Photo Effects: Turn A Photo To A Sketch

Step 4: Invert The Layer

Now that we have a copy of the desaturated layer, we need to invert it, which basically means we're going to swap the light and dark areas, so black becomes white, white becomes black, darker shades of gray become lighter and lighter ones become darker. Again, we can use a keyboard shortcut for this, Ctrl+I (Win) / Command+I (Mac). This gives us what looks like a "negative" version of the image:

Step 5: Change The Blend Mode Of The Inverted Layer To 'Color Dodge'

With the top layer (the inverted layer) still selected in the Layers palette, change the blend mode for this layer from "Normal" to "Color Dodge". You can do that by going up to the top of the Layers palette and clicking on the down-pointing arrow to the right of the word "Normal", and then select "Color Dodge" from the drop-down list:

This will temporarily turn the image white:

Step 6: Apply The Gaussian Blur Filter To The Color Dodge Layer

And here we are already at step six, the final step to giving us our sketch effect. All we need to do at this point is apply a Gaussian Blur to the Color Dodge layer.

To do that, with the Color Dodge layer (the top layer) selected in the Layers palette, go up to the Filter menu at the top of the screen, select Blur and then select Gaussian Blur from the list of blur filters:

This brings up the Gaussian Blur dialog box:

The key to achieving a nice sketch effect here is to adjust the Radius amount at the bottom of the Gaussian Blur dialog box until your image looks like a sketch. The easiest way to adjust it is to click on the slider bar at the very bottom and drag it with your mouse. As you can see in my screenshot above, the preview area in the Gaussian Blur dialog box won't do you much good here because it's still showing the inverted image, so you'll want to keep an eye on the image itself as you're dragging the Radius value left and right. Generally speaking, a lower Radius value works best. If you set the value too high, you'll overdo it and lose the effect.

I'm using a low resolution image for this tutorial, so for me, a Radius value of about 1 pixel gives me a nice sketch effect. You'll most likely be working on a much higher resolution photo, and in that case, you may find that a Radius value of around 4 or 5 gives you the desired results.

Here's the original photo once again, before we started working towards the effect:

And here's the result of my sketch effect:

If you're happy with your sketch effect, you can stop here. If you find, as I'm finding with my image, that the effect appears too light and could use some darkening to give it better contrast, finish up with these next couple of steps. Don't worry, they only add a few more seconds to the whole process.