Sketches To Vector Image Tracing Without Illustrator
This post focuses on importing your scanned artwork and then converting those sketches to vector images while remaining within Photoshop. Once imported, we’ll clean up the sketch to remove the penciller’s marks, and then run an image trace Action on the result. Photoshop, unlike Adobe Illustrator, does not have direct support for generating vector shapes results through a sophisticated tracing panel UI. Photoshop does however, offer a suite of powerful, yet dispersed, set of features that can be stitched together to simulate an image tracing result.
In this post we will go through the process of generating the vector trace shape from the scanned sketch and then proceed to colourize the results.
- Tutorial Assets
- Scan And Import
- Run Image Trace
- Compare Adobe Shape Vector Result
- Coloring The Result…
Unlike Illustrator, Photoshop does not have native support for image trace, but with some creative tap dancing we can simulate results that are more than acceptible to use as filler content for a project — in some cases even as final artwork. Stipplr Actions are presets that prepare the selected source image in a specific way so that an expected result takes place — in the case of this tutorial we want a simple way of separating the line work from the background via a quick image trace applied to the source image. Stipplr Actions are not a replacement for Illustrator’s image trace feature, they are meant for designers who do not have access to Adobe Illustrator but have a requirement to convert images into vector shapes.
Stipplr Actions are very similar to Adobe Shape CC in that they both generate a vector shape result from raster data.
To avoid the unnecessary process of cleaning up a scanned image and removing the penciller’s visible construction lines, as well as other artifacts from the sketch I’d like to reveal a few processes I use. The following procedure takes place prior to scanning my artwork in order to avoid a lengthy clean up process within Photoshop later.
My favorite method for creating sketches is to use a non-photo pencil. A non-photo, or non-repro, pencil is one with a shade of blue that does not appear when photocopied or photographed — this process is not used often today due to the proliferation of cheap scanning equipment. However, the concept of the non-photo pencil is still very useful, we might not be taking a photo of our artwork but we can easily remove the blue from our scanned image within Photoshop without breaking a sweat.
Here is the sketch without the ink lines:
Obviously the non-photo pencil is easily detected by the scanner, however the reason for sketching in blue will become evident soon.
Here is the pencil sketch after being inked with a few felt tip markers. At this point we have a few options to get rid of the penciller’s lines which will help us dramatically reduce the amount of effort required to clean up the sketch in Photoshop…
The most obvious step to clean up the sketch is to use an eraser to simply remove all the sketch lines — I like using the Staedtler Rasoplast as it doesn’t scratch the paper leaving the surface of the paper fuzzy. This method is fairly standard and doesn’t require that you use a non-photo pencil at all, a standard carbon pencil will be just fine. Using an eraser is fast and doesn’t require any modifications once inside Photoshop.
The second option is to scan and open the sketch with the combined marker and non-photo pencil linework, directly into Photoshop and use the Hue/Saturation panel to set the Blues in the scan to full lightness.
The non-photo pencil sketch lines instantly disappear when the Blues are set to full lightness.
While this process is a few steps longer than simply erasing the linework prior to scanning you will avoid the potential to smudge the marker linework. Another potential side effect is causing the inked linework to lighten in certain areas where too much, or repeated, pressure was applied with the eraser. The inked linework would be uneven not only in the filled regions but the linework itself where lines might not be traced as cleanly as you had hoped. These changes lightened ares will also make working with the Levels harder when attempting to darken the image prior to running the Stipplr image trace.
Scan And Import
Once the sketch is scanned and imported into Photoshop we need to adjust the levels to even out the marker effect, attemping to run an image trace on the image as it exists would create thinned out vector shape.
Make Linework As Dark As Possible
Solid black linework is desireable for the AUTOTRACE and SIMPLETRACE Actions when tracing inked or very dark pencil linework because we are looking for a vector shape equivalent of our linework drawing. This process is not required for the majority of the Actions on this site which are made to be used on color photographs, indeed it is not recommended to run AUTOTRACE or SIMPLETRACE on photos as the results will likely be less than desirable.
The following is an example of the marker pattern we should try to minimize prior to running the AUTOTRACE001 Stipplr Action — this sample is one of the bubbles in the lower left of the Spongebob illustration.
Below is an example of what Stipplr would have output if the linework was not adjusted to reduce the marker patterns in your sketch prior to processing. On the left we can clearly see that Stipplr was not able to create a solid shape, the marker pattern and variations in keyline intensity caused the Action to trace the marker pattern as well as completely miss the first few millimeters around the entire shape.
On the right, where the Levels were corrected to flatten out the marker lines, we can see that the vector shape result is nearly indistinguishable from the the raster shape above.
To even out the marker linework in Spongebob’s water bubbles and linework simply open Photoshop’s Levels modal and slide the Shadows to 100.
Not All Paper, Markers And Scanners Are Created Equally
A Photoshop Shadow adjustment of 100 works great for me but may require more or less depending on the combination of materials you are using for your sketches.
And here is the marker sketch fully prepared to be auto traced, all signs of marker strokes within the bubbles and the linework has been completely removed.
A Note About White Fill And Backgrounds
Stipplr Actions are designed to ignore white — you do not need to prepare the image any further as white will not be converted into vector shapes.
Run Image Trace
Time for some vector magic!
Image tracing your sketch is now just a few clicks away:
- With the source image layer selected in the Photoshop Layers panel, ensure that the layer is visible.
- Expand the AUTOTRACE001 Stipplr Action in the Actions panel and highlight the script.
- Click the playback button.
Processing Is Fast
The bulk of Stipplr Actions take less than 1 minute to process source images, however, in cases where the document size exceeds 4K the process time can increase to 3-4 minutes.
Within seconds of running the AUTOTRACE001 Action script your vector shape is placed on the layer above the source image. Only the selected source image is traced regardless of the visibility of other groups and layers which may exist in your PSD.
- The new vector shape Smart Object layer is named with the Stipplr Action that was used to perform the trace, as is the containing group.
- As the thumbnail preview above, and the image below reveals, the vector shape is fully transparent anywhere white was found in the source image layer.
Here is the final vector shape result:
Stipplr Presets Are Baked In
There are no options for Stipplr Actions because each Stipplr Action is a preset with very specific parameters that are designed to create an expected result. AUTOTRACE001 generates results which closely resemble the original raster linework, imperfections and jittery linework in the original sketch will also be present in the vector shape results. For smoother linework try AUTOTRACE002 or SIMPLETRACE001 and SIMPLETRACE002 which offer more control over how tightly the linework should match the original source.
Compare Adobe Shape Vector Result
And finally, here is a comparison between the original source sketch image and the resulting Adobe shape vector layer generated by the Stipplr Action.
Stipplr’s involvement in quickly providing an editable vector shape layer is now over.
Cleaning up the results, colouring and composition of the vector shape goes beyond the task Stipplr Actions were designed to provide and therefore is entirely left to the designer.
Coloring The Result…
An optional followup article located here walks you through the process of manually coloring vector shapes.Download FREE Trial