Hi Kieran,
On Thu, Dec 14, 2017 at 12:10 AM, Kieran Bingham <kbingham@xxxxxxxxxx> wrote:
> From: Kieran Bingham <kieran.bingham@xxxxxxxxxxxxxxxx>
>
> Provide a means to compare two identically sized framebuffers.
>
> This basic implementation expects the two buffers to have the same
> formats and sizes, and will return zero for identical frames, or a
> positive float representing and average difference otherwise.
an
> --- a/kms++util/src/verification.cpp
> +++ b/kms++util/src/verification.cpp
> @@ -18,4 +18,35 @@ void save_raw_frame(IFramebuffer& fb, const char *filename)
> os->write((char*)fb.map(i), fb.size(i));
> }
>
> +float compare_framebuffers(IFramebuffer& a, IFramebuffer& b)
> +{
> + // This expects a frame to be identical, including non-visible data.
> + for (i = 0; i < a.size(0) && i < b.size(0); i++)
> + diff += abs(pa[i] - pb[i]);
I think it's better to use "diff += abs(pa[i] - pb[i]) * abs(pa[i] - pb[i])",
to penalize larger differences.
See also https://en.wikipedia.org/wiki/Peak_signal-to-noise_ratio
> +
> + return diff / pixels;
> +}
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
