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2.2 Content media

2.2.2 Digital mode: Image upscaling

 

To better understand what is meant by upscaling, it can be compared to compression. “Lossy” compression removes useful data from the image to reduce the total weight of the file. Upscaling matches the resolution of a given image to a higher display resolution by adding mathematically generated data. [1] Both phenomena have an effect on the authenticity and integrity of an image, because they change its original composition. Compression reduces the image quality without this loss necessarily being perceptible, while upscaling improves the image to give it the appearance of having a higher definition. Upscaling therefore represents a technological migration of the image to a new resolution.

In the case study for Nu•tka• by Stan Douglas, we found that upscaling had an impact on the spectator’s understanding of the work’s intended effect. The effect of Nu•tka• is based on an image of a given resolution. Upscaling clouds this effect by adding information to the image. It should, however, be noted that the intended effect is restored when upscaling is done using higher quality equipment, making it possible to present the work with an upscaled image. The exercise taught us, therefore, that upscaling carries a risk in particular situations where the visual effect of a work hinges on the specific resolution of the image.

If upscaling is conducted on a source image, it will no longer be possible to recuperate the image in its original state. It should be remembered that conservation practices recommend preserving material in its original state whenever possible.

In the coming years, the shift to high definition (HD) will no doubt lead to many visual documents being migrated to new formats. Upscaling is therefore an important issue that should be studied now in preparation for this eventuality.

With respect to conservation practices, it is recommended that upscaling be viewed as having a negative impact on the authenticity and integrity of a work..

 


[1] Upscaling increases the resolution of an image; to this end, it must create new data generated by a mathematical algorithm. Upscaling adds new pixels by mathematically manipulating the values of the surrounding pixels.