I want to use PCI 1407 and a square pixel CCD camera to capture and count moving Interference Fringes to get phase and displacement information what will be best fatest option

[AjayShankar]

I have to use grating Interferometer Fringes (linear black and white bands) to get displacement information in my encder development project. I am using IMAQ device from NI PCI 1407 and a CCD camera with sony chip ICX249. I want to get 4 channel output from this CCD by adding every 4th pixel starting from 1st 2nd 3rd and 4th pixel which will give me 90 degree shifted 4 phase quadrature signal.I am a starter please help me to best utilise the NI plateform for fastest possible fringe motion counting

[Yusuf C]

Hello,

Once you capture your image use the IMAQ ImageToArray function to convert your image into a 2D array. You can utilize for loops and array functions to extract every 4th pixel starting from different offsets and store them into smaller 2D arrays. You can convert these sub-arrays back to an image using the IMAQ ArrayToImage function.
Hope this helps. Let me know if you have further questions regarding this.

Regards,

Yusuf C.
Applications Engineering
National Instruments

[AjayShankar]

Hello Yusuf,
Thanks for answer ,I am concerned with the speed of data collection. If I am using IMAQ features and all those pixels comes into data them my online processing to get data displacement at least every millisecond becomes difficult. How can I use only few set of arrays as 4 phase shifted data aquisition channel effectively giving four phase shifted signal which can be used for phase retrieval and phase unwrapping using suitable algorithms. By IMAQ techniques taking full frame immage into consideration it becomes two slow to be used in a encoder processing. I intend to use CCD so that prior to get data from the Fringe pattern and its movement I would like to even get some information of fringe shape otherwise a linear array CCD or Photodiode coul
d have done these measurement Once shape is determined I want to use this CCD as simple signal collecting device.So my problem is to use only few of the pixels output as useful output which will generate 4 phase shifted signal for me and suppress all other pixels so that processing becomes fast.
Is it possible with only these IMAQ devices or seperate signal conditionong device will be required.I want to use some of the fixed pixels output from a moving image as signal input to get phase/displacement data for encoders. You know even for an speed of target scale movement of .1meter/second if I am targeting 1 microm accuracy I would like to gather information of those pixels out put every 10 microsecond which is too much for general processing in IMAQ