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1、数码相机性能评测实验视觉分辨率及空间频率响应（SFR测试实验目的：1、理解数码相机视觉分辨率的定义及其度量单位。2、了解数码相机分辨率测试标准ISO12233以及GB/T 19953-2005数码相机 分辨率的测量，熟悉测试标板构成，掌握其使用方法。3、掌握数码相机视觉分辨率测试方法，能够通过目视判别数码相机的分辨率特 性。4、了解数码相机空间频率响应（SFR的测试原理，理解空间频率响应（SFR 曲线的含义。5、掌握数码相机空间频率响应（SFR的测试方法，能够通过 SFR曲线判别数 码相机的分辨率特性。实验要求：1、使用数码相机拍摄ISO12233标准分辨率靶板,要求连续拍摄三幅图。2、目视判
2、别数码相机的视觉分辨率，需分别判别水平、垂直、和斜 45 度方向 的视觉分辨率 （ 注意：若拍摄的靶板有效区域高度仅占据相机幅面高度的一 部分，需将目视判别结果乘以修正系数以得到真实的测量结果。修正系数 = 以像素为单位的相机幅面高度 /以像素为单位的靶板有效区域高度 ）。3、使用 Imatest 软件测量数码相机空间频率响应（ SFR 曲线，需分别测量水 平及垂直方向的SFR并取MTF50 MTF20乍为测量结果，与视觉分辨率测 试结果进行比较。1、使用数码相机拍摄ISO12233标准分辨率靶板,要求连续拍摄三幅图 第一张图I J r J1GTJ2 J 4:丿 -i卜! _?l 3 y QI
3、CL5rT2m=e二 0,=T2=苗 m 二勿t严勺-9岀f E9 L I n II II I三3 1 i 1 tA-|M I M M I 11 14 12 10 ft 水平条测中心垂直视觉分辨率1012竖直条测中心水平分辨率8/9对角线条测斜向上45视觉分辨率第三张图的截图:4 12 10 8水平条测中心垂直视觉分辨率101214竖直条测中心水平分辨率对角线条测斜向上45视觉分辨率相机型号iPhone5123平均值水平方向视觉分辨率1450128013301320垂直方向视觉分辨率1240122012601240斜向上45视觉分辨率900900900900实验人员实验日期2014.11.17
4、明确相机型号、相机基本设置。照相机制苣商Apple理相机型号iPhone 5光圖值f/2.4曝光时a1/30 秒工別谨度iso-sa嗯光补偿0步豔焦距4 S米履犬进圈测光欖式碧目标?福丙光灯捕式无闷光】闪划ns33强制3、使用Imatest软件测量数码相机空间频率响应(SFR曲线，需分别测量水 平及垂直方向的SFR并取MTF50 MTF20乍为测量结果，与视觉分辨率测试结 果进行比较。过程由黑到白由白到黑次数1垂直 方向2垂直 方向3水平 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(L
5、W/PH)1130156412851198第一次目视(LW/PH)1240145012401450实验运行结果依次如下:IMG 2250.JPG0.2Nyquist fMTF: Horiz ontal w/NR00.81Io inwtEHj023-Nov-2014 17:31:27XLtIMVRFae e o pEEdge p rofile: Horiz ontalEdge -6.85 degsImatest 4.0.15 Image Se nsor3264 x 2448 p ixels (WxH)7.99 Mp xlsY-cha nnel (YA27)Gamma = 0.5010-90% r
6、ise = 2.35 p ixels =1042 per PHRGB rise = 2.38 2.35 2.28 p xlsRMS Edge rough ness = 0.0745 pxlsChart con trast = 10Gamma (from chart) = 0.755Lt, dk lvls = 217.2, 38.2 Lt/dk = 5.68ROI: 100x440 pixels27% above ctr-6-4-2024Pixels (Horizontal)10MTF50 = 0.222 Cy/Pxl=1088 LW/PH(RGB) = 0.22 0.222 0.23 Cy/P
7、 xl0.80.6MTF50 = 0.222 Cy/PxlMT.F20 = 0xl0.40.2Nyquist fMTF: Horizo ntal w/NR0.810.20.40.6Freque ncy, Cycles/pixelEvaluationwersitCf= 1088 LW/PHUn dersharpe ning 29.2%IMG 2250.JPGEdge profile: Horizorbta3264 x 2448 p ixels (WxH)7.99 Mp xlsEdge -6.83 degs_Y-cha nnel (YA21)Gamma = 0.5010-90% rise = 2.
8、09 pixels=1172 per PHRGB rise = 2.1 2.09 2.03 p xlsRMS Edge rough ness = 0.0739 pxlsChart con trast = 10Gamma (from chart) = 0.75Lt, dk lvls = 217.1, 38.6 Lt/dk = 5.62-ROI: 100x238 pixels21% above ctrV|2014 17:33:19-6-4-2Imatest 4.0.15 Image Se nsorBrrr210Pixels (Horiz on tal)Selected EXIF data0.80.
