I’m not one for buying into the Adobe Illustrator and Photoshop hype. They’re prohibitively expensive and yet everyone is expected to use them. What I do to convert raster images to Vector is I use a free image programme called Inkscape. Drag your raster file into an open Inkscape window, click yes to embed it. Then select the image, in the top menu bar click Paths, then trace bitmap. There’s a variety of options available in the new window that opens. I usually select Colour, then deselect the first tick box (stack layers), select the second and the third (remove background). Then choose how many colours you want to keep. Now obviously for Vector images, the original image needs to be fairly simple in terms of colour and effects. Trying to turn a photograph into a Vector for example is going to cause serious headaches. Cartoony stuff with flat fill colours, no gradients – that sort of thing is what you want. Choose the number of colours that are in the image, then click OK and it’ll convert it to a vector. If you notice a loss of colour in the new image, delete it, select your original image again and up the number of colours you want to keep. button (in the Control panel at the top). The Live Trace dropdown offers a number of options depending on the type of vector you are looking for, e.g. Silhouette, Line Art, High-Fidelity Photo etc It’s important to note that while all graphics can be converted to vectors, the results (both quality-wise and size-wise) aren’t always pretty. You may need to prep the raster image in Photoshop first to cut down on the number of colours and simplify it to the maximum extent acceptable to you. Of course, it is. Bert Monroy (you really should Google him to see his work on the web) built a career out of creating extremely detailed Illustrator renderings that started out as photographs back in the early 1990’s when auto-trace algorithms were uncommon and artists went to places like The Center for Creative Imaging to learn how to artistically use computers. Personally, I would never use an auto-trace feature unless it was a simple piece of art that I intended to throw away. I always get better results recreating the artwork by hand using Photoshop’s pen tool and then copying the vectors to Illustrator where I complete the design. The reason for tracing in Photoshop is because of the pixel accuracy. When I did quite a bit of this sort of work, the pixel accuracy in Illustrator was terrible, but Photoshop let you blow things up and draw your vector right through the middle of a pixel if you wanted. Illustrator might be better now, I haven’t tried it lately. Bezier curves are wonderful things once you learn how to control them. It’s not hard, but it’s not intuitive, either. You just need to understand how to bend lines through anchor points and anticipate how they will travel on the other side of the anchor. If your raster graphic has minimum colors and doesn’t have gradient color fills than you can use Adobe Illustrator’s Live trace Tool or Corel Draw’s Quick Trace tool. But At the End you might need to manually edit or recreate some portion of the graphic. Rasters are pixels with color values. You must have noticed when you scale up or zoom in to images, they ‘tear’ up – that’s basically because the image is made of pixels and is resolution-dependent. Vectors, on the other hand, are mathematical curves that are resolution-independent. You can manipulate them at any size. There may be times when you need to import images and graphics into a graphics program for design (logos, artwork, print etc.) – converting which to vectors gives better control. Some softwares have conversion algorithms but the best results are often when done manually – which can be a tedious process. that enables the conversion from a raster bitmap images like JPEG, BMP and PNG to a scalable vector graphic with a few simple clicks. Source.