北京理工大學(xué)數(shù)碼相機性能評測試驗一視覺分辨率及空間頻率響應(yīng)SFR測試

1、數(shù)碼相機性能評測實驗一視覺分辨率及空間頻率響應(yīng)（SFR）測試實驗?zāi)康模?、理解數(shù)碼相機視覺分辨率的定義及其度量單位。2、了解數(shù)碼相機分辨率測試標(biāo)準(zhǔn)ISO12233以及GB/T 19953-2005數(shù)碼相機 分辨率的測量，熟悉測試標(biāo)板構(gòu)成，掌握其使用方法。3、掌握數(shù)碼相機視覺分辨率測試方法，能夠通過目視判別數(shù)碼相機的分辨率特 性。4、了解數(shù)碼相機空間頻率響應(yīng)（SFR的測試原理，理解空間頻率響應(yīng)（SFR 曲線的含義。5、掌握數(shù)碼相機空間頻率響應(yīng)（SFR的測試方法,能夠通過 SFR曲線判別數(shù) 碼相機的分辨率特性。實驗要求：1、使用數(shù)碼相機拍攝ISO12233標(biāo)準(zhǔn)分辨率靶板，要求連續(xù)拍攝三幅圖。2、目

2、視判別數(shù)碼相機的視覺分辨率，需分別判別水平、垂直、和斜 45度方向 的視覺分辨率（注意：若拍攝的靶板有效區(qū)域高度僅占據(jù)相機幅面高度的一 部分，需將目視判別結(jié)果乘以修正系數(shù)以得到真實的測量結(jié)果。修正系數(shù)=以像素為單位的相機幅面高度/以像素為單位的靶板有效區(qū)域高度）。3、使用Imatest軟件測量數(shù)碼相機空間頻率響應(yīng)（SFR曲線，需分別測量水 平及垂直方向的SFR并取MTF50 MTF20乍為測量結(jié)果，與視覺分辨率測 試結(jié)果進行比較。1、使用數(shù)碼相機拍攝ISO12233標(biāo)準(zhǔn)分辨率靶板，要求連續(xù)拍攝三幅圖 第一張圖第二張圖QA-72-PRM第三張圖6 7 flu 0146 8。T 121 一二二B

3、&伯母14 I-二二二-IT8-r6二三=1I<B1=VVV4-I;T1 2 3 4 5 G 7 a 9 O-1:.718 電二二 b 7 0 92、目視判別數(shù)碼相機的視覺分辨率，需分別判別水平、垂直、和斜 45度方向的視覺分辨率第一張圖的截圖：水平條測中心垂直視覺分辨率對角線條測斜向上450視覺分辨率第二張圖的截圖:豎直條測中心水平分辨率4 12 10 8水平條測中心垂直視覺分辨率12對角線條測斜向上450視覺分辨率相機型號iPhone5123平均值水平方向視覺分辨率1450128013301320垂直方向視覺分辨率1240122012601240斜向上450視覺分辨率>

4、900>900>900>900實驗人員實驗日期2014.11.17騏圍機 照相機窗膻商 電相機型號 光圈值 喘母洞 工即速度 曝光補償 焦距口 I 、產(chǎn) IEJ 用求立圖 則先模式 目標(biāo)5崎 閃光燈模式 閃光m纏 35mm陣踞pple iFhone 5 f/2 4 1730 秒 ISO-50 0步驟 ，套案酶無閃光，強制23明確相機型號、相機基本設(shè)置。3、使用Imatest軟件測量數(shù)碼相機空間頻率響應(yīng)(SFR曲線，需分別測量水 平及垂直方向的SFR并取MTF50 MTF20乍為測量結(jié)果，與視覺分辨率測試結(jié) 果進行比較。過程由黑到白由白到黑次數(shù)1垂直 方向2垂直 方向3 水平

5、方向4水平 方向5垂直 方向6垂直 方向7水平 方向8水平 方向分辨率(LW/PH)10881172158515421265130412441151均值(LW/PH)1130156412851198第一次目視(LW/PH)1240145012401450實驗運行結(jié)果依次如下:23-Nov-2014 17:31:27Edge profile: Horizontal-3264 x 2448 pixels (WxH)7.99 MpxlsIMG_2250.JPGtaoxpn pkrorp eadEIf aenn prorp ea3ELbTRFS-6Edge -6.85 degsImatest 4.0.

