How International Standards affect Camera Testing October 2008

Transcription

1 How International Standards affect Camera Testing October

2 In the beginning When I started testing cameras in 1997 I sat there and asked myself: how the hell shall I do that? 2

3 The unlimited number of standards Isn t there a standard method how to test cameras? There are several: ISO 12231: Terminology ISO 12232: Determination of ISO speed ISO 12233: Resolution measurements ISO 12234: Removable memory Part 1: Basic removable memory reference model Part 2: data format - TIFF/EP ISO 14524: Methods for measuring opto-electronic conversion functions (OECF) ISO 15739: Noise measurements ISO 15740: Picture Transfer Protocol (PTP) for Digital Still Photography Devices 3

4 The unlimited number of standards ISO 15781: Measuring shooting time lag, shutter release time lag, shooting rate, and start-up time ISO 17321: Graphic technology and photography Colour characterisation of digital still cameras Part 1: Stimuli, metrology, and test procedures ISO 20462: Psychophysical experimental method to estimate image quality Part 1: Overview of psychophysical elements Part 2: Triplet comparison method Part 3: Quality ruler method ISO Extended colour encodings for digital image storage, manipulation and interchange Part 1: Architecture and requirements Part 2: ROMM RGB Part 3: RIMM RGB Part 4: ECI RGB 4

5 The unlimited number of standards Standardisation committees: International Organization for Standardization (ISO) Technical Commitee (TC) 42, Working Group 18 Cell Phone Quality Group organized by International Imaging Industry Association (I3A) International Electrotechnical Commission (IEC) Technical Commitee (TC) 100 Related Organisations: ICC, CIE, SMPTE 5

6 Values which can be measured: Resolution (s) Dynamic Range (s) Used digital values (s) Noise (s) Color Reproduction (s) White Balance (s) Vignetting (s) Distortion (s) Power consumption Dead Pixels 6

7 Values which can be measured: Max. scaling Flash uniformity and guide number Lateral chromatic aberration (s) Color shading Noise based on human perception (s?) Shutter and shooting lag (s?) Startup time and shooting rate (s?) stabilization (s?) 7

8 Principle 8

9 Principle 9

10 Standards are not God given Several problems occured 10

11 Standards are not God given Several problems occured 11

12 resolution measurement 12

13 Finding new methods Signal to noise vs. Visual noise SNx= 27 SNx= 29 13

14 color reproduction quality 14

15 color reproduction quality 15

16 color reproduction quality 16

17 shutter and shooting lag 17

18 Welcome: Steve ( Stabilizer Evaluation Equipment ) 18

19 19

20 OECF, Speed, and Noise (ISO 14524, 15739) 20

21 OECF, Speed, and Noise (ISO 14524, 15739) 21

22 vignetting / corner shading 22

23 vignetting / corner shading 23

24 distortion 24

25 chromatic aberration 25

26 power consumption test 26

27 power consumption and shooting rate Reihe Reihe1 Reihe

28 max. scale 28

29 Flash: uniformity and guide number Ze ile 1,00 0,90 0,80 0,90-1,00 0,70 y Log Lum inanz 1,08 1,97 2,97 0,80-0,90 0,70-0,80 0,60 0,60-0,70 0,50 0,50-0,60 0,40 0,40-0,50 0,30-0,40 0,30 0,20-0,30 0,20 0,10-0,20 0,10 R25 0,00-0,10 R17 40 R R ,00 Log Lum inanz 3 0,67 4 1,46 5 1,92 6 2,16 Differenz Ble nde ns tufen 29

30 resolution measurement 30

31 resolution measurement 31

32 resolution measurement 32

33 Measuring spectral sensitivities 33

34 Measuring spectral sensitivities Nikon D70 spectral response 1,2 rel. spectral response 1,0 R_IF G_IF B_IF R_LED G_LED B_LED R_mono G_mono B_mono 0,8 0,6 0,4 0,2 0, wavelength [nm] 34