dsh-plugin-doubao-image
v0.1.1
Published
Image generation through the locally installed Doubao desktop app, driven over the Chrome DevTools Protocol — no API key, no headless browser.
Maintainers
jayanttangReadme
doubao-image — generate images with the local Doubao app
面向：使用者 · 状态：stable · 最近核对：2026-09-20
Registers one tool, generate_image, that drives the locally installed and
logged-in Doubao (豆包) desktop app to produce a picture, saves the
full-resolution file, and sends it into the conversation.
plugins/doubao-image/
├── package.json # type: module, dsh.bundle.patch, exports
├── cordis.patch.yml # bundle patch: the loader row
├── lib/
│ ├── index.js # cordis plugin: the generate_image tool
│ ├── doubao.mjs # app launch, prompt submission, result harvest
│ ├── cdp.mjs # dependency-free Chrome DevTools Protocol client
│ ├── watermark.mjs # removes Doubao's own overlay, with a self-check
│ ├── image.mjs # minimal PNG codec + raster helpers
│ └── generate.mjs # CLI driver, for testing without spending a model turn
└── test/ # node --test (no DSH, no app, no network)Install
# from npm
dsh plugin --profile web add dsh-plugin-doubao-image
# or from the repository root — the leading ./ matters: DSH anchors relative specs
# against your current directory, otherwise pnpm would resolve it inside the profile
dsh plugin --profile web add ./plugins/doubao-imageThen restart DSH (or reload the profile). The tool appears as generate_image.
Use
# exercise the whole path without going through the model
node plugins/doubao-image/lib/generate.mjs \
--prompt "一只戴黄铜护目镜的橘猫，坐在双翼飞机驾驶舱里" \
--style "黏土质感 C4D 渲染，暖色夕阳光" \
--out ~/Pictures/doubaoThe tool takes prompt (required) plus style, composition, aspect,
negative, count, dir, and reuseCurrentChat.
How it works, and why it is built this way
Doubao ships a full Chromium (Contents/Helpers/Doubao Browser.app), and its
launcher forwards unknown flags, so starting it with --remote-debugging-port
yields a real CDP endpoint. That is the whole reason this works without the
macOS Accessibility permission that osascript would need — which matters,
because that permission is not granted on this machine.
The findings each step depends on, all established by probing the running app:
| Step | What is actually true |
| --- | --- |
| Launch | Doubao holds a singleton lock. A normally-launched instance never opens the debug port, and launching again just forwards to it. The app must therefore be quit and restarted — the first call costs ~10–40 s. |
| Attach | doubao-chat is the real 1200×800 window. doubao-launcher is a 400×600 sidebar that also accepts prompts and renders results at 90 px, and doubao-chat is additionally served as an empty <html>hello</html> shell. Identification uses live window size plus the presence of the editor, never the URL alone. |
| Type | The box is div.tiptap.ProseMirror[contenteditable=true]. execCommand('insertText') goes through the same beforeinput path a keystroke does, so the app's own state and send button update. Assigning innerText would not. |
| Detect | The status sentence 「已生成 N 张候选图」 is the completion signal, not the image count — the grid mounts placeholders before the renders arrive. |
| Harvest | The picture in the grid is a cpreview_wm1 render behind an overlay, and its full-size sibling <img> is a bare data:image/svg+xml placeholder with no pixels, so the bytes cannot be read from the grid. Instead the tool clicks each thumbnail to open the image viewer and uses the app's own [data-testid=edit_image_download_button], which writes the file to ~/Downloads; the tool then moves it to dir. |
dsh-doctor-style checks live in the unit tests: the output schema must stay in
sync with execute, because a tool that returns a value without a declared
schema is refused at registration and takes the whole plugin tree — and every
DSH boot, DSH.app included — down with it.
The watermark
Doubao stamps 「豆包AI生成」 into the bottom-right of every saved picture. It is an overlay the app composites on, not part of the artwork, which is what makes removal a solved problem instead of an inpainting guess. All of this was measured, not assumed:
| Property | Measurement |
| --- | --- |
| Position | Anchored to the bottom-right corner; a glyph mask from one image correlates with an unrelated image's corner at NCC 0.949 (inverse control −0.949, exactly symmetric) |
| Scale | Proportional to the image's short side, not its width: 2048²→321×69 box, 1365×2048→214×46 box, both giving width/short ≈ 0.1567. Verified on a second sample per shape |
| Blend | Plain alpha composite C = a·W + (1−a)·B, fitted at a = 0.638, W = 234.4, RMS residual 6.3/255 |
| Soft edge | Glyph interiors measure a = 0.63 while the antialiased rim ramps to 0 — which is why a hard 0/1 mask left a visible outline |
Removal inverts the composite per pixel, and estimates the artwork behind the mark by coarse-grid interpolation that excludes masked pixels. The output PNG is encoded losslessly (round-trip delta verified 0).
Self-check. The verifyOnFlat helper turns "does it look clean?" into a
number: on a flat-background sample the artwork behind the mark is a constant, so
any residual offset inside the glyph area is the watermark that survived.
Measured on a flat 2048² sample: residual 46.3 → 0.0 (100% removed). On a
photograph the same metric would be meaningless, so it detects a non-flat frame
(background IQR > 8) and says so instead of printing a flattering zero.
Scope. This targets this one overlay, at this one anchor, with this one calibrated blend. It is not a general watermark remover. It exists for internal reference material — animation reference, storyboards, internal review. Doubao's official API (Volcengine Ark) returns images with no watermark at all, and that is the right channel for anything published or commercial.
Known limitations
- Generation consumes the user's Doubao quota (the app reports 「本次生成将 消耗每日免费额度」). Exactly one generation is issued per call; if the plugin cannot confirm a submission it stops rather than retrying, because a blind retry is what once produced duplicate generations.
- The app window is closed and reopened on the first call, and Doubao must stay running-and-instrumented for the harvest to complete.
- The harvest depends on Doubao's own UI markup (
image-box-grid,edit_image_download_button). A Doubao redesign breaks it; the selector surface is deliberately kept to those two names. - The watermark pass only re-encodes PNG. Other formats are saved exactly as downloaded rather than silently recompressed.