Physics/photography help

[notnek_01]

In these questions, I don't understand what answer I should put. Can anyone help me?

 

1) Each pixel that appears in a color picture is a combination of three prime colors. Specify these three colors, each of their bandwidth wave length, and if possible - outline the visible bandwidth.

 

I know the colours (red, green and blue) but I'm not sure what bandwidth wavlength and visible bandwidth means.

 

 

This is more a photography question so I hope someone can help:

 

2) Explain how different colors are represented in digital photography

[Klaynos]

You're in luck I'm an optical phycists (student) and a photgrapher

 

1) This will depend on the display device used, but for a general use if you investigate the colour detectors in your eye, they have a working bandwith (range of wavelengths they can detect) a good display device will have a central wavelength the same as this and it's band width will be no wider...

 

2) Well if you're going to display something with the 3colour pixel method, what information would you need to store at each pixel on your detector?

[notnek_01]

Thanks for the reply.

 

I've never learnt anything like this before so I might need a bit more help:

 

1) Where can I find the working bandwidth of the colour detectors in an eye?

 

2) Hue, saturation and brightness - am I correct?

[Klaynos]

1) http://health.howstuffworks.com/eye3.htm

 

2) Not really, it only records these indirectly. If you search around on how stuff works, you'll find a better explination than I can give here, but for each pixel (this is massively simplified) the detector records 3 values, one for each of the colours used on display units... These 3 do vary though depending on the standard of the file format used.

[notnek_01]

Thanks a lot. I think I understand it all now.

 

I have one more question but I wasn't going to ask it here because it is a science forum. But seeing as you study photography you might be able to help:

 

c) The first stage for reconstruction involves a registration process between two pictures. Suggest methods for pictures' registration (i.e., extracting similar elements in both pictures).

 

This is my last question, promise:-)

[Sataure]

2) Specifically is kind of technical. Usually each pixel has 3 8-bit values to represent the RGB value of that particular pixel, and often modern applications that use alpha channels have an 8-bit alpha value as well.

 

In programming they are often represented using hexi-decimal notation, i.e. 0xnnnnnnnn , where the each pair of n's (there are four) represent Alpha, Red, Green, and Blue respectively. White would be represented as 0xFFFFFFFF, and black as 0x00000000. A somewhat transparent magenta would be 0xAAFFFF00.

[Klaynos]

Thanks a lot. I think I understand it all now.

 

I have one more question but I wasn't going to ask it here because it is a science forum. But seeing as you study photography you might be able to help:

 

c) The first stage for reconstruction involves a registration process between two pictures. Suggest methods for pictures' registration (i.e., extracting similar elements in both pictures).

 

This is my last question, promise:-)

 

This is really a comp sci question, but I'd imagine they use pattern matching functions that raster accross key areas on the edges of the images...

 

My phone cam does it rather well...