Digital Picture Question

[pamato]

I have a JPEG picture that is 1.1 MB and I need to compress it and make it smailler, about 200 kb. Does anyone know how or if I can do this? I am attempting to attach pics to a post, but I didn't realize how much memory these pics take up. Any suggestions?

thanks

[mikeg]

Originally posted by pamato
I have a JPEG picture that is 1.1 MB and I need to compress it and make it smailler, about 200 kb. Does anyone know how or if I can do this? I am attempting to attach pics to a post, but I didn't realize how much memory these pics take up. Any suggestions?

JPEG is already a compressed format, so using another compression routine will usually make the file bigger.

What you want to do is resize the picture. It's probably a gazillion X two gazillion pixels. A good image software suite like Photoshop or The Gimp will do an excellent job of resizing it without making it look terrible. Most pictures look OK on the screen even if they are resized to something like 600x800 pixels, or even less.

[Looney]

Resizing and other simple stuff: Irfanview.

More complicated stuff: The Gimp.

[pamato]

thanks for the suggestions, the picture is huge when I looked at the pixels. I have some imaging software at home and I will attempt to resize it, so I can post some pics.

Paul

[atomic80]

OR if you want to REALLY make it easy...use the "Image Resizer" tool from the XP Powertoys collection (that is, if you have Windows XP). Get it from here.

After you've installed this simple program, all you have to do is right click on the image file and choose "Resize Pictures" and it'll ask you what size you'd like. Most tend to go with 800x600. You can even do multiple images at the same time too. Only caveat with this program is that it adds "(Small)," "(Medium)," or "(Large)" to the file names. I just rename those.

[r0ckrat]

Originally posted by atomic80
Only caveat with this program is that it adds "(Small)," "(Medium)," or "(Large)" to the file names. I just rename those.

Using the Advanced mode, you can alter the suffix that is applied to the images. This is nice, as it won't (although it can if you let it) overwrite your original photos. (Of course, you have them all backed up to CD, right? )

[atomic80]

You sure? I just tried that and I don't see anything that would change those settings.

[mikeg]

When resizing images, there are some techniques to keep in mind. You can scale the image, crop the image, or both. Scaling the image loses detail, while cropping the image loses image area.

The best results usually come from first cropping the image so that only the bits you actually think are necessary are left, THEN scaling the cropped image down to the size you want it to be. Because you have cropped it first, you don't have to scale it as much, thus leaving more detail. This technique is especially important in making "thumbnail" images, in which it is better to recognizibly show part of the full picture than it is to show a very tiny blob that supposedly shows all of the full picture.

Furthermore, when scaling you probably want to retain the aspect ratio of the original, unless you intentionally want it to be distorted. And you always want to scale down rather than up, because it is easier to throw away some of the pixels than to interpolate new ones.

Finally, if you plan to do any image manipulation, it is usually best to do that before you do any cropping or scaling. The exception is adding text to the image, which is best done on top of the final image so the text does not get cropped or scaled.

[r0ckrat]

Oh - your right. No way to reset name, but if you copy the pictures to a different folder you can check the box to "Resize the original pictures (don't create copies)" which will eliminate the extra text.

[pamato]

thanks for all of the great info. I downloaded the image resizer and I will attempt to alter the size. I will keep everyone informed.


Paul

[Looney]

Originally posted by mikeg
The best results usually come from first cropping the image so that only the bits you actually think are necessary are left, THEN scaling the cropped image down to the size you want it to be. Because you have cropped it first, you don't have to scale it as much, thus leaving more detail. This technique is especially important in making "thumbnail" images, in which it is better to recognizibly show part of the full picture than it is to show a very tiny blob that supposedly shows all of the full picture.

Yep. And how much framing you want to leave in will also vary by the size of the pic.









If you have Photoshop, you can also save at a reduced quality for faster web downloads, and save a jpeg as Prograssive, so it downloads in stages.

[mikeg]

Originally posted by Carrie B
If you have Photoshop, you can also save at a reduced quality for faster web downloads, and save a jpeg as progressive, so it downloads in stages.

The Gimp can also do that, BTW.

Lots of other tricks are available as well, but the main one is just not making the image too big or too detailed in the first place. The quality of image needed for display on a screen is much less than the quality of image needed for photo-quality printout. So you need to decide whether your image is intended for printing or only displaying.