emaarco Skill: svg-to-png
Renders an SVG to a PNG locally using resvg — a Rust SVG rendering engine. Everything runs on the machine: no uploading the file to a web converter and downloading the result.
What resvg does: SVG → PNG only. It does not read raster images (no PNG → SVG tracing) and it does not emit JPG/WebP/PDF directly. For a non-PNG raster target, render to PNG first, then convert the PNG (see step 5).
Steps
1. Check the precondition
resvg must be on PATH:
resvg --version
If it is missing, install it (macOS):
brew install resvg
For other platforms it ships via cargo install resvg or as a prebuilt binary from the releases page. Do not proceed until resvg --version succeeds.
2. Identify the source file
If the user has not given a .svg path, ask which file to render. Confirm the input is actually an SVG — resvg cannot rasterize a PNG or JPG into an SVG.
3. Determine the output path
Default: the same directory and basename as the source, with a .png extension (diagram.svg → diagram.png). If that would overwrite an existing file, mention it before running. Ask if the intended location is unclear.
4. Render
Basic conversion:
resvg input.svg output.png
Reach for these options when the request calls for them (see resvg --help for the full list):
| Need | Flag | Example |
|---|---|---|
| Higher resolution | -z, --zoom FACTOR |
resvg -z 2 in.svg out.png (2× pixel dimensions) |
| Exact pixel width/height | -w / -h |
resvg -w 1024 in.svg out.png |
| Print/DPI scaling | --dpi DPI |
resvg --dpi 300 in.svg out.png |
| Solid backdrop (SVGs are transparent by default) | --background COLOR |
resvg --background white in.svg out.png |
| Crop to the drawing's tight bounds | --export-area-drawing |
resvg --export-area-drawing in.svg out.png |
| Export one element by id | --export-id ID |
resvg --export-id logo in.svg out.png |
Prefer -z/--dpi for crisp output over letting a downstream tool upscale the PNG.
Fonts: if the SVG contains text and glyphs render wrong or missing, the font is not in the system database. Point resvg at it with --use-font-file <path> or --use-fonts-dir <dir>, or run resvg --list-fonts to see what loaded.
5. (Optional) Convert the PNG to another raster format
resvg only writes PNG. For a different raster target, convert the rendered PNG with the macOS built-in sips — no extra install:
sips -s format jpeg output.png --out output.jpg # or: png, tiff, gif, bmp
sips has no WebP encoder; use cwebp output.png -o output.webp (brew install webp) if WebP is required. Flatten transparency before JPEG (--background white in step 4), since JPEG has no alpha channel.
6. Confirm
Report the output path and the resolved pixel dimensions, and confirm the conversion succeeded. Batch requests: loop over the inputs, reusing the same flags for each.