Free software for re-sizing images (and other things)

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GrahamL
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Free software for re-sizing images (and other things)

Postby GrahamL » Sun 12 Feb 2017, 11:41

I was asked at the last meeting by a couple of members who don't possess one of the standard photo software packages about how to re-size images. I'd like to point folk to a couple of software packages that would be able to re-size images to the club's requirements. Other club members may want to add to this list or improve the background information.

1) 'Gimp' See https://www.gimp.org/
This is a free and open source software package that has well as providing quite powerful features can also very adequately re-size images to the appropriate jpeg format. It's available as freeware for both Windows, OS-X and Linux operating systems. May not be the easiest to use.

2) Software specific to a Windows system
Many possibilities, here's two;

a) Windows Live Photo Gallery and Movie Maker 2011, see https://www.microsoft.com/en-gb/download/details.aspx?id=29223
This 2011 software should still run on Windows systems, capable of quite a range of image manipulation tasks, including re-sizing.

b) FastStone Photo Resizer, see http://www.faststone.org/FSResizerDetail.htm
Does as described on the label.

3) Software specific to the Apple OS-X platform
I'm not an Apple/Mac user but I understand you can easily re-size using the system software; see http://osxdaily.com/2016/09/05/how-to-resize-photo-mac/

There are various tutorials out on the web. For instance:
http://www.simplehelp.net/2007/08/13/how-to-resize-images-using-the-gimp/
https://www.digitalunite.com/guides/digital-photography/editing-photos/how-resize-photos-windows-photo-gallery
https://davescomputertips.com/how-to-resize-photos-using-faststone-image-viewer/

Otherwise a search on YouTube is generally helpful in finding assistance. Please note I'm not a current user of any of these software packages and there is a lot of content out on the web if you go searching with the right terms.

IMPORTANT
Avoid loss of quality. The jpeg/.jpg format is compressable. As well as re-sizing the image to a smaller size, any jpeg image can be made a smaller file-size by compressing/removing pixels. That means if you stray from maximum or high-quality settings you may well find your image is less well resolved than you'd like. You probably do not want to do that with your images for competition use. Again, lots of guidance out there, for example: http://guides.lib.umich.edu/c.php?g=282942&p=1885347
This is particularly the case for software marketed to re-size for web or e-mail transmission. Take care.

Hope helpful. Haven't said much on colour profiling, just note that any club competition requires the jpeg image to be in Adobe's sRGB profile.

Graham Land
https://www.flickr.com/photos/photoviator/
TomWright
Posts: 2
Joined: Sun 13 Aug 2017, 11:11

Re: Free software for re-sizing images (and other things)

Postby TomWright » Sun 13 Aug 2017, 11:24

Thanks for making the list, that's really what my team and I need.
Personally I would one more point - https://macphun.com/luminar/resize-image. I resize photos with this tool (available for Mac). Not completely free, but it has a free trial. It depends how much photos you need to process, sometimes it's enough.
Mike Farley
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Joined: Tue 11 Sep 2012, 16:38
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Re: Free software for re-sizing images (and other things)

Postby Mike Farley » Mon 14 Aug 2017, 09:02

GrahamL wrote:Avoid loss of quality. The jpeg/.jpg format is compressable. As well as re-sizing the image to a smaller size, any jpeg image can be made a smaller file-size by compressing/removing pixels. That means if you stray from maximum or high-quality settings you may well find your image is less well resolved than you'd like. You probably do not want to do that with your images for competition use.

Thanks for this info, Graham.

The main issue with JPEGs is that the compression algorithm used is "lossy". The original purpose of the JPEG format was to create images with as small a file size as possible. That was back in the days around 30 years ago when disk storage was much more expensive than now. In order to optimise the compression, some information is discarded. For anyone shooting JPEG only, the main loss will occur in camera at the time the photo is taken. The principle casualty in respect of image quality will be a reduction in dynamic range. Since the main purpose of resizing images will be to reduce them to smaller dimensions, e.g. for DPI projection, any further deterioration in image quality is likely to be negligible. To minimise the losses, it is good practice to ensure the highest quality settings are used both when taking the photo and any subsequent editing.

That assumes the image is made from the in camera JPEG. Provided it is treated as a master copy which is never changed and from which any new images are created, there should not be any significant issues. It is only when a previously edited file is repeatedly resaved that problems really occur. Even then, it requires several iterations before degradation really becomes noticeable.

One further point and this really is nitpicking. In order to have a consistent naming convention across its product range, a while back Apple rebranded OS X as macOS. That brings it in line with the iOS operating system deployed on its iPhone and iPad offerings.
Regards

Mike Farley

Check out my website and latest blog post: http://www.mikefarley.net

My most recent images can be viewed at http://365project.org/pictor/365

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