Cornell Box Cornell Box Data
Cornell University Program of Computer Graphics 		Cornell Seal

Photographic Images

We have made high-quality pictures of the Cornell box in its current configuration. The liquid-cooled Photometrics PXL1300L CCD camera has a precision of 12 bits. We used 7 narrow-band filters to get a coarse sampling across the visible spectrum. Dark current has been subtracted from the images, and flat-field correction has been applied to account for the cosine fall-off and the lens fall-off. The following data are available:
  • IPLab images The images are collected in a compressed tar file (10 MB compressed, 18 MB uncompressed!). They are in IPLab format, which can be read using a simple Matlab function iplab_read.
  • TIFF images The images are available in TIFF files, with 16 bits per pixel. This format can be read by a number of applications, including Photoshop. There is a choice of either a compressed tar archive (about 10MB compressed, 18MB uncompressed) or a ZIP archive (about 10MB).
  • OpenEXR images The images are also available in the OpenEXR high-dynamic-range image format. Each pixel is represented as a 15-bit floating-point number with a 10-bit mantissa and 5-bit exponent. There is a choice of either an uncompressed tar archive (about 8MB, gzip compression shrinks it by only 0.4%) or a ZIP archive (about 8MB).
  • Transmission spectra of the 7 corresponding filters, the lens system, and the response spectrum of the camera are available from our page with measurement data.

Synthetic Images

A synthetic image file, generated from the data below, is available in two formats:

Scene Data

The reflectance data and the geometric data for the Cornell Box (with diffuse objects) are presented below. The data are also available in two other formats:
  • As an mdla file. MDLA is a format defined at Cornell for scene descriptions, with specifications that are easily extendible.
  • As an Inventor file. The RGB reflectance values in this file are for previewing purposes only; they do not correspond to the real spectral data.

1. Camera parameters

Position 278 273 -800
Direction 0 0 1
Up direction 0 1 0
Focal length 0.035
Width, height 0.025 0.025

2. Surface reflectances

Surfaces are assumed to be Lambertian. The reflectance spectra have been measured at discrete wavelengths (in nm).
Wavelengthwhitegreenred
4000.3430.0920.040
4040.4450.0960.046
4080.5510.0980.048
4120.6240.0970.053
4160.6650.0980.049
4200.6870.0950.050
4240.7080.0950.053
4280.7230.0970.055
4320.7150.0950.057
4360.7100.0940.056
4400.7450.0970.059
4440.7580.0980.057
4480.7390.0960.061
4520.7670.1010.061
4560.7770.1030.060
4600.7650.1040.062
4640.7510.1070.062
4680.7450.1090.062
4720.7480.1120.061
4760.7290.1150.062
4800.7450.1250.060
4840.7570.1400.059
4880.7530.1600.057
4920.7500.1870.058
4960.7460.2290.058
5000.7470.2850.058
5040.7350.3430.056
5080.7320.3900.055
5120.7390.4350.056
5160.7340.4640.059
5200.7250.4720.057
5240.7210.4760.055
5280.7330.4810.059
5320.7250.4620.059
5360.7320.4470.058
5400.7430.4410.059
5440.7440.4260.061
5480.7480.4060.061
5520.7280.3730.063
5560.7160.3470.063
5600.7330.3370.067
5640.7260.3140.068
5680.7130.2850.072
5720.7400.2770.080
5760.7540.2660.090
5800.7640.2500.099
5840.7520.2300.124
5880.7360.2070.154
5920.7340.1860.192
5960.7410.1710.255
6000.7400.1600.287
6040.7320.1480.349
6080.7450.1410.402
6120.7550.1360.443
6160.7510.1300.487
6200.7440.1260.513
6240.7310.1230.558
6280.7330.1210.584
6320.7440.1220.620
6360.7310.1190.606
6400.7120.1140.609
6440.7080.1150.651
6480.7290.1170.612
6520.7300.1170.610
6560.7270.1180.650
6600.7070.1200.638
6640.7030.1220.627
6680.7290.1280.620
6720.7500.1320.630
6760.7600.1390.628
6800.7510.1440.642
6840.7390.1460.639
6880.7240.1500.657
6920.7300.1520.639
6960.7400.1570.635
7000.7370.1590.642

3. Light source properties

The light source is approximated as having a constant reflectance of 0.78, and the following emission spectrum:
Wavelengthlight
400.0 0.0
500.0 8.0
600.0 15.6
700.0 18.4

4. Surface Geometry

The geometry has been measured from the physical Cornell Box. The surfaces are therefore not perfectly perpendicular. All surfaces are quadrilaterals. They are specified below by their vertices.
Floor
white
552.8 0.0   0.0   
  0.0 0.0   0.0
  0.0 0.0 559.2
549.6 0.0 559.2
Holes (for disc. mesh)
130.0 0.0  65.0
 82.0 0.0 225.0
240.0 0.0 272.0
290.0 0.0 114.0

423.0 0.0 247.0
265.0 0.0 296.0
314.0 0.0 456.0
472.0 0.0 406.0

Light
light
343.0 548.8 227.0 
343.0 548.8 332.0
213.0 548.8 332.0
213.0 548.8 227.0

Ceiling
white
556.0 548.8 0.0   
556.0 548.8 559.2
  0.0 548.8 559.2
  0.0 548.8   0.0
Hole (for disc. mesh)
343.0 548.8 227.0
343.0 548.8 332.0
213.0 548.8 332.0
213.0 548.8 227.0

Back wall
white
549.6   0.0 559.2 
  0.0   0.0 559.2
  0.0 548.8 559.2
556.0 548.8 559.2

Right wall
green
0.0   0.0 559.2   
0.0   0.0   0.0
0.0 548.8   0.0
0.0 548.8 559.2

Left wall
red
552.8   0.0   0.0 
549.6   0.0 559.2
556.0 548.8 559.2
556.0 548.8   0.0

Short block
white
130.0 165.0  65.0 
 82.0 165.0 225.0
240.0 165.0 272.0
290.0 165.0 114.0

290.0   0.0 114.0
290.0 165.0 114.0
240.0 165.0 272.0
240.0   0.0 272.0

130.0   0.0  65.0
130.0 165.0  65.0
290.0 165.0 114.0
290.0   0.0 114.0

 82.0   0.0 225.0
 82.0 165.0 225.0
130.0 165.0  65.0
130.0   0.0  65.0

240.0   0.0 272.0
240.0 165.0 272.0
 82.0 165.0 225.0
 82.0   0.0 225.0

Tall block
white
423.0 330.0 247.0
265.0 330.0 296.0
314.0 330.0 456.0
472.0 330.0 406.0

423.0   0.0 247.0
423.0 330.0 247.0
472.0 330.0 406.0
472.0   0.0 406.0

472.0   0.0 406.0
472.0 330.0 406.0
314.0 330.0 456.0
314.0   0.0 456.0

314.0   0.0 456.0
314.0 330.0 456.0
265.0 330.0 296.0
265.0   0.0 296.0

265.0   0.0 296.0
265.0 330.0 296.0
423.0 330.0 247.0
423.0   0.0 247.0

Last updated 02/02/05 PCG www Home