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Scaling, cliping and exporting, best methods? - Printable Version

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Scaling, cliping and exporting, best methods? - lkubler - 03-12-2018

Hi,

Running GIMP 2.8.10 on Windows 7 for now.  I have been asked to upload pictures of staff in to our email program so that when you send an email, to someone internal to our company, the picture is included so people see who you are.

We are running Exchange 2007 and its requirements for the pictures are 96x96 pixels and under 10KB in size, jpg file.  The pictures I have been given are in the realm of 5000x3864 pixels and 200MB so I need to pare them down.

I tried cropping and then scaling and that seemed to work except when I tried to export it to jpg it said the file size was around 20K.  So I tried to adjust the quality and to get to 10K but that left the subject of the picture unrecognizable.

Any suggestions on how to get there from here?  Is there a better order of operations or some other feature I missed that would help me meet the requirements but keep a reasonable picture?

Thanks in advance,
Linn


RE: Scaling, cliping and exporting, best methods? - rich2005 - 03-12-2018

Quote:...Running GIMP 2.8.10 on Windows 7...

That is an old version, seriously advise updating to the most recent Gimp 2.8.22 see: http://www.gimp.org

edit: This has just sunk in
Quote:....are in the realm of 5000x3864 pixels and 200MB...

My digital camera takes images about that size, jpegs are about 7 to 8 MB, a RAW image 23 MB
Converting to an uncompressed tiff and it is 54 MB.
What exactly is the image format?

-----------
You can try something like this.

1. Crop the image to a square. You can set the aspect ratio to fixed and the ratio to 1:1

screenshot: https://i.imgur.com/znZYM0J.jpg

2. Scale down to 96 x 96 pix, Use Sinc(Lanczos3) for the interpolation

https://i.imgur.com/zfkO4sG.jpg

3. No screenshot for this but try a little sharpen Filters -> Enhance -> Unsharp mask try default values.

4. Export as a jpeg. tick the Show preview in image window box, that will give a size estimate just above.  Untick all the unnecessary items - Exif etc. Set the sub-sampling to 4:2:2 Adjust the quality setting to get the file size.

https://i.imgur.com/xLZD5Ub.jpg

And it should not be too bad, it is for an email after all. showing at 300% https://i.imgur.com/5oDxJkj.jpg

How many of these to do? Might be possible to use a batch file, all depends on the position in that first procedure, cropping to a square.


RE: Scaling, cliping and exporting, best methods? - lkubler - 03-13-2018

(03-12-2018, 06:30 PM)rich2005 Wrote:
Quote:...Running GIMP 2.8.10 on Windows 7...

That is an old version, seriously advise updating to the most recent Gimp 2.8.22 see: http://www.gimp.org

edit: This has just sunk in
Quote:....are in the realm of 5000x3864 pixels and 200MB...

My digital camera takes images about that size, jpegs are about 7 to 8 MB, a RAW image 23 MB
Converting to an uncompressed tiff and it is 54 MB.
What exactly is the image format?

-----------
You can try something like this.

1. Crop the image to a square. You can set the aspect ratio to fixed and the ratio to 1:1

screenshot: https://i.imgur.com/znZYM0J.jpg

2. Scale down to 96 x 96 pix, Use Sinc(Lanczos3) for the interpolation

https://i.imgur.com/zfkO4sG.jpg

3. No screenshot for this but try a little sharpen Filters -> Enhance -> Unsharp mask try default values.

4. Export as a jpeg. tick the Show preview in image window box, that will give a size estimate just above.  Untick all the unnecessary items - Exif etc. Set the sub-sampling to 4:2:2 Adjust the quality setting to get the file size.

https://i.imgur.com/xLZD5Ub.jpg

And it should not be too bad, it is for an email after all. showing at 300% https://i.imgur.com/5oDxJkj.jpg

How many of these to do? Might be possible to use a batch file, all depends on the position in that first procedure, cropping to a square.

Oh yeah, that is much better.  Followed your steps and it worked well.  The Unsharp mask suggestion helped as did turning off advanced options in the Export.  File size really came down once I unchecked Save EXIF data, Save thumbnail, Save XMP data and Use quality settings from the original image.

I've only got 12 or so to do so far so I'll probably not bother with batching.  Surprisingly, having your picture posted on every email you send isn't all that popular around here.  So far it is voluntary.  

Thanks much for the help,
Linn