Multiple ROI Camera Mikrotron EoSens® 25CXP+ over CoaXPress with Marathon VCX-QP frame grabber

  • Hello,

    I am trying to use a Mikrotron 25+ CXP camera with 4 discrete ROIs of size 256 x 256, 10-bit. Unfortunately, there seems to be some overlap on the ROIs in microDisplay.

    Has anyone encountered such an issue before? Are there any existing VA designs for this problem?

    I am using the VCX-QP



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  • Hello Michael,

    microDisplay can only show one image, or one ROI, at a time. So I guess your Applet does the merging of the ROIs into one bigger image that you want to see in microDisplay.

    From the image Mroi5 I would say maybe a buffer run full in this process. So I would check if you have big enough buffer for the combining actions.

    If you have a VA File that you can share I can have a look and maybe give a better hint :)

    Best regards,


  • Hello Björn,

    Thank you. I will see if I can upload the file soon. I think it is a simple pass through, just like the example in C:\Program Files\SiliconSoftware\VisualApplets_3.1\Examples\Acquisition\BasicAcquisition\mE5-MA-VCX-QP\Area\ . My understanding is that the Multi ROI functionality is supposed to send the different ROIs as sequential frames.

    I will check the dimensions of the ImageBuffer.


  • Hello Michael,

    Sorry, but these operator was released by accident. Please do not use it. The operator is not yet fully functional. It was developed to support multiple streams, which so far is not supported by most cameras.

    If the camera sends the images sequentially you need to set the Applet parameters for one ROI and capture n pictures to get all ROIs. If you have some logic in your applet you could also merge them into one bigger image. In this case the size depends on the ROIs. That's why I asked for the applet you intend to use :)

    Best regards,


  • Hello Björn,

    Unfortunately I do not have access to the frame grabber, original design, or camera just yet, but I was wondering what you thought of this design



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    Edited once, last by MichaelCorreia: Small error in previous .va file; forgot to adjust bit width to 2 after Modulo4 ().

  • Hi Michael,

    I had a look at your example. Yes you could do that in this way, but I think it's to complicated if you do it like that.

    The intention behind this design is to get all ROIs into a different buffer. This would be possible just using 1 DMA. In your SDK-Program you just need to reserve 4 buffers at the end and you will get each ROI into a seperated buffer (

    You just need to run a sequence of 4 images in microDisplay than.

    If you want to combine the 4 ROIs into 1 image and want to show that at the same time in microDisplay than you need a more complexe applet.

    I added 2 versions here:

    1 one is simply appending all ROIs after each other (


    2. appends them in a Square(


    I hope that will give you a hint on how you could implement it for your need..

    best regards,


  • Thank you Björn,

    I appreciate your help. The square ROI seems quite complex compared to the AppendImage operator. Thank you for the very helpful designs.

    I will have the ability to check these on actual hardware soon; I will give an update once I know how well it performs.


  • Johannes Trein

    Changed the title of the thread from “Multiple ROI Camera over CXP with Marathon VCX-QP” to “Multiple ROI Camera Mikrotron EoSens® 25CXP+ over CoaXPress with Marathon VCX-QP frame grabber”.