Posts by DarkEnergy 3 publicly visible posts • joined 20 May 2011
My car HUD displays actual speed, maximum local road speed, navigation indications and a flashing red car if I drive too close to the car in front.
My conclusion: HUD it is the best safety accessory a car can have.
I agree with previous postings in that projecting information not related to the actual driving can be distractive. I would be very worried about incorporating in a HUD email, phone or twitter information.
The resolution of a 1920*1080 picture is less than its number of pixels. This is what I was trying to describe in my previous post.
A 1920*1080 picture can only resolve 1920/K * 1080/K regularly distributed elements where K is larger than 2.3 according to the Nyquist theorem.
Just do the experiment of taking an image of 1920*1080 regularly spaced holes in a back illuminated plate.
Because the number of bright spots is the same as the number of pixels, the light from each hole will fill each and every of the available pixels and the resulting image will be completely uniform, no structure will be detectable. To RESOLVE a such a distribution of holes you need black pixels between the white pixels to detect the black spaces between the holes in the plate. i.e. twice as many pixels.
Conclusion to resolve a 1920*1080 distribution or image you need a display of at least 3960*2160 pixels.
Sampling is not the same as resolution!
A common mistake is to confuse resolution with sampling. To reproduce the RESOLUTION of a normal eye (~1 arc minute) with a digital display device what is needed is slightly more than 2 pixels per resolution element according to the Nyquist–Shannon sampling theorem and not 1 pixel per resolution element.
In other words, you do not want to resolve the screen and see each screen pixel. What you need is to match the screen resolution to the eye resolution. The theoretical maximum screen resolution of ANY digital screen is given by the number of pixels divided by the Nyquist factor. In the case of HD would be 1920/2.3=830 in the horizontal direction. This is the resolution you need to match to the eye resolution of 1 arc minute. The eresulting distances to the TV screen are therefore 2.3 times larger than the ones you quote,
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