9、6MTF50 = 0.254 Cy/Pxl0.4MTF50 = 0.254 Cy/Pxl=1241 LW/PH(RGB) = 0.252 0.252 0.263 Cy/P xlEvaluationverson = 1241 LW/PHUn dersharpe ning 24.7%-Purchas丄MTF20 = 0.423 Cy/Pxlat www；Fmaetsi0.Gom0.20.40.6Frequency, Cycles/ pixelROI: 100x440 p ixelsL R T B = 1680 1779 460 899Edge an gle = -6.85 degsEstm. ch
10、art con trast = 32.3Selected EXIF dataROI: 100x238 pixelsL R T B = 1664 1763 691 928Edge an gle = -6.83 degsEstm. chart con trast = 31.6IMG 2250.JPGJ III -Edge p rofile: Vertical23-Nov-2014 17:42:22yfaen mf pp eaaEmvbff aen i ye r pp eadEdge 6.14 degsImatest 4.0.15 Image Se nsor.Y-cha nnel (YB9)Gamm
11、a = 0.503264 x 2448 p ixels (WxH)7.99 Mp xlsLt, dk lvls = 210.7, 30.4 Lt/dk = 6.93ROI: 363x87 p ixels9.3% below ctr10-90% rise = 1.59 p ixels =1537 per PHRGB rise = 1.6 1.59 1.6 p xlsRMS Edge rough ness = 0.0741 pxlsChart con trast = 10Gamma (from chart) = 0.841-6-4-20 2Pixels (Vertical)10ROI: 363x8
12、7 pixelsL R T B = 1435 1797 1370 14560.80.60.40.200-60.80.60.40.2MTF50 = 0.324 Cy/Pxl=1585 LW/PH(RGB) = 0.325 0.323 0.325 Cy/P xlvaluation5ve ps2oC?= 1585 LW/pHUn dershar pening 17.1%MTF50 = 0.324 Cy/PxlPu rchase aMTF: Vertical w/NR0.2Edge an gle = 6.14 degsEstm. chart con trast = 48Selected EXIF da
13、taMTF20 = 0.479 Cy/PxlWTFmates=t0comNyquist f0.40.6Frequency, Cycles/pixelEdge p rofile: Vertical-40.8IMG 2250.JPG23-NOV-2014 17:45:12卜，I L . J mJ.?Imatest 4.0.15 Image SensorY-cha nnel (YBR11)Gamma = 0.50Edge 6.35 degsROI: 280x155 p ixels11% below -R of ctrLt, dk lvls = 212.1, 30.1 Lt/dk = 7.053264
14、 x 2448 p ixels (WxH)7.99 Mp xls10-90% rise = 1.66 pixels =1473 p er PHRGB rise = 1.66 1.66 1.66 p xlsRMS Edge rough ness = 0.0809 pxlsChart con trast = 10Gamma (from chart) = 0.848-20 2Pixels (Vertical)10ROI: 280x155 p ixelsL R T B = 1597 1876 1349 1503Undersharpening 18.0%MTF50 = 0.315 Cy/Pxlvalua
15、tionpersoCn= 1542 LW/pHMTF50 = 0.315 Cy/Pxl=1542 LW/PH(RGB) = 0.317 0.313 0.316 Cy/P xlEdge an gle = 6.35 degsEstm. chart con trast = 49.7Selected EXIF data0.2MTF20 = 0.476 Cy/Pxl wimOtetsboom0.40.6Freque ncy. Cycles/pixelNyquist fMTF: Vertical w/NR0.810 imat峦FIMG 2250.JPGNyquist fMTF: Horiz ontal w
16、/NR0.81a imdtestd-60.8Edge p rofile: Horiz ontal-423-NOV-2014 17:23:46Imatest 4.0.15 Image SensorIIIp-Y-cha nnel (YA22)Gamma = 0.50Edge -6.61 degs3264 x 2448 p ixels (WxH)7.99 Mp xls10-90% rise = 2.10 pixels=1168 per PHRGB rise = 2.21 2.11 1.84 pxlsRMS Edge rough ness = 0.0845 pxlsChart con trast =
17、10Gamma (from chart) = 0.743Lt, dk lvls = 217.3, 39.3 Lt/dk = 5.53-ROI: 169x294 pixels22% above ctr-2024Pixels (Horizo ntal)MTF50 = 0.266 Cy/Pxl=1304 LW/PH(RGB) = 0.264 0.266 0.277 Cy/P xl10)t mdrts0.6EvaluatM!TFf0V e0-26ftC/1 = 1304 LW/PH,Un dersharpe ning 24.6%MTF50 = 0.266 Cy/Pxl0.4c ，、丄MTF20 = 0
