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Thread: Pixels

  1. #1
    Join Date
    Mar 2009
    Qt products
    Unix/X11 Windows

    Default Pixels

    I have two questions?
    1-Is the quality of a picture related to its number of pixels?(I know its not related to c++ and Qt)
    2-Is it possible to work with individual pixels of a picture via Qt?
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  2. #2
    Join Date
    Jan 2008
    Thanked 140 Times in 132 Posts
    Qt products
    Qt4 Qt5
    Unix/X11 Windows

    Default Re: Pixels

    1. More pixels equals more precise mapping from real world to discrete computer image - so it's better quality in that way. But color of every pixel is also stored as a discrete value and is important thing if we are talking about quality. You can have bilions of pixels in one image, but quality would be poor if you use 1bit color ber pixel - there will be only black or white pixels, which is not always good... Usual it's 8 bit for every color: Red, Green, Blue whatgives you 256^3 = 16777216 colors (plus 8bit alpha). And of course I'm talking about uncompressed images (JPEG images are compressed with a loss in quality so they are not good for image processing).
    2. Take a look at a QImage - I thinks it's what you need.
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