IMX8 ISP operating only on ROI

[federico_rachelli]

Hi.

We are facing some problems about the ISP service in our IMX8 products.

We should be able to make ISP work only on a determined ROI of the picture coming from MIPI.
In fact, now we can only use ISP on the whole image coming from ISP.

As an example, in our case we have an image of size 1120x1376, but the last 16 rows are embedded data that we cannot send in another VC. The ISP should work on the picture (1120x1360) and not on the embedded data (that are always in the bottom of the picture).

Is it possible to do this?

Thanks in advance!
Have a nice day.
Federico Rachelli, Datalogic S.r.l.

[Manuel_Salas]

Hello @federico_rachelli 

Hope you are doing very well.

We have not an example of this, but it makes me think you can do it at driver level.

For example, the ACQ module uses the bounds_width and bounds_height parameters to understand the raw MIPI payload dimensions, and then uses top, left, width, and height to extract the effective Region of Interest (ROI).

You can see that information in the i.MX 8M Plus Camera and Display Guide.

To discard the 16 rows of embedded data at the bottom of your 1120x1376 frame, you need to set the .size property in your sensor's ISP driver configuration:

.size = {
    .bounds_width  = 1120,
    .bounds_height = 1376,  /* Total MIPI payload including embedded data */
    .top           = 0,
    .left          = 0,
    .width         = 1120,  
    .height        = 1360,  /* Effective image height (1376 - 16) */
},

Take a look to the chapter 4.1.2 Sensor size configuration in driver of the document mentioned above.

Best regards,

Salas.