# Revision history [back]

I am running into a similar problem with copyTo using the UMat container. Did you find any resolution?

k = 0;
for (int i = 0; i < y5_u.rows; i++) {
if (i % 2 == 0)
y5_u.row(i).copyTo(y4_u.row(k++));
}

y4_u.copyTo(out);


y4_u, y5_u, and out are UMats. The sizes are 640x480 and smaller. This snippet takes approximately 15 ms which is more than twice as slow then when on the CPU. Any insights on a path forward would be greatly appreciated!

-Matt