Images

{
  "worksheets": [
    {
      "name": "Images",
      "rows": [{ "cells": [{ "value": "Label" }, { "value": "Data" }] }],
      "images": [
        {
          "data": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNkYAAAAAYAAjCB0C8AAAAASUVORK5CYII=",
          "type": "png",
          "col": 3,
          "row": 1
        }
      ]
    }
  ]
}

import { readFileSync } from "node:fs";
import { generateWorkbook } from "@office-open/xlsx";

const buffer = await generateWorkbook({
  worksheets: [
    {
      name: "Images",
      rows: [{ cells: [{ value: "Label" }, { value: "Data" }] }],
      images: [
        {
          data: readFileSync("./photo.png"),
          type: "png",
          col: 3, // 1-based column (D column)
          row: 1, // 1-based row
        },
      ],
    },
  ],
});

{
  "worksheets": [
    {
      "name": "Gallery",
      "rows": [{ "cells": [{ "value": "Photos" }] }],
      "images": [
        {
          "data": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNkYAAAAAYAAjCB0C8AAAAASUVORK5CYII=",
          "type": "png",
          "col": 2,
          "row": 2
        },
        {
          "data": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNkYAAAAAYAAjCB0C8AAAAASUVORK5CYII=",
          "type": "jpg",
          "col": 5,
          "row": 2
        }
      ]
    }
  ]
}

images: [
  { data: pngData, type: "png", col: 2, row: 2 },
  { data: jpgData, type: "jpg", col: 5, row: 2 },
],