diff --git a/src/agents/pi-embedded-runner/run/images.ts b/src/agents/pi-embedded-runner/run/images.ts
index f7de8b734..dad5805bf 100644
--- a/src/agents/pi-embedded-runner/run/images.ts
+++ b/src/agents/pi-embedded-runner/run/images.ts
@@ -163,6 +163,8 @@ export async function loadImageFromRef(
     // For file paths, resolve relative to the appropriate root:
     // - When sandbox is enabled, resolve relative to sandboxRoot for security
     // - Otherwise, resolve relative to workspaceDir
+    // Note: ref.resolved may already be absolute (e.g., after ~ expansion in detectImageReferences),
+    // in which case we skip relative resolution.
     if (ref.type === "path" && !path.isAbsolute(targetPath)) {
       const resolveRoot = options?.sandboxRoot ?? workspaceDir;
       targetPath = path.resolve(resolveRoot, targetPath);
diff --git a/src/web/media.ts b/src/web/media.ts
index 50dce16d1..1d9bdceab 100644
--- a/src/web/media.ts
+++ b/src/web/media.ts
@@ -1,5 +1,6 @@
 import fs from "node:fs/promises";
 import path from "node:path";
+import { fileURLToPath } from "node:url";
 
 import { logVerbose, shouldLogVerbose } from "../globals.js";
 import { type MediaKind, maxBytesForKind, mediaKindFromMime } from "../media/constants.js";
@@ -24,8 +25,9 @@ async function loadWebMediaInternal(
   options: WebMediaOptions = {},
 ): Promise<WebMediaResult> {
   const { maxBytes, optimizeImages = true } = options;
+  // Use fileURLToPath for proper handling of file:// URLs (handles file://localhost/path, etc.)
   if (mediaUrl.startsWith("file://")) {
-    mediaUrl = mediaUrl.replace("file://", "");
+    mediaUrl = fileURLToPath(mediaUrl);
   }
 
   const optimizeAndClampImage = async (buffer: Buffer, cap: number) => {
@@ -57,7 +59,7 @@ async function loadWebMediaInternal(
     kind: MediaKind;
     fileName?: string;
   }): Promise<WebMediaResult> => {
-    const cap = Math.min(maxBytes ?? maxBytesForKind(params.kind), maxBytesForKind(params.kind));
+    const cap = maxBytes !== undefined ? Math.min(maxBytes, maxBytesForKind(params.kind)) : maxBytesForKind(params.kind);
     if (params.kind === "image") {
       const isGif = params.contentType === "image/gif";
       if (isGif || !optimizeImages) {