Wednesday, 26 January 2011

making a sketch

Step 1: Duplicate The Background Layer

With my photo newly opened inside Photoshop, I currently have one layer, my Background layer, which contains my image:
The Background layer containing my image
Photoshop tutorial: My newly opened image on the Background layer.
The first step in creating this sketch effect is to duplicate this layer, and the easiest way to do that is with the keyboard shortcut,Ctrl+J (Win) / Command+J (Mac). This gives me my copy of the Background layer, as we can see in the Layers palette:
The Layers palette after duplicating the Background layer
Photoshop tutorial: The Layers palette now with two layers after copying the Background layer.

Step 2: Desaturate The Layer

The second step is to desaturate this newly created layer (which Photoshop has named "Layer 1"). Now there's plenty of ways to getprofessional quality black and white conversions of images, but that's overkill for what we're doing here. All we need is a quick way to remove the colors from the image, and the quickest way to do that is to desaturate the image using the keyboard shortcut,Shift+Ctrl+U (Win) / Shift+Command+U (Mac).
Desaturate the copy of the Background layer
Photoshop tutorial: Use the keyboard shortcut to quickly remove the color from the image.

Step 3: Duplicate The Desaturated Layer

Next, we need a copy of this desaturated layer, so once again, let's use the handy keyboard shortcut, Ctrl+J (Win) / Command+J(Mac):
Duplicate the desaturated layer
Photoshop tutorial: Use the keyboard shortcut once again to quickly duplicate the desaturated layer.

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:
Press Ctrl+I (Win) or Command+I (Mac) on the top layer to invert it.
Photoshop tutorial: Invert the image using the keyboard shortcut "Ctrl+I" (Win) / "Command+I" (Mac)

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 "ColorDodge". 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:
Change the blend mode to Color Dodge
Photoshop tutorial: Change the blend mode for the inverted layer from Normal to Color Dodge.
This will temporarily turn the image white:
The image appears white after changing the layer blend mode to Color Dodge
Photoshop tutorial: The image now appears to be filled with 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:
Select Filter > Blur > Gaussian Blur
Photoshop tutorial: Filter > Blur > Gaussian Blur
This brings up the Gaussian Blur dialog box:
The Gaussian Blur dialog box
Photoshop tutorial: Photoshop's 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:
The original image
Photoshop tutorial: The original photo as it was newly opened in Photoshop
And here's the result of my sketch effect:
The sketch effect
Photoshop tutorial: The photo converted into a sketch.
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.

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