diff --git a/.gitignore b/.gitignore
index a36d949..4a03588 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,4 @@
 node_modules
 package.json
 package-lock.json
+libopenjpeg*
\ No newline at end of file
diff --git a/demo/serviceWorker/index.js b/demo/serviceWorker/index.js
index 934ba5f..f6c242e 100644
--- a/demo/serviceWorker/index.js
+++ b/demo/serviceWorker/index.js
@@ -282,7 +282,6 @@ imgBox.addServiceWorker = async () => {
     navigator.serviceWorker.register(`../../imagebox3.js?tileServerPathSuffix=${tileServerPathSuffix}`)
 		.catch((error) => {
       console.log('Service worker registration failed', error)
-      reject(error)
 		})
     await navigator.serviceWorker.ready
 	}
diff --git a/imagebox3.js b/imagebox3.js
index e0661cb..95f06bc 100644
--- a/imagebox3.js
+++ b/imagebox3.js
@@ -218,7 +218,7 @@ var imagebox3 = (() => {
 
     try {
       const headers = cache ? { headers: {'Cache-Control': "no-cache, no-store"}} : {}
-      tiff[imageID].pyramid = tiff[imageID].pyramid || ( await GeoTIFF.fromUrl(imageID, headers) )
+      tiff[imageID].pyramid = tiff[imageID].pyramid || ( imageID instanceof File ? await GeoTIFF.fromBlob(imageID) : await GeoTIFF.fromUrl(imageID, headers) )
 
       const imageCount = await tiff[imageID].pyramid.getImageCount()
       if (tiff[imageID].pyramid.loadedCount !== imageCount) {
diff --git a/imagebox3.mjs b/imagebox3.mjs
index 57eaf69..b11d3c8 100644
--- a/imagebox3.mjs
+++ b/imagebox3.mjs
@@ -1,6 +1,6 @@
 // DO NOT USE THIS FILE IN SERVICE WORKERS. USE imagebox3.js INSTEAD.
 
-import { fromUrl, Pool } from "https://cdn.jsdelivr.net/npm/geotiff@2.0.7/+esm"
+import { fromBlob, fromUrl, Pool } from "https://cdn.jsdelivr.net/npm/geotiff@2.0.7/+esm"
 
 const imagebox3 = (() => {
 
@@ -197,7 +197,7 @@ const imagebox3 = (() => {
 
     try {
       const headers = cache ? { headers: {'Cache-Control': "no-cache, no-store"}} : {}
-      tiff[imageID].pyramid = tiff[imageID].pyramid || ( await fromUrl(imageID, headers) )
+      tiff[imageID].pyramid = tiff[imageID].pyramid || ( imageID instanceof File ? await fromBlob(imageID) : await fromUrl(imageID, headers) )
 
       const imageCount = await tiff[imageID].pyramid.getImageCount()
       if (tiff[imageID].pyramid.loadedCount !== imageCount) {