Editing Cornell box (section)

=== Photographic images ===
Cornell University shared data that must be manually processed before being assembled into an image (e.g., through [[multispectral imaging]]). Few details are provided, except for the camera used, the implementation of seven narrow-band filters (to capture multiple wavelengths of the visible spectrum), and applied post-processing (noise reduction and lens correction). The captured wavelengths are briefly mentioned in the [[filename]]s, and seven different [[Monochrome|monochromatic]] sets are available. The specific configuration and capture time of the data are not listed, except for the reference to the data being taken 'in its current configuration' — which refers to the box's configuration at the time of capture, and is fairly self-explanatory. The data has been available on the website since at least 1998.

The 'final' processed image is not available for download, and no official or unofficial renditions have been released. To display it, the original data must first be interpreted and assembled. Because no examples are accessible online, an image was crafted specifically for this article and released on [[Wikimedia Commons]], along with some additional context.

Images found below were carefully recreated using available data, and they are '''for illustrative purposes only'''. Different methods and techniques can be used, leading to a variety of possible results. It is not difficult to notice that the compiled image (the result of digitally processed data) does not match the synthetic image reference<ref group="𝓲">Synthetic image reference provided by Cornell University discussed in [[Cornell box#Synthetic Image|Synthetic Image section]]</ref> (e.g., the tall block has a highly specular surface) or the scene data<ref group="𝓲">Reference scene data provided by Cornell University and discussed in [[Cornell box#Scene data|Scene data section]]</ref> (e.g., the camera position has been offset to reduce a distracting reflection on the tall block).

Seven monochromatic datasets were captured at different visible spectrum wavelengths. Using information obtained from the filenames, we can determine the captured wavelengths: 700&nbsp;nm, 650&nbsp;nm, 600&nbsp;nm, 550&nbsp;nm, 500&nbsp;nm, 450&nbsp;nm, and 400&nbsp;nm. These datasets can be combined to create [[RGB color model|red, green, and blue channels]], which are then used to produce a polychromatic image. One method to create these channels is by assigning the closest corresponding colors on the visible spectrum. The channels were assigned as follows:

* Red channel: 700&nbsp;nm, 650&nbsp;nm, 600&nbsp;nm
* Green channel: 550&nbsp;nm, 500&nbsp;nm
* Blue channel: 450&nbsp;nm, 400&nbsp;nm

Basic corrections were not applied, so no adjustments were made to [[Contrast (vision)|contrast]], [[Colorfulness|saturation]], [[Color balance|white balance]], etc. No advanced corrections (such as lens corrections for [[chromatic aberration]]) were performed. Minimal [[Tone mapping|tonemapping]] was applied, and no pixels were cropped. [[Defective pixel]]s and capture errors were retouched, but the unedited version is also available. The same principles apply to the synthetic renders, which were generated with a slightly offset camera, as the precise data for this particular shot is not provided. The camera was not properly calibrated and is only vaguely aligned with the short block.

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    | [[File:Cornell Box multispectral imaging.png|thumb|center|600px]]
    | Photographic image reference
    | [[File:Cornell Box multispectral imaging unedited.png|thumb|center|600px]]
    | Unedited version with the capture error visible near the edges of the image.
    | [[File:Cornell Box multispectral imaging extras.png|thumb|center|600px]]
    | Enhanced version with better visibility of construction elements, dust on the reflective surface, and caustics caused by surface irregularities and the sharp edges of the reflective tall block.
    | [[File:Cornell Box multispectral imaging enhanced.png |thumb|center|600px]]
    | Enhanced version with more pronounced defects like bloom, lens flare, chromatic aberration, misalignment between different wavelength captures etc.
    }}
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    | [[File:Cornell Box3 Octane (6K 8bit).png|thumb|center|600px]]
    | Example rendered with [[Octane Render]]
    | [[File:CornellBox OriginalCamera DistractingReflectionRed.png|thumb|center|600px]]
    | Example showing a distracting reflection when the original camera coordinates are used.
    | [[File:CornellBox OriginalCamera DistractingReflectionGreen.png|thumb|center|600px]]
    | Example showing weaker contrast when the original coordinates of the blocks and camera are used.
    }}
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