This example demonstrates how to use a running average to remove transients from captured images.
1. Set up an acquisition and create a storage buffer, a working buffer for the current image, and a repository for the running average. The running average is a 16-bit buffer to allow for up to 256 8-bit images to be averaged together.
2. Create an array of buffers to hold each of the images being averaged. This array works as a shift register to subtact the oldest image (step 4) and add the newest image (step 6)
3. The calculation determines which index of the array to access. This index is then indexed for use in this iteration of the loop.
4. For each iteration, first subtract the oldest image from the repository. You cannot subtract images that have not been stored, so subtracting occurs on the second iteration of the loop.
5. The newly acquired image is converted to a 16-bit image and stored in the current index of the array.
6. Add the current index to the repository and display the image. 16-bit images are dynamically ranged when displayed so that the image displayed is the average of all images added to the repository. Steps 4, 5, and 6 repeat, subtracting the oldest image and adding the newest image to create a running average.
7. 16-bit images are signed. This step subtracts 2^15 from the repository the first time through the loop and allows access to the entire 16-bits of resolution.
8. This step scales the histograms so that the histogram for 16-bit (average) and 8-bit (current) images cover the same range.
9. Dispose of the buffers and WindDraw windows.
10. This loop calculates the frames per second being handled. Notice the use of notifiers to end this while loop when the main loop ends.
NOTE: You must have IMAQ Vision installed to run this example. The maximum number of buffers used should be no greater than 255 for 8 bit images.
