If you integrate Vision HDL Toolbox designs with algorithms that use a different interface, you may need to create the structure manually, or manipulate the control signals outside of the structure.

Create a pixelcontrol structure by passing five control signal values to the pixelcontrolstruct function. The function arguments must be scalar values. These control signals may come from a camera or other video input source. The control signal vectors in this example describe a simple 2-by-3 pixel test image, surrounded by padding pixels.

hStart = [0 0 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0];
vStart = [0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0];
hEnd   = [0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 0];
vEnd   = [0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0];
valid  = [0 0 0 0 0 0 0 1 1 1 0 0 0 1 1 1 0 0 0 0 0 0 0 0];
pixel = uint8([0 0 0 0 0 0 0 30 60 90 0 0 0 120 150 180 0 0 0 0 0 0 0 0]);
[~,numPix] = size(pixel);
ctrlIn = repmat(pixelcontrolstruct,numPix,1);
for i = 1:numPix
    ctrlIn(i) = pixelcontrolstruct(hStart(i),vStart(i),...
                                   hEnd(i),vEnd(i),valid(i));
end

Each element of ctrlIn is a structure containing the five control signals.

ctrlIn(8)

ans = struct with fields:
    hStart: 1
      hEnd: 1
    vStart: 0
      vEnd: 0
     valid: 1

You can then pass this structure to a Vision HDL Toolbox System object. This example uses the LookupTable object to invert each pixel.

Note: This object syntax runs only in R2016b or later. If you are using an earlier release, replace each call of an object with the equivalent step syntax. For example, replace myObject(x) with step(myObject,x).

tabledata = uint8(linspace(255,0,256));
inverter = visionhdl.LookupTable(tabledata);
pixelOut = zeros(numPix,1,'uint8');
ctrlOut = repmat(pixelcontrolstruct,numPix,1);

for i = 1:numPix
    [pixelOut(i),ctrlOut(i)] = inverter(pixel(i),ctrlIn(i));
end

If you need to use the control signals directly in downstream algorithms, you can flatten each structure into five logical control signal values by calling the pixelcontrolsignals function.

[hStartOut,vStartOut,hEndOut,vEndOut,validOut] = deal(false(numPix,1));
for i = 1:numPix
    [hStartOut(i),vStartOut(i),hEndOut(i),vEndOut(i),validOut(i)] = ...
        pixelcontrolsignals(ctrlOut(i));
end

Each output control signal is a vector of logical values that correspond with the pixelOut vector.

validOut'

ans = 1x24 logical array

   0   0   0   0   0   0   0   0   0   1   1   1   0   0   0   1   1   1   0   0   0   0   0   0