission. Electronic Projection – Measurement and 618

Documentation of Key Performance Criteria – Part 1: Fixed Resolution Projectors. IEC 61947‐1. 619 Geneva: IEC, 2002. 620

621 International Organization for Standardization. General Purpose and Photographic Exposure 622

Light Meters. ISO 2720:1974. Paris: ISO, 1974. 623 624

———. Photography – Projection in Indoor Rooms – Part 2: Screen Luminance Test for Still 625 and Video Projection. ISO 11315‐2 Paris: ISO, 1997. 626

627

———. Photography – Projection in Indoor Rooms – Part 3: Classification of Transmitting 628 Projection Screens and Measurement of Their Transmitted Luminance Levels. ISO 11315‐3. Paris: ISO, 629 1997. 630

631 National Electrical Manufacturers Association. Digital Imaging and Communications in Medicine 632

(DICOM) PS 3.14‐2009 Part 14: Grayscale Standard Display Function. Rosslyn, VA: NEMA, 2009. 633 634 Peli, Eli. “Contrast in Complex Images.” Journal of the Optical Society of America 7, no. 10 (October 1990): 635

2032‐2040. 636

637

Documents

AVIXA V201.01:201X Image System Contrast Ratio …...154 to measure luminance reflected from, or transmitted through, the projection screen or as measured from the face of 155 the