replace PImage.copy in P3D ?

Programming Questions

pauline303

in Programming Questions • 6 months ago

Hi,
I would like make some blobs detection which uses PImage.copy.
Unfortunately there's kind of bug using this into P3D mode. (the image freezes in very strange way…).
Anyway, how could I replaced PImage.copy in this code :

void draw()
{
if (newFrame)
{

    image(cam, 0, 0, width, height);
    img.copy(cam, 0, 0, cam.width, cam.height,
    0, 0, img.width, img.height);
    fastblur(img, 2);
    theBlobDetection.computeBlobs(img.pixels);
    drawBlobsAndEdges(true, true);
newFrame=false;
}
}

And another point: when I do this:

if (newFrame) { newFrame = false;………………………

the rest of the loop is not read and the image is still grey, which is not the case in "normal renders".
I couldn't found any docs about the difference between P3D and others renders…would be very interesting for me to know how P3D handles things, priority…

thanks in advance

Replies(1)

PhiLho

Re: replace PImage.copy in P3D ?

6 months ago

The way you use img.copy(), for copying the whole image, can be easily replaced (with speed and perhaps memory gain!) with loadPixels() of both PImage / PGraphics, arrayCopy() of the pixels[] array and updatePixels() of the target.
I let you look up these functions in the Reference, if you don't know them already.

" would be very interesting for me to know how P3D handles things, priority"
First, why do you need a P3D mode to manage a 2D camera capture? Are you doing 3D drawing beside this part?
Second, the answer depends on the version of Processing you use. In 1.5.1 and before, it was a special bitmap mode, with drawings managed by Processing. Now, it is just an OpenGL mode, Where things like bitmap (pixel access) and smoothing are managed differently.

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