18、.421 Cy/Pxl-Purchaseat wwwFOrtatesLGom0.2Nyquist fMTF: Horiz ontal w/NR0.20.40.6Freque ncy. Cycles/pixel0.8IMG 2250.JPG23-Nov-2014 17:26:05ROI: 169x294 pixelsL R T B = 1533 1701 636 929Edge an gle = -6.61 degsEstm. chart con trast = 30.6Selected EXIF dataaenbrvel o 3 eodEEdge p rofile: Horiz ontalIm
19、atest 4.0.15 Image SensorIIIp-463264 x 2448 p ixels (WxH)7.99 Mp xlsY-channel (YA23)Gamma = 0.50Edge -6.6 degs10-90% rise = 2.21 pixels=1108 per PHRGB rise = 2.32 2.21 1.94 p xlsRMS Edge rough ness = 0.083 pxlsChart con trast = 10Gamma (from chart) = 0.752Lt, dk lvls = 217.2, 38.5 Lt/dk = 5.65-ROI:
20、126x418 pixels23% above ctr-2024Pixels (Horizo ntal)-610ROI: 126x418 pixelsL R T B = 1558 1683 537 9540.8MTF50 = 0.258 Cy/Pxl=1265 LW/PH(RGB) = 0.256 0.258 0.267 Cy/P xlEdge an gle = -6.6 degsEstm. chart con trast = 31.9Selected EXIF dataLtmvrfs0.60.4 EvaluatMonv 辭濒=1265 圖Undersharpening 25.6%MTF50
21、= 0.258 Cy/Pxlr . MTF20 = 0.407 Cy/PxlPu rchaseat wwwFonOesbcom0.2000.20.40.6Freque ncy. Cycles/pixelIMG 2250.JPGIhl I L - 一JEdge p rofile: Vertical23-Nov-2014 17:47:11Edge 5.91 degs7 3264 x 2448 p ixels (WxH)7.99 Mp xls_Y-cha nnel (YB15)Gamma = 0.50ROI: 216x117 pixels15% below ctr10-90% rise = 2.04
22、 p ixels =1202 p er PHRGB rise = 2.09 2.03 2.08 p xlsRMS Edge rough ness = 0.0779 pxlsChart con trast = 10Gamma (from chart) = 0.84Lt, dk lvls = 210.1, 30.4 Lt/dk = 6.91-6-4-20P ixels (Vertical)Imatest 4.0.15 Image Sensor t j g2Jr - :*H戶 J Q-I 亠JhhhIbv10ROI: 216x117 p ixelsL R T B = 1415 1630 1443 1
23、559XLtIMVRFS0.6ar / OKtlorp eaaE:;=7MTF50 = 0.254 Cy/Pxl=1244 LW/PH(RGB) = 0.252 0.252 0.268 Cy/P xlV EvaluatiOnF5Vers5OCT = 1244 LW/PHUn dersharpe ning 23.2%MTF50 = 0.254 Cy/P xlc .4 MTF20 = 0xlPu rchasat0.8 -Edge an gle = 5.91 degsEstm. chart con trast = 47.8Selected EXIF data0.4 r0.2 -Nyquist fMT
24、F: Vertical w/NR000.20.6Freque ncy. Cycles/pixelEdge p rofile: Vertical-40.40.8a irn/电 H JIMG 2250.JPG23-Nov-2014 仃:47:46Y-cha nnel (YB16)Gamma = 0.50Edge 6.34 degs3264 x 2448 p ixels (WxH)7.99 Mp xlsImatest 4.0.15 Image Se nsorROI: 259x121 pixels 16% below ctrLt, dk lvls = 210.6, 30 Lt/dk = 7.0310-
25、90% rise = 2.17 p ixels=1126 p er PHRGB rise = 2.23 2.17 2.15 p xlsRMS Edge rough ness = 0.089 pxlsChart con trast = 10Gamma (from chart) = 0.847-20 2Pixels (Vertical)I小 IM - 一J 沁強 卢占 右10ROI: 259x121 p ixelsL R T B = 1605 1863 1464 1584Evaluationverson=1151 LW/PHUn dersharpe ning 25.9%MTF50 = 0.235 Cy/Pxl=1151 LW/PH(RGB) = 0.233 0.234 0.246 Cy/P xl-Purcha4 o8 o6 o2 oMTF50 = 0.235 Cy/PxlMT.F20 = 0xlat wwwrHmaje0.20.40.6Freque ncy. Cycles/pixel0.8Edge an gle = 6.34 degsEstm. chart con trast = 49.4Selected EXIF dataNyquist fMTF: Vertical w/NR0