function [x_1931, y_1931, z_1931, x_1964, y_1964, z_1964, lambdai] = CIE_standard_observer( lambdai ) % Usage: % [x_1931, y_1931, z_1931, x_1964, y_1964, z_1964, lambdai] = CIE_standard_observer( lambdai ) % lambdai (optional) specifies the wavelengths (in nm) at which the spectra is desired % lambdai should be between 360nm and 830nm % Author: Kristian Kirk % Last modified: 9 Aug 2004 % Source: http://www.cis.rit.edu/mcsl/online/cie.shtml tmp = [ 360 0.0001299 0.000003917 0.0006061 360 1.222E-07 1.3398E-08 5.35027E-07 365 0.0002321 0.000006965 0.001086 365 9.1927E-07 1.0065E-07 4.0283E-06 370 0.0004149 0.00001239 0.001946 370 5.9586E-06 6.511E-07 2.61437E-05 375 0.0007416 0.00002202 0.003486 375 0.000033266 0.000003625 0.00014622 380 0.001368 0.000039 0.006450001 380 0.000159952 0.000017364 0.000704776 385 0.002236 0.000064 0.01054999 385 0.00066244 0.00007156 0.0029278 390 0.004243 0.00012 0.02005001 390 0.0023616 0.0002534 0.0104822 395 0.00765 0.000217 0.03621 395 0.0072423 0.0007685 0.032344 400 0.01431 0.000396 0.06785001 400 0.0191097 0.0020044 0.0860109 405 0.02319 0.00064 0.1102 405 0.0434 0.004509 0.19712 410 0.04351 0.00121 0.2074 410 0.084736 0.008756 0.389366 415 0.07763 0.00218 0.3713 415 0.140638 0.014456 0.65676 420 0.13438 0.004 0.6456 420 0.204492 0.021391 0.972542 425 0.21477 0.0073 1.0390501 425 0.264737 0.029497 1.2825 430 0.2839 0.0116 1.3856 430 0.314679 0.038676 1.55348 435 0.3285 0.01684 1.62296 435 0.357719 0.049602 1.7985 440 0.34828 0.023 1.74706 440 0.383734 0.062077 1.96728 445 0.34806 0.0298 1.7826 445 0.386726 0.074704 2.0273 450 0.3362 0.038 1.77211 450 0.370702 0.089456 1.9948 455 0.3187 0.048 1.7441 455 0.342957 0.106256 1.9007 460 0.2908 0.06 1.6692 460 0.302273 0.128201 1.74537 465 0.2511 0.0739 1.5281 465 0.254085 0.152761 1.5549 470 0.19536 0.09098 1.28764 470 0.195618 0.18519 1.31756 475 0.1421 0.1126 1.0419 475 0.132349 0.21994 1.0302 480 0.09564 0.13902 0.8129501 480 0.080507 0.253589 0.772125 485 0.05795001 0.1693 0.6162 485 0.041072 0.297665 0.5706 490 0.03201 0.20802 0.46518 490 0.016172 0.339133 0.415254 495 0.0147 0.2586 0.3533 495 0.005132 0.395379 0.302356 500 0.0049 0.323 0.272 500 0.003816 0.460777 0.218502 505 0.0024 0.4073 0.2123 505 0.015444 0.53136 0.159249 510 0.0093 0.503 0.1582 510 0.037465 0.606741 0.112044 515 0.0291 0.6082 0.1117 515 0.071358 0.68566 0.082248 520 0.06327 0.71 0.07824999 520 0.117749 0.761757 0.060709 525 0.1096 0.7932 0.05725001 525 0.172953 0.82333 0.04305 530 0.1655 0.862 0.04216 530 0.236491 0.875211 0.030451 535 0.2257499 0.9148501 0.02984 535 0.304213 0.92381 0.020584 540 0.2904 0.954 0.0203 540 0.376772 0.961988 0.013676 545 0.3597 0.9803 0.0134 545 0.451584 0.9822 0.007918 550 0.4334499 0.9949501 0.008749999 550 0.529826 0.991761 0.003988 555 0.5120501 1 0.005749999 555 0.616053 0.99911 0.001091 560 0.5945 0.995 0.0039 560 0.705224 0.99734 0 565 0.6784 0.9786 0.002749999 565 0.793832 0.98238 0 570 0.7621 0.952 0.0021 570 0.878655 0.955552 0 575 0.8425 0.9154 0.0018 575 0.951162 0.915175 0 580 0.9163 