The size of a digital image is something people forget about. They take a picture and it displays on their camera or phone just fine. They can download it to their computer, and most software can display it with no problems. People may not even notice the time it takes to load an image, or send it in email, if they have high-speed internet. However, there are two reasons size is important.
The most important is the size of the image file itself. I have a nice pocket camera that I carry all the time. It takes pictures as 4608X3456 pixel JPEG files. The problem is these files average around 5 MB in size. Some are as big as 6 MB. That means they take up a lot of disk space, and can take a long time to send over the internet. Some email programs won’t even let you send a file that large.
The other issue with size is the physical display required to see an image at full size. I have a 26″ HD compatible monitor, but it can only display 1920X1200 pixels. Some applications require much smaller images if you’re going to upload and display. Why waste space on your computer, or the server you’re uploading to, when you can resize an image to solve pixels and file size.
The picture above is a full size image of a bowl of wild strawberries I had for breakfast back in May. They were delicious. Click on this picture to see how big full size is. You don’t need a full screen image or larger to show people your breakfast. A nice 600X450 pixel image will do the trick. It will download faster, take much less disk space, and still show every luscious berry. In addition, the file size of the original image went from 4.18 MB to only 67 KB. That’s only 1.6% of the original size. Simply click on any image in this post to display it full size.
Resizing is simple. Startup PSP and load your image into the Edit workspace. Use the Image pull down menu to click on the Resize… selection.
This will open up the Resize window. There are a lot of controls on this window. First check the Advanced settings check box. Then check the Lock aspect ratio check box. That will keep the aspect ratio the same as you resize. This is very important so that you don’t distort your image.
Then make sure the units in the Pixel Dimensions section of the controls is set to Pixels instead of Percent. Now you can change the Width or Height value for the image and the other dimension will change automatically. Type 600 as the Width value and the Height will change as well. Depending on the original dimensions of the image you use, the Height may not end up as 450.
When the image size is correct, click on OK and the image will resize to the new dimensions you provided. Save your image file and you’re done.
GIMP is very similar. Start GIMP and load your image. Use the Image pull down menu to click on the Scale Image… selection.
This will bring up the Scale Image window. The units for Width and Height should be pixels again, as denoted by px. The aspect ratio is locked by clicking on the chain just to the right of the Width and Height. The chain will appear connected or broken. Connected means that the Width and Height are connected so the aspect ratio is maintained. Then simply modify the Width or Height to the new value desired. When done click on the Scale button to change the image size. Export the image file and you’re done.
PSP does a much better job of reducing the image file size than GIMP, but both produce files much smaller than original, and both produce the desired pixel dimensions. If you have any questions about resizing, leave them in comments and I’ll respond.