I just asked for a package for Rarig yesterday and Scoundrel already had to act twice at that thread. I'll try here to make it a productive post, that can be used by all.
I recently had to create a website for a girl-friend of mine, who is an artist and also has to learn almost everything about using a computer without sending her files accidently in the trash can.
So I asked her to bring her directories with the pictures of the frames she had painted, to create the galleries. I wouldn't use anything else than a command line with convert do change the 3 and 4 MB wide pictures into something that can fit in the galleries, of course, but later she will have to manage by herself. What can I do ? Teach here how to use Irfanview ? (win32 app). Teach here how to use ConversionMagick ? (win32 app too, a gpl gui to Image Magick) I tried that, she didn't understand anything about what things do there, although this one seems quite simple to me. I want to install PCLinuxOS in her machine and make her learn to use it, but I don't know yet if she has enough motivation to learn even the basics.
Anyhow very small app doing little, but right what we need to make pictures small very easily would be a very good idea. This can help under PCLinuxOS for the simple thing most people do at least once a while : send pictures to the family. We have to fancy that many many people just know how to start, shutdown and well, what is the difference between left click and right click ? You can't imagine how many times I have started to explain that to some friends of mine !
This intro is long enough now, the environment has been described.
Install Image Magick and it's depends.
One shell script I use:
for i in `ls *.*`;do convert $i -resize 25% -quality 85 -interlace line modif/$i ; done
#for i in `ls *.*`; do convert $i -rotate 270 alendroit/$i ; done
"modif" stands for modification. The script here after it converts an image to 25% of it's original size retains 85% of it's previous quality, makes it appear progressively (interlace line) and sends the result to the directory "modif".
This is good for batch resizing. 85% offers optimal ratio quality/weight. I have done tests with 80%, 90% and I came back each time to 85%. Sometimes I change 25% to another value, according to the first result I get.
This script is not perfect, as when I start it from the directory where there are images, it tries to convert itself as well, which results each time with an error. If you know how to fix it ?
The second part where it's commented is for eventual pictures not being correctly oriented. the option rotate can take other arguments, such as 90, and 180.
I also often add the "-strip" argument that takes of the exif informations, allowing to reduce the size of the image even more.
Resizing with Gimp : it is difficult to use for this purpose without loosing quality. There is a method, working on the canvas, but it's complicated, I have not succeeded in retaining how to do that the one time I was shown, and it's not ok for several images at same time.
ImageMagick gui : many menus, I use the one "view > resize", once a while when I have only one image to resize. Or I use the command line "convert -resize ... image_origine.png image_destination.png". In this case, you need to provide a name for the new image created.
There is a trick with "crop", I think, so that you can replace the image source by the image modified, but I'm not sure.
Another tool which is very nice to use, for batch resizing is fotoxx. I tried it recently and I found it to do even a better job than the command line ! The images I got from there were a bit smaller in weight that the ones with the Image Magick command lines (convert and options), and the images looked like there even had a nicer look.
For people who are very beginner I was told about and tried Rarig, for which I am requesting a package now:
(New) Rarig - image resizing made easy - http://www.pclinuxos.com/forum/index.php/topic,88565.0.html
Really easy, although I would have liked one or two more features in a program such as this one, but well, it's very very simple to use.
At the packages suggest thread, Ramchu and pirate state that KIM is enough for their needs : he men ! you're not alone around here, many people including me never use KDE !!! And therefore don't use Dolphin either !
Now I can say it, I'm not in packages request here !
Ok, please if you have more tricks for image resizing, you are welcome to continue the discussion.