batch generation

[nihui]

No description provided.

[Copilot]

Pull request overview

This pull request adds batch generation capability to the z-image-ncnn-vulkan tool, allowing users to generate multiple images in a single run with different random seeds. The implementation processes images sequentially using a single model load, where each image in the batch gets a unique seed (seed + batch_index).

Changes:

• Added -b batch-size command-line option with validation (must be > 0)
• Modified image generation to use a vector of latents instead of a single latent
• Restructured the main loop to process each batch item sequentially
• Implemented automatic filename generation for batch mode (filename-0.ext, filename-1.ext, etc.)

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 6 comments.

File	Description
src/main.cpp	Added batch processing logic, CLI argument parsing for batch size, latent vector handling, and batch-aware progress messages and file naming
README.md	Updated usage documentation to include the new -b batch-size option

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.