The basic reason behind optimizing an image is to make it look better and load faster. You don’t need Photoshop or complicated IT skills to achieve it. An online tool called webresizer can help.
Browse for the image (.GIF, .JPG and .PNG) you want to optimize, then click upload image (up to 5M) to load it into the web resizer.
Websizer has many useful features: sharpen, border preview, resize image, rotate, increase contrast, exposure, color saturation, and convert a photo to black and white.