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Display Gaussian white noise for experiment

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  • Display Gaussian white noise for experiment


    I just got a uLCD43P and my project is to show white noise figures for several time steps (2D Gaussian distributed white noise in each step), with a different white noise in each step..

    I suppose generating such image might be hard for the microprocessor to do so, so I am thinking of generating the figures first by other softwares (eg, Matlab) and then present those figures on to the screen. Does that sound plausible? And more specifically

    1. What image type should I save the images in
    2. How to present a figure or several figures in sequence
    3. How to position the figure
    4. How to resize the figure (mapping pixels to the images)

    I am a rookie to this area and I know some posts might be there so appreciate it if some leads can be given to save the time searching blindly around.


  • #2
    What platform are you using?
    What sort of images are you talking about, can you show some examples?
    Are these images meant to be static, or do they change?
    There are scope type capabilities in ViSi Genie, Visi and Designer, that maybe your could use if you don't need rapid updates.
    If you are using image controls you just set a parameter within them to reposition them
    Resizing cannot be done on the fly, but for saved images, you can save a series of sizes
    The image format from the uSD is documented here in Q3
    Sorry I can't be more specific as I'm not sure exactly what you want to do.


    • #3
      Hi Mark

      I think I have solved most of the problems now, I generated the images and dragged them onto the screen in Visi.
      Now I have another issue, which is to sync the presentation of the images to triggers with a fixed frequency. (Microscope frame triggers).
      I have coded so that the microprocessor can get the trigger frequency (current frame trigger time in ms - previous frame trigger time in ms)/1000, but it feels like the number can only be integer (can 4D board handle float?), and the frequency is not always the same (I set it to be 20Hz on Arduino and the detected and print out frequency on 4D board is sometimes 20, 23, 26 etc). What causes the change of frequency?

      Lastly, can the presented images frequency be as fast as 100Hz if the size is about 100pixel x 100 pixel (i.e., if my microscopic imaging frame trigger is 100Hz, can the images on 4D screen be presented with that speed)? I think I saw once that it depends on the processing speed and the image size, is that right? (i.e. 1MHz processing would give max 100Hz for 100pixel x 100 pixel image).

      Attaching my images (moving bars instead of Gaussian white noise, but I think you get the idea) and the 4D system and Arduino codes in .txt (could you tell me what file type a programmer would like to receive for the codes also?).


      John Yang

      Attached Files


      • #4
        and sorry the Arduino code has 7.5Hz triggers, but I mean I tried several different frequencies and still got variable results as detected by 4D board