Chaining Image Generations Is a Pipeline Bug: Measuring Drift Across Four Rendering Stages

Description and use

Chaining image generations causes drift that becomes indistinguishable from intended details. Re-generating each step from the original image stops the drift.

Problem

Chaining image generation steps causes drift, where errors introduced early propagate and become indistinguishable from intended outputs in later stages.

Outcome

Chaining causes compounding drift; refactoring to generate each finish directly from the base line art stops drift and yields more consistent results.

Workflow

• 1. Prepare a base image and set fixed seed, model, and instruction.
• 2. Run line art generation.
• 3. Pass line art to grayscale stage.
• 4. Pass grayscale to flat colors stage.
• 5. Pass flat colors to final render stage.
• 6. Measure drift by comparing edge maps and pixel statistics across stages.
• 7. Refactor by generating each finish directly from the base line art instead of chaining.

Evidence

Chaining generations is convenient and lossy. Every pass rewrites the entire image, so anything that survives does so by being redrawn the same way.

Source

The chained final render preserved everything and advanced almost nothing.

Source