Linearity Curve's Auto Trace feature enables you to convert any raster image (JPEG or PNG) into vector artwork.
With this feature, you can create a completely new image based on an existing artwork or a reference photo without drawing the vector shapes by hand. You can trace a sketch you have drawn on paper into vector artwork and scale it as much as you like.
The Auto Trace panel is a content-aware menu, which means that it will be only visible when an image is selected. The panel will appear automatically at the top of the Style Tab.
In the Auto Trace Panel, you have three Auto Trace modes available
- A – The Photography Mode, for turning your photos into painting-like portraits.
- B – The Sketch Mode to convert your sketches into vectors in seconds.
- C - The Illustration Mode to vectorize your illustrations.
Press the Mode button (2) to select which Auto Trace mode you want to use to trace your image.
The content-aware Auto Trace menu (3) pops up inside the Quick Actions Bar, as soon as you select an image.
Auto Trace analyzes your image with the aid of the CoreML Machine Learning.
When the Sketch Mode is selected (1), you will have two sliders available that will set the following parameters:
- A – Complexity. A lower value will group smaller areas and vice versa.
- B – Contrast This slider defines a threshold at which numeric value a color will be converted into black or white. Higher slider values will interpret more colors as black and lower slider values will interpret more colors as white.
Once you have adjusted these two settings, tap the Auto Trace Button and wait a few seconds until the process is finished.
Below, you can see examples of different parameter settings:
The Sketch Mode generates only a black and white vector output.
If you want to trace a low contrast image with the Sketch Mode, the contrast setting plays a crucial role in the quality of the final result.
When the Illustration Mode is selected (1), you will have a menu with a slider, three buttons, and two toggles available that control the following parameters:
- A – Min Path Size. Here you can define the threshold for your path size. The higher the set value, the longer the path between points will be. The lower the set value, the shorter the distance between points will be. The shorter the path distance between points, the higher the resulting level of detail will be. The Min Path Size of the Illustration Mode is set to 10 by default.
- B – Level of Details. This slider defines the level of detail that will be kept in the resulting traced vector image. You can choose between the levels Low, Regular and High. Low will reproduce a traced image with significantly less detail, whereas regular to high will include more detail from the original image in the final tracing result.
- C – Simplify Path → If you activate Simplify Path, fewer nodes will be created. The mode is best suited for tracing motifs with simple and uncomplicated lines. If the mode is activated, the tracing process will take less time.
- D – Keep Source Image. If you activate Keep Source Image, the original raster image will be kept and organized below the traced vector image in the layer hierarchy. The original raster image will be grouped with the traced vector image in the Layers Tab.
Once you have adjusted the settings mentioned above, tap the Auto Trace Button and wait a few seconds until the tracing process is finished.
The Illustration Mode is only applicable on an A12 processor or its corresponding devices, such as the iPhone XR / iPad Air 3rd gen and newer, and M1 MacBooks or higher.
Below, you can see examples of different parameter settings:
[object Object]0. For complex illustrations, we recommend you set the Min Path Size values around 10-20% and set the Level of Detail to High. (For the example below we set the Min Path Size to 12%)
Artwork by Kelly Llanos
[object Object]0. You can use the Illustration Mode for flat illustrations. In this case, we recommend you to reduce the Min Path Size values to 0% and set the Level of Detail to Low.
[object Object]0. You can use the Illustration Mode for your painting illustrations too, as the example below. In this case, we set the Min Path Size value to 10% and the Level of Detail to High as the artwork contains several details. If there’s any gradient, the Auto Trace will merge all gradient into one color. You can check the results by activating the Outline Mode.
If you want to learn more about the development process behind the new Illustration Mode feature, read the Interview with our developer Marko
The Photography Panel contains two sliders, which allow you to set the number of paths and the path size:
- A – Complexity. This slider adjusts how many paths your vectorized image will have. By moving your finger along the slider, you can adjust the percentage of paths your vectorized image will contain. A lower value will give you a more abstract result, and a higher value will result in a more detailed path.
- B – Minimum Path Size. This slider sets the threshold for your path size. A higher value creates longer paths between points, resulting in a less detailed image, a lower value will generate shorter paths between points, producing a greater level of detail.
Once you have adjusted these two settings, tap the Auto Trace Button (2) and wait a few seconds.
⚠️ Please note that the Auto Trace feature does not support RGBA images containing an 8-bit Alpha Channel. Auto Trace interprets 8-bit Alpha Channel pixels as black instead of white.
In the Auto Trace panel you find also three toggles that help you improve your workflow and obtain optimal tracing results. These new toggles are Simplify (1), Ignore White (2), and Keep Source Image (3).
Auto Trace will create vector shapes with fewer nodes if you activate the toggle Simplify. This mode is optimal for tracing an image with simple, uncomplicated shapes. If you activate the simplify mode, the time required for the tracing process will be significantly reduced.
When you activate the Sketch Mode in Auto Trace, you then have the option to toggle the Ignore White feature on and off. With the new Ignore White feature, you can define if Auto Trace creates vector shapes out of white image areas or not. When Ignore White is turned on while in Sketch Mode, all the white areas of the source image will be erased.
If you trace an image with the Ignore White toggle turned on , the tracing process results are shapes organized as compound paths. This means that any path-related editing will affect the entire compound path structure. You can create a compound path from two or more open or closed paths. When you create a compound path, all of the originally selected paths are converted to subpaths of a new compound path. The selected paths inherit the stroke and fill settings of the object the farthest back in the stacking order. If you want to separate the compound paths, select the paths and tap the Separate icon button in the Path section.
When Ignore White is turned off , the resulting paths from the tracing process will be organized as a group, visible inside the Layers Tab.
Keep Source Image
If you activate Keep Source Image , the original image will be kept after the tracing process is finished. The original image is organized below the newly traced image in the layer hierarchy. Both layers, the traced image, and the original image are grouped in the Layers Tab.
Once your image has been transformed into vector shapes, you can edit the paths afterward.
⚠️ The Auto Trace feature is a destructive operation, meaning that once you have converted the image into vectors, you can no longer access or adjust the tracing options. The only option to revert the changes is by undoing the operation.
To edit your traced image, you can either add or remove nodes using the Node Tool, or you can go to the Path section and adjust the vectorized shapes by tapping the Delete Nodes button.