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Re: drawing an array of pixels to the screen
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Re: drawing an array of pixels to the screen


  • Subject: Re: drawing an array of pixels to the screen
  • From: John Stiles <email@hidden>
  • Date: Fri, 9 Nov 2007 20:56:33 -0800

+NSBitmapImageRep initWithBitmapDataPlanes:pixelsWide:pixelsHigh:bitsPerSample:samplesPerP ixel:hasAlpha:isPlanar:colorSpaceName:bitmapFormat:bytesPerRow:bitsPerPi xel: is pretty efficient. You're not copying the whole byte array, it just takes a reference to it.

However, another poster hit the nail on the head—if performance is important to you, might as well go OpenGL. You can't get any faster than that on OS X.

On Nov 9, 2007, at 7:27 PM, Jason Horn wrote:

I am working on a computer vision based app that detects objects in video images. I have to implement custom algorithms to locate and track objects, so I need to write code that has direct access to the pixel values and keep track of the x,y coordinates of certain objects. This is easiest to do with the image represented as a 2D array of int values. However, it seems that the only way to draw bitmaps to the screen is with NSImage and NSBitmapImageRep or CIImage. Is there another way? It seems like a waste (and a performance hit) to convert a 2D array of pixel values into a byte stream every time you want to display the image. Is there a way to draw the pixel values directly to the screen (and do it quickly).

Thanks for any ideas.
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 >drawing an array of pixels to the screen (From: Jason Horn <email@hidden>)

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