Quantizing and Noise in Digital Phtography - New technical article

In a digital camera, when we take the voltage output of an individual sensor element and convert it to digital form, a phenomenon called quantizing (often called quantization) takes place. As a result, the digital representation does not exactly represent the voltage. At the end of the digital image chain, this results in a discrepancy between the reconstructed image and the original image.

In the area of waveform based digital representation of speech waveforms, we sometimes characterize this discrepancy between the original data and the reconstructed data as a special kind of pseudo-noise, quantizing noise.

Some workers suggest that this concept is pertinent to the impact of quantizing error on digital images, and that quantizing noise should be reckoned among the ingredients of noise in a digital imaging system, a notion with which I disagree.

In any case, the process of quantizing does have an effect on how noise already present in the sensor voltage is seen in the digital representation.

I have just released to my technical information site, The Pumpkin, a new technical article, "Quantizing and Noise in Digital Photography", available here:

http://doug.kerr.home.att.net/pumpkin/index.htm#Quantizing_Noise

It discusses both these matters in considerable detail.