We looked at some more at the RGB colour system. Then we examined the Lab colour system and saw how subsampling the colour comment of an image was not as noticeable as subsampling the luminance component.
We looked at the CMYK system used in printing.
[Recoding failed]
I spoke a bit about image compression. I explained image subsampling and interpolation.
We began to look at pixel depth reduction when my laptop failed. We will pick up again from this point in the next class.
We looked at digitising black & white images and considered the impact the sample rate (dpi) and number of quantisation level (bit per pixel) have on the quality.
When an image is subsampled the missing pixels have to be accounted for by the receiver. This can be accomplished by increasing the size of the pixels that are present, or by interpolating the missing pixels. The different is illustrated in these images. You need to click on them to see them at full size.
We looked at Digitisation and saw how both the number of quantization levels and the sample rate can affect the fidelity of the digital representation of the analogue values.