Do you have hundreds or thousands of digital photos which occupy a noticeable part of your hard-drive or a pile of CDs? Article explains how to make the files with pictures much smaller and save a lot of storage space.
As you probably know, JPEG file format is widely used in digital cameras because it can reduce the size of the files containing pictures dramatically. But people never stop from wanting to get more... Can you get more? Do you have hundreds or thousands of digital photos which occupy a noticeable part of your hard-drive or a pile of CDs? Did you know that you can re-use JPEG and save some storage space on the pictures? Read on to know how.
Idea is very simple. Every JPEG file has a certain parameter, quality. The greater is quality, the better is picture, the large is JPEG file size. By default, digital cameras usually store high-quality JPEG files. So, the size of the file is large, but quality is good. You can use that to have good-quality photo prints. But if you are just going to watch photos on the screen of the computer - much less JPEG quality is sufficient. Also you might not need all 4 or 6 megapixels (which does not fit the screen and in fact is resized when you are watching photos). So, we are going to do 2 things: resize photos (smaller photos take less space) and reduce JPEG quality parameter (this gives some hardly noticeable quality deterioration).
Any decent picture editing program can do this. There is a lightweight and quite powerful viewer IrfanView (it is free on www.irfanview.com), which we will use. Let's run a particular example. I pick a photo from my 4 mp camera. It has dimensions 2304 x 1728 and occupies 1,863,654 bytes. Now I open it in IrfanView, choose Image > Resize/Resample > Half > OK. The photo is resized now and has dimensions 1152 x 864. Let's save it with a smaller JPEG quality. Go to File > Save as ..., choose JPEG file type and show option dialog. In options let's pick quality = 70. (You can experiment with it, of cause, and try another value.) OK. It is saved. The size of new file is 134,525 bytes. Viewing any of two files full screen one cannot see any difference. But the new file size is only about 7% of the original. That's what you can do. Put 10 times more pictures into the same space! Actual savings may vary on the type of pictures - walls will occupy less than trees and faces...
You don't have to do all these manipulations manually for each file - there is a batch processing feature in IrfanView. So you can process a directory of files with several clicks. Do it like this: File > Batch Conversion/Rename. Add the files you want to compress to the list on the left, choose some output directory. Make sure that JPEG is output file type. Button "options" will allow you to choose output quality, e.g. 70. Button "advanced options" will bring up a menu where you can set resizing of the images, for example 50% of the original. That's all the recipe. Good luck!
