Skip optipng if it reduced the color type from rgb to grayscale/grayscale+alpha.

Skip optipng if it reduced the color type from rgb to grayscale/grayscale+alpha.

There seems to be a bug in optipng's bit depth reduction when coverting to grayscale.
We don't know exact condition, but its savings is relatively small, so
we should just skip this process for grayscale images.

BUG=174505
TEST=none
NOTRY=true

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=181170

[Nico, 2013-02-06 21:53:30]

Sorry, missed this.

https://codereview.chromium.org/12224023/diff/7001/build/sanitize-png-files.sh
File build/sanitize-png-files.sh (right):

https://codereview.chromium.org/12224023/diff/7001/build/sanitize-png-files.s...
build/sanitize-png-files.sh:228: # crbug.com/174505, crbug.com/174084.
Should we fix this in optipng instead? Have you at least reported this to
upstream optipng?

[oshima, 2013-02-06 22:34:09]

https://codereview.chromium.org/12224023/diff/7001/build/sanitize-png-files.sh
File build/sanitize-png-files.sh (right):

https://codereview.chromium.org/12224023/diff/7001/build/sanitize-png-files.s...
build/sanitize-png-files.sh:228: # crbug.com/174505, crbug.com/174084.
On 2013/02/06 21:53:30, Nico wrote:
> Should we fix this in optipng instead? Have you at least reported this to
> upstream optipng?

Filed a bug and added the reference.

[Nico, 2013-02-06 22:46:23]

lgtm, thanks

https://codereview.chromium.org/12224023/diff/10001/build/sanitize-png-files.sh
File build/sanitize-png-files.sh (right):

https://codereview.chromium.org/12224023/diff/10001/build/sanitize-png-files....
build/sanitize-png-files.sh:195: echo $(identify -verbose $file | awk
'/IHDR.color_type/ {print $3}')
can you base this on the output of `file` instead of `identify`? that's more
readily available i think. not important though.

[oshima, 2013-02-06 23:30:37]

PTAL

https://codereview.chromium.org/12224023/diff/10001/build/sanitize-png-files.sh
File build/sanitize-png-files.sh (right):

https://codereview.chromium.org/12224023/diff/10001/build/sanitize-png-files....
build/sanitize-png-files.sh:195: echo $(identify -verbose $file | awk
'/IHDR.color_type/ {print $3}')
On 2013/02/06 22:46:23, Nico wrote:
> can you base this on the output of `file` instead of `identify`? that's more
> readily available i think. not important though.

Done.

[Nico, 2013-02-06 23:34:56]

still lgtm

https://codereview.chromium.org/12224023/diff/12001/build/sanitize-png-files.sh
File build/sanitize-png-files.sh (right):

https://codereview.chromium.org/12224023/diff/12001/build/sanitize-png-files....
build/sanitize-png-files.sh:18: 
Should this have a `set -e` `set -u` up here?

[oshima, 2013-02-06 23:46:23]

https://codereview.chromium.org/12224023/diff/12001/build/sanitize-png-files.sh
File build/sanitize-png-files.sh (right):

https://codereview.chromium.org/12224023/diff/12001/build/sanitize-png-files....
build/sanitize-png-files.sh:18: 
On 2013/02/06 23:34:56, Nico wrote:
> Should this have a `set -e` `set -u` up here?

Good catch. I overlooked it. Since I need to fix
a few places, I'll do that in separate CL.

[Nico, 2013-02-06 23:52:11]

On Wed, Feb 6, 2013 at 3:46 PM,  <oshima@chromium.org> wrote:
>
>
https://codereview.chromium.org/12224023/diff/12001/build/sanitize-png-files.sh
> File build/sanitize-png-files.sh (right):
>
>
https://codereview.chromium.org/12224023/diff/12001/build/sanitize-png-files....
> build/sanitize-png-files.sh:18:
> On 2013/02/06 23:34:56, Nico wrote:
>>
>> Should this have a `set -e` `set -u` up here?
>
>
> Good catch. I overlooked it. Since I need to fix
> a few places, I'll do that in separate CL.

sgtm!

>
> https://codereview.chromium.org/12224023/

[commit-bot: I haz the power, 2013-02-07 00:02:57]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/oshima@chromium.org/12224023/12001