A&P I know this might be hard to explain but can you separate light frequencies in ps

Discussion in 'Lifestyle' started by Pineapple Devil, Feb 28, 2006.

  1. Pineapple Devil

    Pineapple Devil beat it!

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    like separate the low frequencies from the high frequencies that determine fine detail from broad lines
     
  2. natelam

    natelam New Member

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    Short answer: yes - a good example is Neatimage it allows you to alter different frequency ranges to correct noise degradation in images. Photoshop itself can do this, but the process is much more extended and requires some patience and a lot more skill with low and high pass filters.
     
  3. hash browns

    hash browns lolcathlon champion OT Supporter

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    :h5:
     
  4. Pineapple Devil

    Pineapple Devil beat it!

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    the reaso i ask is b/c in my Sensation and Perception class we are discussing the way the brain and eyes view low and high frequencies. i figured that since the book makes a lot of references to the similarities to photography and human's ability to see, i'd try to take a picture and separate, and possibly show them being stacked, the low and high frequencies to create a picture. maybe i'll get some extra credit for it

    something like...

    picture a: complete pictuer
    picture b: this is the low frequencies for picture a
    picture c: this is the high frequencies for picture a
     
  5. natelam

    natelam New Member

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    Are you a cognitive science major? Sounds like a class I took back in undergrad.

    In theory, your idea is a good one, temporal perception of visual stimuli is definately on a multilayer basis. However, with photography, frequency "stacking" is very simplistic - they simple add photons or in DSLR case, pixels, to a one dimensional canvas, being modified as more information is "percieved" by the sensor at different frequencies. The "algorithms" that the cerebral cortex uses to disseminate and organize the information from the retina and optic nerve (which then travels through the lateral geniculate nucleus into the optic centers of the brain) are much more complicated, you need to take into account the 2-D and light flicker information amongst a ton of other things that the brain processes (in theory) to create the image. Most importantly, if you care to read enough of the visual perception research, the final image that you visualize, is a very complex combination of information from the retina and information that the brain "creates" or fills in based on predictions and experience - hence the basis for optical illusions and such.

    There are a ton of cog scientists working with engineers to create robotic eyes that simulate these kinds of complexities, but no one has gotten close. Really interesting to read up on since you are into photography.
     
  6. hash browns

    hash browns lolcathlon champion OT Supporter

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    you could also do this in matlab by saving your image as a tiff then processing it by running a lowpass and highpass filter over the image

    if you want to get tricky you can do this for only certain color channels or wavelengths and be all :cool:
     
  7. Pineapple Devil

    Pineapple Devil beat it!

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    double major with nursing and psychology. the sensation and perception class and a cognitive psychology class i'm taking are kind of backing each other. some of the stuff we touch on in cognitive is studied in depth in the sensation and perception class
     
  8. CRC

    CRC New Member

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    i need examples this is too confusing :hsugh:
     
  9. natelam

    natelam New Member

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    I loathe Matlab. My senior thesis project was a neural network program in Matlab based on visual perception and categorization. After about 180 hours of coding, I got an A for effort, and a C for complete and utter confusion.
     
  10. hash browns

    hash browns lolcathlon champion OT Supporter

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    You can do this with a basic image processor/compression model, such as Jpeg and change the quantization coefficients in the Quantization phase to be heavily biased in favor of compression, this will begin to wipe out the high frequency data. Then you could do an image subtraction of the low frequency parts from the original to show what high frequency components are getting wiped out.
     
  11. El Chupacabras

    El Chupacabras Blue and Gold Member

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    Natelam, I dont mean to get too personal, but what do you do? (job) It's interesting to listen to some of your responses :o
     
  12. natelam

    natelam New Member

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    You'll never guess...:) It has nothing to do with cameras or computers, but I'm working hard to create a niche for my expertise in my current field.
     
  13. El Chupacabras

    El Chupacabras Blue and Gold Member

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    Slow down, the details are too intense :p But if you were just trying to get me to actually guess what it is you do, I wont even try :)
     
  14. natelam

    natelam New Member

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    =) Edited now that the question has been answered.
     
    Last edited: Mar 1, 2006
  15. El Chupacabras

    El Chupacabras Blue and Gold Member

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    Pretty epic plans. I wish you the best of luck with it all. :bigthumb:

    Anyway, back to light frequencies in PS :squint:
     
  16. Pineapple Devil

    Pineapple Devil beat it!

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    i'm thinking i can do a pseudo-high frequency picture by using the unsharpen mask to extreme. that way it will outline all of the lines in the picture and can represent the highest frequency. i'll try it in a minute
     
  17. please post example shots of wtf this thread is about :dunno:
     

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