Intensity line scan

Hello. I want measure intensity profile. I have linear camera (Teledyne Dalsa Linea 8k) so output of scan should be 1x~8000 array but it is 8192x1024. Of course there is option to change size of output image but minimal parameter is 2. Is there any function that allows you to get a profile of intensity (1D array) ?

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Hi there,

and sorry for the delayed response. I had a long weekend :).

It sounds that you are using the GigE version of the Linea camera. Using a GigE camera you should know that there are some technical reasons why it is not advisable to set a low image height in linescan cameras. The linescan image is transferred in network packets in a specific size and each image is leaded and trailed with mandatory packets with information about the image itself (image number, size…). Those leader and trailer do not contain any pixel information and are therefore a so called overhead. By decreasing the image height you will increase the network overhead as more and more of those leaders and trailers will have to be send each second.

If your linerate is not as high as I think it is a small image height is of course possible. Then you could think about using the CVB method “CreateImageMap” to crop the needed line of each image. The advantage of this method is that the pixel wil not be copied and therefore the croping will be very fast.

Can you tell me which programming language you are using? Why is it not possible to use higher images (like 1000 lines) and calculate the intensity porfile for each line afterwards?

best regards,
Theo

Currently I using Matlab and Python and I evaluate where it will be easier to write a program. I will present a few details about my use. I want measure laser beam intensity profile. I will put linear camera to motorized stage and scan profile line by line to create 2D intensity map. Motorized stage step is not fast so I dont need high speed (line scan -> step -> line scan …). I see two options:

  1. Scan line -> send to computer -> motion step -> line scan …
  2. Scan line -> step -> scan line ->… -> create image -> send image

Normally the result of a linescan acquisition is the same as you have it with area scan cameras. So as I understand this would be your option 2. E.g. if your stage would have 5000 steps you would acquire 5000 lines in one 2D image. Afterwards you can split this image into lines for further processing if you want.

However there are some reasons to go for option 1. E.g. if you would like to react on your results as fast as possible while the stage is still moving. If you have a good reason for option 1 you would have to find a good compromise between linerate and image height. With GigE cameras normally an image height like 10 or 100 lines is selected but as said before this depends on your linerate itself.

If there are no reasons for option 1 I definitely would suggest option 2.

If you have more questions regarding linescan cameras which are not completely regarding CVB I will send you a PN so that we can discuss it a bit more personally.

best regards,
Theo

I think I do not have the rights for PN, yet. Please write an email to support@stemmer-imaging.de with a link to this topic. I will answer on this e-mail.

best regards,
Theo