Hi guys,

Me again.

As previously discussed, in order for the new jpeg-2000 plugin to be useful, it is
necessary to be able to save images with user selectable compression ratios.

I've taken a look at the jpg save setup in GIMP and have noted that there is a quality
slider, but, unless I'm missing something (which is possible - I only had a quick look),
it is not possible to interactively inspect the compressed image as the slider is moved.

This is inefficient because artists won't know what the compressed image is going to look
like until they open it up again. It would be far better to be able to adjust the image
quality in real time.

So, my question - does GIMP provide the ability to do the above in some way or do I need
to write code to open a temporary inspection window within the save callback ?

Follow on - this is some way off at the moment ... Jpeg-2000 supports rectangular regions
of interest (ROI) to enable some parts of an image to be compressed at different levels
from others, so for example, a sign with text could be compressed at high quality so you
can read it, whilst the background could be more fuzzy, as it's not so important to be
able to make out the detail so accurately. Is there some way we can mark rectangular
areas that don't get saved in the image, but that are available in the save routine for
ROI optimisation ? Layers ?

Thanks in advance for any assistance you are able to offer.

Best regards, Steve.

-------------------------------------------------------------------- mail2web.com - Microsoft® Exchange solutions from a leading provider - http://link.mail2web.com/Business/Exchange

Hi Martin,

Thanks for your prompt response.

Hackish is fine ...

Next job, locating the source to the jpeg plugin so I can grab the basics and merge ...

Best regards,
Steve.

Original Message:
-----------------
From: Martin Nordholts enselic@gmail.com Date: Sat, 15 Nov 2008 15:24:33 +0100 To: steve.williams@advance-software.com, gimp-developer@lists.xcf.berkeley.edu Subject: Re: [Gimp-developer] Interactive adjustment of image quality forlossy image
formats ...

steve@advance-software.com wrote:

Hi guys,

Me again.

As previously discussed, in order for the new jpeg-2000 plugin to be useful, it is
necessary to be able to save images with user selectable compression

ratios.

I've taken a look at the jpg save setup in GIMP and have noted that there is a quality
slider, but, unless I'm missing something (which is possible - I only had

a

quick look),
it is not possible to interactively inspect the compressed image as the slider is moved.

Hi Steve

Check the 'Show preview in image window' checkbox. The way it is implemented is rather hackish IIRC but there's a preview at least.

- Martin