6、15 Image Sensor ，rif-ROI: 100x440 pixels 27% above ctr/-channel (YA27)Gamma = 0.5010-90% rise = 2.35 pixels=1042 per PHRGB rise = 2.38 2.35 2.28 pxlsRMS Edge roughness = 0.0745 pxlsChart contrast = 10Gamma (from chart) = 0.755Lt, dk lvls = 217.2, 38.2 Lt/dk = 5.68-4-2024Pixels (Horizontal)100.80.6MT

7、F50 = 0.222 Cy/Pxlxl0.40.2Nyquist fMTF: Horizontal w/NR0Purchase at wwFmOeEvaluation5ve rsftCT= 1088 LW/PHUndersharpening 29.2%00.8Edge angle = -6.85 degsEstm. chart contrast = 32.3Selected EXIF dataMTF50 = 0.222 Cy/Pxl |=1088 LW/PHI(RGB) = 0.22 0.222 0.23 Cy/P xlFrequency, Cycles/pixelIMG

8、2250.JPGEdge profTfe: Horizontal2014 弓都"Edge -6.83 degsY-channel (YA21)Gamma = 0.503264 x 2448 pixels (WxH)7.99 Mpxls-ROI: 100x238 pixels 21% above ctr10-90% rise = 2.09 pixels=1172 per PHRGB rise = 2.1 2.09 2.03 pxlsRMS Edge roughness = 0.0739 pxlsChart contrast = 10Gamma (from chart) = 0.75Lt

9、, dk lvls = 217.1, 38.6 Lt/dk = 5.62Imatest 4.0.15 Image Sensorrrr-4-20246810Pixels (Horizontal)IIILLI iMTF50 = 0.254 Cy/Pxl-= 1241 LW/PH(RGB)= 0.252 0.252 0.263 Cy/P xl- EvaluatiMT怦0VersiOP = 1241 LW/PH-、Undersharpening 24.7%MTF50 = 0.254 Cy/Pxl-, MTF20 = 0.423 Cy/Pxl一 Purchas't wwwnmae跟.oom.Ny

10、quist f-MTF: Horizontal w/NR_0.81ROI: 100x440 pixelsL R T B = 1680 1779 460 899imatestROI: 100x238 pixelsL R T B = 1664 1763 691 928Edge angle = -6.83 degsEstm. chart contrast = 31.6Selected EXIF dataIEdge profile: Vertical-4-20246810Pixels (Vertical)ROI: 363x87 pixelsL R T B = 1435 1797 13

11、70 1456IMG 2250.JPG23-Nov-2014 17:42:22Edge 6.14 degsImatest 4.0.15 Image Sensor3264 x 2448 pixels (WxH)7.99 Mpxls_Y-channel (YB9) Gamma = 0.50-ROI: 363x87 pixels9.3% below ctr10-90% rise = 1.59 pixels=1537 per PHRGB rise = 1.6 1.59 1.6 pxlsRMS Edge roughness = 0.0741 pxlsChart contrast = 10Gamma (f

12、rom chart) = 0.841Lt, dk lvls = 210.7, 30.4 Lt/dk = 6.93faenn p.f.orp e adE-60.20Edge angle = 6.14 degsEstm. chart contrast = 48Selected EXIF dataIMG 2250.JPGEdge profile: Vertical3264 x 2448 pixels (WxH) 7.99 Mpxls23-Nov-2014 17:45:1210-90% rise=1.66 pixelsImatest 4.0.15 Image Sensor trI*

13、i-ROI: 280x155 pixels 11% below -R of ctrY-channel (YBR11)Gamma = 0.50Edge 6.35 degs=1473 per PHRGB rise = 1.66 1.66 1.66 pxlsRMS Edge roughness = 0.0809 pxlsChart contrast = 10Gamma (from chart) = 0.848Lt, dk lvls = 212.1, 30.1 Lt/dk = 7.05MTF50 = 0.324 Cy/Pxl= 1585 LW/PH(RGB) = 0.325 0.323 0.325 C

14、y/P xlEvaluation5ve rs2or= 1585 LW/PH一Undersharpening 17.1%MTF50 = 0.324 Cy/PxlMTF20 = 0.479 Cy/PxlPurchase abwwwTFrotiNytes=t0(?om一Nyquist fMTF: Vertical w/NR一00.8Frequency, Cycles/pixelMTF50 = 0.315 Cy/Pxl、=1542 LW/PH"、(RGB) = 0.317 0.313 0.316 Cy/P xl-'Evaluatio汴0vergionr= 1542

