n8n - 💡(How to fix) Fix Edit Image composite fails with "Stream yields empty buffer" on valid Gemini-generated PNG in n8n 2.19.5 [3 comments, 4 participants]

Describe the problem/error/question

The Edit Image node fails during composite operation with:

Stream yields empty buffer

The input image appears to be a valid PNG generated by Gemini image generation API. The binary file exists and can be viewed/downloaded in n8n UI.

This happens when compositing a logo image onto the generated PNG.

Workflow sequence:

1. Gemini API returns inline base64 image data
2. Convert to File converts it to binary property data
3. Google Drive node downloads a logo into binary property logo
4. Edit Image1 resizes the logo successfully
5. Edit Image composite fails when compositing logo onto data

The failure seems to come from the underlying [email protected] dependency used by n8n's Edit Image node.

I also tried stripping PNG metadata chunks such as iCCP, sRGB, gAMA, cHRM, tEXt, iTXt, and zTXt before the composite step. The PNG remained valid, but the composite node still failed with the same error.

Expected behavior:

The Edit Image node should either:

• successfully composite a valid PNG image, or
• return a more specific image decoding/composite error explaining which input binary property or format is unsupported.

Actual behavior:

The node fails with a generic Stream yields empty buffer error.

What is the error message (if any)?

{
  "errorMessage": "Stream yields empty buffer",
  "errorDetails": {},
  "n8nDetails": {
    "n8nVersion": "2.19.5 (Self Hosted)",
    "binaryDataMode": "filesystem",
    "stackTrace": [
      "Error: Stream yields empty buffer",
      "    at Socket.<anonymous> (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/[email protected]/node_modules/gm/lib/command.js:56:21)",
      "    at Socket.emit (node:events:520:35)",
      "    at endReadableNT (node:internal/streams/readable:1729:12)",
      "    at processTicksAndRejections (node:internal/process/task_queues:90:21)"
    ]
  }
}

<img width="1068" height="1106" alt="Image" src="https://github.com/user-attachments/assets/0221a805-5fe1-4987-a8eb-f11b755012f9" />

<img width="1068" height="1096" alt="Image" src="https://github.com/user-attachments/assets/603586ca-f2a2-47e2-b255-04c66a81325d" />