Picasa: quick and easy photo editing for free

Picasa is a great free photo organiser and editor and you can find and download it from picasa.google.com. Here are some of the key editing features in Picasa. If you already use Picasa, I suggest you update your version now. In past versions, edits you make in Picasa were only visible in Picasa and were not saved with the image unless you exported it. The new version avoids these problems.

1. To edit an image, from the main screen (called the Library), double click the image to open it in the editor. To straighten a photo, select the Straighten tool and drag the slider to the left or right to rotate the image until it is straight – use the grid as a visual guide to gauge when it is straight. Click Apply to apply the fix and crop the uneven edges from the image.
   
2. To lighten an image where the subject is in shadow, choose the Tuning tool and drag the Fill Light slider to bring the detail out of the shadows – this mimics using the fill flash on your camera. The Temperature slider adjusts the colour of the light in the image, drag it to the right to add yellow to the image and to the left to add blue.
   
3. To fix an image with poor contrast you have two options. The first is to use the Auto Contrast fix in the Basic tools. If the fix isn't enough or still needs some tuning, select the Tuning tab and adjust the Highlights and Shadows until you get the desired result. To fix a batch of images, select them in the Library by Control + clicking on them and choose Picture, Batch Edit, Auto Contrast.
   
4. To crop an image for printing, select the image and choose the Crop tool. To crop for 4 x 6 printing, choose the 10 x 15 option (the ratios are the same) and drag over the image. Drag on the edges of the shape to size it larger or smaller but still in the correct proportions. Click Apply to apply the change to the image.
   
5. When you've finished working on an image, sharpen it using the Effects menu and choose the Sharpen option. You can use this tool multiple times if needed to sharpen the image – every time you click it, the image is sharpened a little more. If you sharpen too much, click the Undo button to roll back the changes. An image you will print should be sharpened more than one you'll simply preview on the screen.
   
6. To turn an image into a black and white image, choose the Effects, Filtered Black and White. Click the Pick Color box and test the colours that appear – each will give a slightly different black and white image based on the colours in the original image – pick the version that looks the best – ie where there are best variations between dark and light areas.