15、LW/PHUndersharpening 18.0% MTF50 = 0.315 Cy/PxlMTF20 = 0.476Cy/Pxl-Purchase atwvFanatetst. 1>om、Nyquist fMTF: Vertical w/NR0.8。imatestIMG_2250.JPGEdge profile: Horizontal-3264 x 2448 pixels (WxH)7.99 Mpxls23-Nov-2014 17:23:46xlraenn ArkTOTP eoaE-ROI: 169x294 pixels22% above ctr_Y-channel

16、 (YA22)Gamma = 0.50Edge -6.61 degs10-90% rise = 2.10 pixels=1168 per PHRGB rise = 2.21 2.11 1.84 pxlsRMS Edge roughness = 0.0845 pxlsChart contrast = 10Gamma (from chart) = 0.743Lt, dk lvls = 217.3, 39.3 Lt/dk = 5.53Imatest 4.0.15 Image SensorIIFROI: 169x294 pixelsL R T B = 1533 1701 636 929-6-4-210

17、0.8Pixels (Horizontal)MTF50 = 0.266 Cy/Pxl=1304 LW/PH(RGB)= 0.264 0.266 0.277 Cy/P xlEdge angle = -6.61 degsEstm. chart contrast = 30.6Selected EXIF dataLrTRFSEvaluatMTFFV eftC/P= 1304 LW/PHUndersharpening 24.6%MTF50 = 0.266 Cy/PxlMTF20 = 0.421 Cy/PxlPurchaseat wwwdmauestcomMTF: Horizontal

18、w/NR0.20.4Nyquist f0.60.8Frequency, Cycles/pixel。imatestIMG_2250.JPGEdge profile: Horizontal23-Nov-2014 17:26:05faenn prkTOTP eadE-3264 x 2448 pixels (WxH)7.99 MpxlsY-channel (YA23)Gamma = 0.50Edge -6.6 degs-ROI: 126x418 pixels 23% above ctr10-90% rise = 2.21 pixels=1108 per PHRGB rise = 2.32 2.21 1

19、.94 pxlsRMS Edge roughness = 0.083 pxlsChart contrast = 10Gamma (from chart) = 0.752Lt, dk lvls = 217.2, 38.5 Lt/dk = 5.65-6-4-20Imatest 4.0.15 Image SensorIIF6810LbTMVRFSPixels (Horizontal)0.2Nyquist fMTF: Horizontal w/NRMTF50 = 0.258 Cy/Pxl=1265 LW/PH(RGB) = 0.256 0.258 0.267 Cy/P xlEval

20、uatiorv e恃kC/P= 1265 LW/PHUndersharpening 25.6%0.8Edge angle = -6.6 degsEstm. chart contrast = 31.9Selected EXIF dataMTF50 = 0.258 Cy/PxlMTF20 = 0.407 Cy/PxlPurchasdat wwwdmaetst&QmROI: 126x418 pixelsL R T B = 1558 1683 537 954Edge profile: VerticalIMG_2250.JPGp3264 x 2448 pixels (WxH)7

21、.99 MpxlsLt, dk lvls = 210.1, 30.4 Lt/dk = 6.91Imatest 4.0.15 Image Sensor23-Nov-2014 17:47:11ROI: 216x117 pixels 15% below ctrY-channel (YB15)Gamma = 0.50Edge 5.91 degs10-90% rise = 2.04 pixels=1202 per PHRGB rise = 2.09 2.03 2.08 pxlsRMS Edge roughness = 0.0779 pxlsChart contrast = 10Gamma (from c

22、hart) = 0.84-6-4-20246810Pixels (Vertical)ROI: 216x117 pixelsL R T B = 1415 1630 1443 1559MTF50 = 0.254 Cy/Pxl=1244 LW/PH(RGB) = 0.252 0.252 0.268 Cy/P xlEdge angle = 5.91 degsEstm. chart contrast = 47.8Selected EXIF data EvaluatiOTTVe rs50CT= 1244 LW/PHUndersharpening 23.2%MTF50 = 0.254 Cy/Pxl0.2MTF20 = 0.408 Cy/P,Purchas*t wwwTFmNxlNyquist fMTF: Vertical w/NRL=00Frequency, Cycles/pixel_L0.81。imatestIMG 2250.JPG3264 x