Inkscape has become a popular, free alternative for Adobe Illustrator. The software specializes in dealing with vector graphics, and you can use it for editing raster images as well.
Once you are used to using Inkscape for vector graphic design, it is natural to try and avoid switching to an image editing app for a minor task related to handling a raster image. The good news is Inkscape can perform a lot of basic image editing tasks.
So, there is no need to switch between apps. Here’s how you can edit raster images and improve image quality using Inkscape.
Difference Between Raster Images and Vector Graphics
Most of the digital images and pictures you see on the web are raster graphics images or bitmaps. In simple words, a raster graphics image is a set of particular colors on a grid of pixels. A raster image is resolution-dependent, and you cannot make it larger without loss of apparent quality.
Therefore, it is better to use vector graphics for images that need to be scaled to a higher resolution. Images rendered using vector graphics will scale to any size and still maintain smooth edges. This format is ideal for dealing with things such as fonts and logos.
Improving Image Quality in Inkscape
Using Inkscape, you can convert pixel images to vector graphics. It can also improve the quality of your image by either converting it to a vector, increasing image resolution, sharpening it, or a combination of all three.
SVG (Scalable Vector Graphics) is a vector graphics file format. And that’s the format we’ll be converting our image into for this demonstration. First, you will need to download Inkscape and install it. It’s available for Linux, Mac, and Windows. So, you can use it on pretty much any machine.
Once you’ve installed Inkscape, launch it and open the raster image you want to convert by going to File > Open and locating the file. Converting it to an SVG file will allow you to scale it to any size and maintain the smooth edges.
Select the entire image by navigating to Edit > Select All in the Inkscape menu or pressing Ctrl + A on your keyboard. Then go to Path > Trace Bitmap or press Shift + Alt + B on your keyboard. Alternatively, you can also right-click on the image and click on Trace Bitmap.
In the Trace Bitmap dialog, select Colors under Multiple scans and be sure to uncheck Smooth. Click the OK button. The conversion will take place, but the dialog box will stay open on the screen.
Close the dialog box by clicking the X in the upper right corner. Next, you have to get rid of the original image lying beneath the trace you just performed. The one on top is your vector graphic.
Go to Object > Lower to Bottom or press the End key on your keyboard to view the original.
Now the original image should be on top. Click on it to select it and then press the Delete key on your keyboard. You should now be seeing your picture in the form of a vector.
Next, save the file by navigating to File > Save As. Give the file a new name, and ensure that the file type in the bottom right is Inkscape SVG. You can make this SVG image as big as you want without pixelating it.
Here is a side-by-side comparison of the vector (Left) and the original raster image (Right) after enlarging.
As you can see, the edges of the vector are smooth, while the raster image has pixelated edges. If you’d like to sharpen your image further, you can go to Filters > Image Effects > Sharpen or Sharpen More. This is how you can sharpen an image in Inkscape.
Unlock the Image Editing Potential of Inkscape
Now that you know the methods of handling raster images in Inkscape, you can do the basic image editing tasks within the app. You won’t need to switch to GIMP or Photoshop every now and then, breaking your rhythm of work.