[cairo] [Pixman] [PATCH 6/6] Add demos/zone_plate.png

[Siarhei Siamashka]

On Fri, 23 Nov 2012 23:15:31 -0500
Søren Sandmann <sandmann at cs.au.dk> wrote:

> From: Søren Sandmann Pedersen <ssp at redhat.com>
> 
> The zone plate image is a useful test case for image scalers because
> it contains all representable frequencies, so any imperfection in
> resampling filters will show up as Moire patterns.
> 
> This version is symmetric around the midpoint of the image, so since
> rotating it is supposed to be a noop, it can also be used to verify
> that the resampling filters don't shift the image.
> ---
>  demos/zone_plate.png |  Bin 0 -> 522879 bytes
>  1 files changed, 0 insertions(+), 0 deletions(-)
>  create mode 100644 demos/zone_plate.png

Hi, the size of this PNG file can be cut in half:

$ optipng -o7 zone_plate.png 
** Processing: zone_plate.png
512x512 pixels, 3x8 bits/pixel, RGB
Reducing image to 8 bits/pixel, grayscale
Input IDAT size = 522048 bytes
Input file size = 522879 bytes

Trying:
  zc = 9  zm = 9  zs = 0  f = 0		IDAT size = 231093
  zc = 8  zm = 9  zs = 0  f = 0		IDAT size = 231093
  zc = 7  zm = 9  zs = 0  f = 0		IDAT size = 231093
  zc = 6  zm = 9  zs = 0  f = 0		IDAT size = 231093
  zc = 5  zm = 9  zs = 0  f = 0		IDAT size = 231093
  zc = 3  zm = 9  zs = 0  f = 0		IDAT size = 228661
  zc = 3  zm = 9  zs = 1  f = 0		IDAT size = 228661
                               
Selecting parameters:
  zc = 3  zm = 9  zs = 1  f = 0		IDAT size = 228661

Output IDAT size = 228661 bytes (293387 bytes decrease)
Output file size = 228732 bytes (294147 bytes = 56.26% decrease)


-- 
Best regards,
Siarhei Siamashka