byted-tos-image-process

Documents

Inspects and transforms images stored in Volcengine TOS: read metadata, convert formats, resize, draw points and lines, perform zoom-style resize plus crop, add visible text or image watermarks, embed blind watermarks, and AI-powered image understanding (VLM). Use this skill when the user needs to get image dimensions or format info, convert between JPEG/PNG/WebP, resize or crop images, annotate images with markers or boxes, add watermarks, extract blind watermarks, describe image content, perform OCR, detect faces, or answer visual questions — even if they don't explicitly mention 'image processing' or 'TOS'.

QUICK START

How to use this skill

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Prompt to paste

I want to install this Agent Skill for this project in Codex.

Source SKILL.md: https://github.com/bytedance/agentkit-samples/blob/HEAD/skills/byted-tos-image-process/SKILL.md

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Copying this prompt does not install or run the skill. Review third-party files before use. Codex skill guide

Volcengine TOS Image Process

Inspect and transform images stored in Volcengine TOS — metadata, format conversion, resize, watermark, blind watermark, and AI-powered image understanding.

Setup (once per environment)

Install dependencies on first use:

cd {baseDir}
pip install -r {baseDir}/requirements.txt

Then run scripts with Python 3.7+:

python3 {baseDir}/scripts/<script>.py <args>

If you see a ModuleNotFoundError for tos, reinstall dependencies.

Environment Variables

This skill relies on the TOS identity declared in the metadata block. Common runtime variables are:

Environment Variable	Required	Description
`TOS_ACCESS_KEY`	Yes	TOS access key ID
`TOS_SECRET_KEY`	Yes	TOS secret access key
`TOS_ENDPOINT`	Yes	TOS endpoint URL
`TOS_REGION`	Yes	TOS region
`TOS_BUCKET`	Yes	Source bucket that stores the image
`TOS_OBJECT_KEY`	No	Source object key of the image. Can be overridden with `--key`
`TOS_SECURITY_TOKEN`	No	STS session token when using temporary credentials
`TOS_SAVEAS_BUCKET`	No	Default target bucket for saving processed results
`TOS_SAVEAS_OBJECT_PREFIX`	No	Default key prefix for saving processed results

Quick start (common tasks)

# Read image metadata
python3 {baseDir}/scripts/image_info.py --key photo.jpg

# Convert to WebP
python3 {baseDir}/scripts/image_format.py --key photo.jpg --f webp --output converted.webp

# Resize to width 500
python3 {baseDir}/scripts/image_resize.py --key photo.jpg --w 500 --output resized.jpg

# Draw points and connecting lines
python3 {baseDir}/scripts/image_draw.py --key photo.jpg \
  --points 50x50-200x120-320x220 --line --color FF0000 --output draw.jpg

# Zoom by resize + crop
python3 {baseDir}/scripts/image_zoom.py --key photo.jpg \
  --resize-w 1200 --crop-w 500 --crop-h 400 --gravity center --output zoom.jpg

# Add visible text watermark
python3 {baseDir}/scripts/image_watermark.py --key photo.jpg \
  --text "My Brand" --font fangzhengshusong --color FF0000 --size 72 \
  --gravity center --output watermarked.jpg

# Embed blind watermark (requires ≥512×512 image and account permission)
python3 {baseDir}/scripts/image_blindwatermark.py --key photo.jpg \
  --kv text=HelloBlind --output blind.jpg

# Run a custom process string
python3 {baseDir}/scripts/image_process.py --key photo.jpg \
  --process "image/resize,w_300,h_300,m_fill" --output filled.jpg

# AI-powered image understanding (describe, OCR, face detection, etc.)
python3 {baseDir}/scripts/image_understanding.py --key photo.jpg \
  --prompt "Describe this image in detail"
python3 {baseDir}/scripts/image_understanding.py --key document.png \
  --prompt "识别图片中的所有文字内容"

Available scripts

Script	Purpose
`scripts/image_info.py`	Read image metadata (format, dimensions, size). Falls back to local parsing when TOS returns raw bytes.
`scripts/image_format.py`	Convert format (jpg, png, webp) with optional quality setting.
`scripts/image_resize.py`	Resize by width/height/mode.
`scripts/image_draw.py`	Draw points and optional connecting lines on an image with `image/draw`.
`scripts/image_zoom.py`	Build agent-friendly zoom results by chaining `image/resize` and `crop`.
`scripts/image_watermark.py`	Add visible text or image watermark with positioning, rotation, tiling, and opacity.
`scripts/image_blindwatermark.py`	Embed blind watermark. Requires account-level permission and image ≥512×512 px.
`scripts/image_process.py`	Pass any raw `image/...` process string.
`scripts/image_understanding.py`	AI-powered image understanding via VLM (doubao-seed-1.6-vision). Supports description, OCR, face detection, and visual Q&A through natural language prompts. Requires account whitelist.

All scripts support --key to override TOS_OBJECT_KEY, --output for local save, and --saveas-bucket/--saveas-object for TOS-to-TOS persistence. Most scripts also support --json for machine-readable output, and the process-building scripts support --dry-run to preview the resolved request. Run any script with -h for full usage.

Out of scope

Editing images with local desktop tooling outside TOS.
Video or document processing (use byted-tos-video-process or byted-tos-doc-process).
Non-TOS storage providers.

Rules

Authentication: Authentication is provided by the TOS identity declared in the metadata block above. Object selection can be overridden per script with --key.
Parameter source of truth: The exact process string syntax is defined by official Volcengine TOS documentation. When uncertain, check REFERENCE.md.
Watermark encoding: Text and font parameters in image/watermark require URL-safe Base64 encoding. The watermark script handles this automatically when you pass --text and --font.
Blind watermark constraints: The source image must be at least 512×512 pixels, and the account must have the blind watermark capability enabled. If the capability is missing, the script exits with [SKIP] (use --strict to fail hard).
Image understanding: Uses image/understanding with the doubao-seed-1.6-vision VLM model. The --prompt parameter is required. Supports description, OCR, face detection, and any visual Q&A task. Requires account whitelist. Response time is typically 10-60 seconds.
Language: Reply in the user's preferred language.