Re: pngcrush and bugs 331068, 338659, 355693, 352177, 330026

["Nelson A. de Oliveira" <naoliv@gmail.com>]

Hi!

On 3/23/06, Andreas Tille <tillea@rki.de> wrote:
> On Thu, 23 Mar 2006, Alexander Schmehl wrote:
>
> > I have no strong feelings about pngcrush.  Just used it a couple of
> > times in the past and might need such a tool in the future, while not
> > knowing of similar tools.  It seemed to me, that no one else wanted it,
> > so I steped in.
>
> I'm sponsoring pngnq and pngquant for Nelson A. de Oliveira (CC).
> It might be reasonable to try to merge these three projects with
> similar functionality.  Perhaps asking the upstream authors whether
> they want to join their forces and make a great party in the time
> they might save be these means would make sense.

Actually, pngnq and pngquant are different from optipng (I maintain
this package too) and pngcrush.
The 4 programs are PNG optimizers, but they are different.
pngnq is based on pngquant. Both optimize PNG files reducing the
number of colors to 256 or less. They are lossy. The difference
between them is that each one use different algorithms to reduce the
color number. They are great if you need a small PNG file that can
lose some colors.

optipng is based on pngcrush. They are lossless optimizers. The user
won't loss any information from his/her PNG. Basically, they do the
same job.

I was reading this topic about pngcrush and optipng.
I have created the optipng package because pngcrush was in a bad
shape. And theorically, it can do all the things that pngcrush does.

I took 40 random PNGs from my system to make a test.
The total size of them is 4485 kbytes.
Running pngcrush (latest version, 1.6.2) without any arguments, they
were stripped to 4183 kbytes.
With optipng (version 0.5, without any options too), I've got 4126 kbytes.

As I could see, optipng generates slightly better images (in size), if
compared to pngcrush. However, it runs a little slower.

Maybe somebody could do a better test than mine, with more numbers. It
was just a trivial test that I did, to show what I see between both
optimizers.

Glenn (upstream author of pngcrush), said on
http://sourceforge.net/mailarchive/forum.php?thread_id=9575058&forum_id=43850:

'Or, check out Cosmin Truta's "optipng" program which is newer and
more powerful than pngcrush.'

Well, people have different opinions. There are people that like
pngcrush and if you ask a name of a PNG optimizer, they will say
"pngcrush".
Since optipng is newer, less people knows about it.
Both do a good work.

I don't know a good way to tell the upstream authors about merging programs.
I don't know why they started a new project based on an already
existent optimizers instead trying to work on the available programs,
but they had a reason for that.

The 4 programs are similar, but different. They are small too. If
there are users for all them, I don't see a problem in having they
available on Debian.
As I said, there are people that like one, others like the other.

Just my opinion. I don't know if it helped.

And please, CC me if answering this email.

Best regards,
Nelson