Here is a quick and easy way to convert a rasterized image such as a bitmap, png, or jpeg into a vector graphic using Inkscape. The results can be adequate for most images right off the bat without too much editing. The first thing you need to do is locate your bitmap image file that you would like to convert to a vector graphic. Here, we will use this .png of a fruit fly:
Inkscape has the ability to open typical image formats, so go ahead and click your bitmap image file from Windows Explorer or whatever OS' file system you are using and drag it right into a blank canvas in Inkscape. Inkscape will open and display your bitmap.
You can move and re-size your bitmap image if you wish, but ultimately it will be deleted so do not worry too much about its placing in Inkscape. Now, we need to open the conversion dialog by selecting 'Path' and 'Trace Bitmap...' The shortcut for this dialog can also be displayed with 'Shift+Alt+B'. Go ahead and open the Trace Bitmap display.
Now that the Trace Bitmap dialog is displayed, the fun part begins with the options you have with the bitmap conversion to a vector graphic. The tool will scan your bitmap image and create nodes and paths based on your criteria selected. The top three options scan a single time, so your result will only be a black/white vector shape. This is often useful for more simple graphics such as cartoons, shapes, or logos. You may just need a vector mask of your graphic as well. Brightness Cutoff, Edge Detection, and Color Quantization can be selected and adjusted for various results. You can click 'Update' on the right for a preview of your resulting vector graphic. More often than not, you will want to perform multiple node path scans if you have a more complex color image. The bottom three multiple scan options provide Brightness Steps, Colors, and Greys scans. For each of these, you can adjust the number of scans that will take place. The more scans you select, the more paths your vector will have. This is a balancing act because the vector may appear much better or have more color depth, but it may be much larger in filesize. If you select many scans on a large complex bitmap image, it may also take a very long time to complete the vector graphic conversion. For our example fruit fly, we will select 'Colors' with 8 scans.
Once you are ready, click 'OK' to let the tool operate. You can watch the bottom status bar as it performs each scan and creates nodes based on your bitmap image. Once the trace bitmap completes, your new vector graphic will be displayed! One thing to remember is that your bitmap will still be present behind your vector, so you may want to go ahead and delete it if you wish. You can now resize and scale your new vector as you wish, or save it as a .svg!