Bitmap Logo Vectorization: Principles and Applicability Boundaries of PNG/JPG to SVG Conversion

For vectorization in VTracer's color layered mode, the first step is to cluster the pixels of the input bitmap by color, grouping pixels with the same hue and lightness into the same color layer.

After clustering is complete, the contour of each color layer is fitted into a quadratic Bezier path. Different color layers are output as an editable SVG file in the original stacking order, preserving the layered structure of the original Logo.

The output quality of vector tracing is strongly correlated with the content type of the input image. Images with clear edges, a limited number of color blocks, and no continuous gradients can be stably clustered into a small number of color layers, resulting in smooth SVG paths and controllable node counts. Such images include software Logos, application icons, silhouette graphics, and black-and-white text.

Photos and gradient illustrations are not suitable for vectorization: continuous tone areas are forcibly split into dozens of color layers, and the generated SVG is larger in size than the original bitmap and visually presents color banding artifacts. This type of content should be retained in bitmap format, and use resizing or compression tools when downsizing, instead of vector tracing.

Bitmap Logos obtained from scanning or screenshots often have isolated small patches of noise pixels. These patches will generate extra tiny paths after vectorization.

The filterSpeckle parameter filters noise through a pixel area threshold. A higher value corresponds to a larger area threshold for filtered small patches, resulting in fewer redundant paths in the output SVG and a smaller file size.

Direct bitmap upscaling relies on interpolation algorithms, which generate new pixels by calculating from existing pixels. When the magnification exceeds 3 times, edges will become blurred or jagged, which cannot meet the requirements of printing output.

The SVG obtained from vectorization stores Bezier path coordinates. No matter how many times it is scaled up, the path edges remain consistently smooth. The path description can be directly parsed by printing equipment, and the output accuracy meets printing requirements.

In Figma desktop version 2023 and above, simply drag and drop the output SVG file onto the canvas, right-click and select Ungroup to split the different color layers, and modify the color and shape of each path individually.

In Adobe Illustrator CS6 and above versions, open the output SVG file directly. You can view the split color layers in the layers panel, and select the corresponding path to adjust the stroke or fill properties.