0.87 0.001650001 580 1.01416 0.868934 0 585 0.9786 0.8163 0.0014 585 1.0743 0.825623 0 590 1.0263 0.757 0.0011 590 1.11852 0.777405 0 595 1.0567 0.6949 0.001 595 1.1343 0.720353 0 600 1.0622 0.631 0.0008 600 1.12399 0.658341 0 605 1.0456 0.5668 0.0006 605 1.0891 0.593878 0 610 1.0026 0.503 0.00034 610 1.03048 0.527963 0 615 0.9384 0.4412 0.00024 615 0.95074 0.461834 0 620 0.8544499 0.381 0.00019 620 0.856297 0.398057 0 625 0.7514 0.321 0.0001 625 0.75493 0.339554 0 630 0.6424 0.265 5E-05 630 0.647467 0.283493 0 635 0.5419 0.217 0.00003 635 0.53511 0.228254 0 640 0.4479 0.175 0.00002 640 0.431567 0.179828 0 645 0.3608 0.1382 0.00001 645 0.34369 0.140211 0 650 0.2835 0.107 0 650 0.268329 0.107633 0 655 0.2187 0.0816 0 655 0.2043 0.081187 0 660 0.1649 0.061 0 660 0.152568 0.060281 0 665 0.1212 0.04458 0 665 0.11221 0.044096 0 670 0.0874 0.032 0 670 0.0812606 0.0318004 0 675 0.0636 0.0232 0 675 0.05793 0.0226017 0 680 0.04677 0.017 0 680 0.0408508 0.0159051 0 685 0.0329 0.01192 0 685 0.028623 0.0111303 0 690 0.0227 0.00821 0 690 0.0199413 0.0077488 0 695 0.01584 0.005723 0 695 0.013842 0.0053751 0 700 0.01135916 0.004102 0 700 0.00957688 0.00371774 0 705 0.008110916 0.002929 0 705 0.0066052 0.00256456 0 710 0.005790346 0.002091 0 710 0.00455263 0.00176847 0 715 0.004106457 0.001484 0 715 0.0031447 0.00122239 0 720 0.002899327 0.001047 0 720 0.00217496 0.00084619 0 725 0.00204919 0.00074 0 725 0.0015057 0.00058644 0 730 0.001439971 0.00052 0 730 0.00104476 0.00040741 0 735 0.000999949 0.0003611 0 735 0.00072745 0.000284041 0 740 0.000690079 0.0002492 0 740 0.000508258 0.00019873 0 745 0.000476021 0.0001719 0 745 0.00035638 0.00013955 0 750 0.000332301 0.00012 0 750 0.000250969 0.000098428 0 755 0.000234826 0.0000848 0 755 0.00017773 0.000069819 0 760 0.000166151 0.00006 0 760 0.00012639 0.000049737 0 765 0.000117413 0.0000424 0 765 0.000090151 3.55405E-05 0 770 8.30753E-05 0.00003 0 770 6.45258E-05 0.000025486 0 775 5.87065E-05 0.0000212 0 775 0.000046339 1.83384E-05 0 780 4.15099E-05 0.00001499 0 780 3.34117E-05 0.000013249 0 785 2.93533E-05 0.0000106 0 785 0.000024209 9.6196E-06 0 790 2.06738E-05 7.4657E-06 0 790 1.76115E-05 7.0128E-06 0 795 1.45598E-05 5.2578E-06 0 795 0.000012855 5.1298E-06 0 800 1.0254E-05 3.7029E-06 0 800 9.41363E-06 3.76473E-06 0 805 7.22146E-06 2.6078E-06 0 805 0.000006913 2.77081E-06 0 810 5.08587E-06 1.8366E-06 0 810 5.09347E-06 2.04613E-06 0 815 3.58165E-06 1.2934E-06 0 815 3.7671E-06 1.51677E-06 0 820 2.52253E-06 9.1093E-07 0 820 2.79531E-06 1.12809E-06 0 825 1.77651E-06 6.4153E-07 0 825 0.000002082 8.4216E-07 0 830 1.25114E-06 4.5181E-07 0 830 1.55314E-06 6.297E-07 0 ]; lambda = tmp(:,1); if nargin < 1 lambdai = lambda; end x_1931 = interp1( lambda, tmp(:,2), lambdai, 'linear' ); y_1931 = interp1( lambda, tmp(:,3), lambdai, 'linear' ); z_1931 = interp1( lambda, tmp(:,4), lambdai, 'linear' ); x_1964 = interp1( lambda, tmp(:,6), lambdai, 'linear' ); y_1964 = interp1( lambda, tmp(:,7), lambdai, 'linear' ); z_1964 = interp1( lambda, tmp(:,8), lambdai, 'linear' );