Aliasing in Photography

Aliasing is known error in the field of signal analysis caused by insufficient sampling rate. In image processing aliasing of images take place too. This article, Aliasing in Photography has more closer relationship with Physics than Photography itself, however, we have tried to keep this article on Aliasing in Photography as simple and understandable by anyone.

 

What is Aliasing and its role in Digital Photography

 

In the signal processing aliasing occurs when we try digitizing the analog signals. As in case of Digital Photography, the photons are to be captured by a digital image sensor and later to be processed by the in house image processor built within the digital camera, Aliasing also appears in case of Digital Photography. In digital image processing and computer graphics,  appearance of moire patterns can be a good example of aliasing.

 

There are various mathematical formula exists to represent the physics of Aliasing in graphical way, we however is carefully avoiding this part in our text.

 

 

Ways to reduce or correct the errors of Aliasing in Photography

 

The practical way how Aliasing in Photography appears can be explained quite easily – the edges of a smooth object often appears as if composed of line composed of saw tooth. In various photo editing softwares, including Adobe Photoshop Anti Aliasing to give such images a smoother look is often practiced and usually it is quite laborious and multi step process.

As everything in this physical World works within a limit, i.e. the Aliasing effects and artifacts added in the captured image by a cheap low cost digital camera or by an integrated camera of Mobile Phones, where often a separate dedicated image processor is not used, Aliasing is often found along with noise and other artifacts.

It is enough to say, it is not possible to correct or rather the needed labor and time needed for fixing Aliasing in the above cases are quite meaningless.