I want a software to compress photos especially JPEG photos. But it needs to be a free software. Also it shouldn't harm the quality of the photo. So what is the best free photo compressing software available?
There are tonnes, I tend to use Irfanview as it's small, fast and free. It also lets you batch resize whole folders of photos, which I find really useful for uploading to the likes of facebook or whatever. Basically anything that lets you save JPG format should give you an 'Options' choice before you finally click save, and that's the one which gives you a quality vs filesize slider. Higher the quality, higher the filesize. Start dropping the quality lower than about 80-85% and you'll start noticing artefacts in your photos.
Interesting facts: You can't compress compressed files using a lossless compression algorithm (you literally can, but the resulting file will probably be bigger). jpegs are alredy compressed and cannot have their file size reduced more without sacrificing resolution or compression quality or both. Changing the resolution of images on a computer by definition reduces image quality as you are reducing the number of pixels in the images and the resizing process arithmetically guesses what the colour of the remaining pixels should be based upon what the pixels near by used to be. Conclusion: If you want what you literally asked for, your aren't going to get it.
You can try compression techniques such as ZIP and RAR, but you likely won't see any compression or very small amounts, like 5-10%. JPEG is already compressed, and a losey compression technique at that. If you were talking something like an compressed Tiff or Bitmap, I'd say lay in to it, but Jpegs and Gifs are already compressed images. If you do have Tiffs or bitmaps laying around you could convert them to PNG files, as PNG is a pretty good compression technique and it is loseless.
Why not try putting it into MS Paint. If you want lossy then just rescale the image. JPEGs usually can't be compressed with lossless methods since they're one of the best standards for compressed images.
