Resizing Images to a specific size

[Parmcat]

Hello there,

I am trying to submit some pics to my loacal Camera club photo contest. They are specific that the max size is 1024x768 and a max of 500kb.

I have downloaded "The Gimp" and it works very well, but when you resize the width to 1024, the height is still bigger then 768. If I now try to resize the height to 768, the width shrinks.

Is there a program that I can use to make a picture a specific size?

Thanks in advance

Parm

[John_B]

Parmcat,
My suggestion is try to resize it as close to the 1024 x 768 you can get ex. 1200 x 800 px then cut out a 1024 x 768 px crop from the photo. This way you don't alter its aspect. It can be done pretty easily with the software that comes with the cameras.
Hope that helps :D

[tummelvalley]

I know that in Photoshop there is a "constrain proportions" box that you tick so when you resize one dimension the other changes to keep the same proportion. Is there maybe a similar one in the GIMP?

[StewartR]

Parmcat, you don't want to resize the picture to exactly 1024x768 because you'd be changing its proportions and thereby distorting it - squeezing or stretching.

You need to think about the aspect ratio (http://en.wikipedia.org/wiki/Aspect_ratio_(image)) of your picture. For shots straight out of the camera it's 1.500; if you've cropped the image at all then it's likely to be different. The maximum dimensions that the club specify, 1024x768, has an aspect ratio of 1.333.

If your image has an aspect ratio greater than 1.333, then the best you can do is 1024 pixels on the long side and something less than 768 on the short side; for example an image straight out of the camera will resize to 1024x683.
If your image of has an aspect ratio less than 1.333, then the best you can do is 768 pixels on the short side and something less than 1024 on the long side; for example a square image will resize to 768x768.

[gasrocks]

I use Irfanview. As I am dragging, making the new sized box, the number of pixels is shown on the screen. I watch that and make it any size I want.

[DavidW]

Putting it simply, 1024x768 is not the same aspect ratio as a Canon DSLR. If you wish the final image to be in a different aspect ratio without distortion, then you must crop the image to the appropriate aspect ratio.

Aspect ratio is simply the width divided by the height.



David

[dmp-potn]

Hello,

Hello there,

I am trying to submit some pics to my loacal Camera club photo contest. They are specific that the max size is 1024x768 and a max of 500kb.

I have downloaded "The Gimp" and it works very well, but when you resize the width to 1024, the height is still bigger then 768. If I now try to resize the height to 768, the width shrinks.

Is there a program that I can use to make a picture a specific size?

Thanks in advance

Parm

If you're on Linux, something like this should work:

$ convert -geometry 1024x768 -quality 85 +profile '*' orig.jpg new.jpg

Although this sounds like it will change the aspect ratio of the final image, it won't. It will just scale the image to make it fit into 1024x768px. In my test case, I started with a 3072x2040px image (roughly 3:2 aspect ratio) and ended with a 1024x680px file that was around 300KB.

You need to install ImageMagick, but that's probably already there. I believe that there is a Windows verson as well, but I've not tried it. Good luck.