FPGA Image Convolution error

[prabhakaran]

Hi,

 

 

I am trying to use image convolution inside FPGA. My Image size is around 6kx2k. The convolution is applied properly until 2600 pixels in x resolution. After that, the values seem to miss previous row data. 

 

In Detail: As convolution is matrix operation, image data needs to be stored for the operation. But it seems there is an inadvertent error storing only 2600 pixels per row inside FPGA. And hence the filtered output is calculated assuming these pixels to be 0. 

 

I have tried with different image sizes, different convolution kernels, and also in different targets (cRIO 9030 and IC 3173). All results are same.

 

I have attached a screenshot of FPGA VI and an example image.

 

The example image shows an input image of 4000x2500 of same pixel value 16.The kernel is 3x3 of values 1 with divider=1. The RT image is processed using IMAQ convolute inside RT controller and has value 144 [(9*16)/1] for all pixels. But the FPGA processed image (zoomed in) has 144 until 2597 pixels and then 112 (7*16- showing 1 column of 2 rows missing) at 2598, 80 (5*16- showing 2 columns of 2 rows missing) at 2599 and 48 after that (missing 3 columns of 2 rows- current row is always present). This shows the data is missing from the previous rows after 2600 index.

 

Is there some mistake in the code or any workaround available?

Edited December 19, 2017 by prabhakaran

[prabhakaran]

Has been confirmed as a limitation by NI. The maximum row width which will be supported will be 2600. No workaround as yet.