[magick-users] -quality not what I would expect - SOLVED

[Bob Meetin]

Glenn Linderman wrote:
> On approximately 9/21/2008 8:04 PM, came the following characters from 
> the keyboard of Bob Meetin:
>> Fred Weinhaus wrote:
>>> Just curious but have you tried putting -quality after -resize?
>>>   
>> For what it's worth, I put an example on my website using a different 
>> sample image at
>>
>> www.dottedi.biz/codesamples/convert/
>>
>> and switched the argument order.  And fixed that mistake.  Doesn't 
>> seem to help?
>>
>> see convert.txt for the commands I am running in convert.sh
>>
>> Also note that I uploaded some examples that I made up using GIMP.    
>> I'm shooting examples in the dark.  With GIMP 70% quality is just 
>> about where I would like it to be.  I gotta believe that that it's 
>> something simple I'm missing. It'd be so sweet if I could answer my 
>> own thread.....
>
>
> For a hint, try running
>
> identify -verbose one-of-the-pics.jpg
>
> on some of them.
>
> Note that what GIMP calls 70% may not be the same as what IM calls 
> 70%.  I don't ever recall hearing that the parameters are the exactly 
> the same in meaning.
>
> For another hint, note the "profile-exif" size... the IM files contain 
> profile-exif size comparable to the original picture; GIMP contains a 
> much smaller profile-exif size.  Once you add the option to remove the 
> profile (I forget, is it -strip ?) you might see more significant 
> differences in output sizes with various IM -quality settings.
>
> Personally, I think the GIMP 70% looks better than the IM -quality 70, 
> and even at IM -quality 90, the GIMP 70% looks brighter.  At that 
> size, it is hard to distinguish quality, though.
>
> And don't ask me what is in the profile-exif, but someone on the list 
> might know.
>
>
====>>>> PROBLEM SOLVED (pretty sure)

It was the profile.  I added "-strip" to several of the commands I was 
testing with the new image and it makes a world of difference. In my 
shell script I added it to an option to all of "noresize, 640px and 
180px".  I added the 640 px to make the result more viewable.  It 
appears that profile was adding around 38K to the base of this image, so 
even at 1% quality it was still minimally 38k+ in size.

Later I will clean up this test page.

-- 
Bob Meetin
www.dottedi.biz
303-926-0167

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