diff --git a/src/tools/look-at/image-converter.test.ts b/src/tools/look-at/image-converter.test.ts
new file mode 100644
index 00000000..37c9cdf2
--- /dev/null
+++ b/src/tools/look-at/image-converter.test.ts
@@ -0,0 +1,60 @@
+import { describe, expect, test, mock, beforeEach } from "bun:test"
+import { existsSync, mkdtempSync, writeFileSync, unlinkSync, rmSync } from "node:fs"
+import { tmpdir } from "node:os"
+import { join } from "node:path"
+
+const originalChildProcess = await import("node:child_process")
+
+const execFileSyncMock = mock((_command: string, _args: string[]) => "")
+const execSyncMock = mock(() => {
+  throw new Error("execSync should not be called")
+})
+
+mock.module("node:child_process", () => ({
+  ...originalChildProcess,
+  execFileSync: execFileSyncMock,
+  execSync: execSyncMock,
+}))
+
+const { convertImageToJpeg } = await import("./image-converter")
+
+describe("image-converter command execution safety", () => {
+  beforeEach(() => {
+    execFileSyncMock.mockReset()
+    execSyncMock.mockReset()
+  })
+
+  test("uses execFileSync with argument arrays for conversion commands", () => {
+    const testDir = mkdtempSync(join(tmpdir(), "img-converter-test-"))
+    const inputPath = join(testDir, "evil$(touch_pwn).heic")
+    writeFileSync(inputPath, "fake-heic-data")
+
+    execFileSyncMock.mockImplementation((command: string, args: string[]) => {
+      if (command === "sips") {
+        const outIndex = args.indexOf("--out")
+        const outputPath = outIndex >= 0 ? args[outIndex + 1] : undefined
+        if (outputPath) writeFileSync(outputPath, "jpeg")
+      } else if (command === "convert") {
+        writeFileSync(args[1], "jpeg")
+      }
+      return ""
+    })
+
+    const outputPath = convertImageToJpeg(inputPath, "image/heic")
+
+    expect(execSyncMock).not.toHaveBeenCalled()
+    expect(execFileSyncMock).toHaveBeenCalled()
+
+    const [firstCommand, firstArgs] = execFileSyncMock.mock.calls[0] as [string, string[]]
+    expect(typeof firstCommand).toBe("string")
+    expect(Array.isArray(firstArgs)).toBe(true)
+    expect(firstArgs).toContain(inputPath)
+    expect(firstArgs.join(" ")).not.toContain(`\"${inputPath}\"`)
+
+    expect(existsSync(outputPath)).toBe(true)
+
+    if (existsSync(outputPath)) unlinkSync(outputPath)
+    if (existsSync(inputPath)) unlinkSync(inputPath)
+    rmSync(testDir, { recursive: true, force: true })
+  })
+})
diff --git a/src/tools/look-at/image-converter.ts b/src/tools/look-at/image-converter.ts
new file mode 100644
index 00000000..e95237ba
--- /dev/null
+++ b/src/tools/look-at/image-converter.ts
@@ -0,0 +1,149 @@
+import { execFileSync } from "node:child_process"
+import { existsSync, mkdtempSync, unlinkSync, writeFileSync, readFileSync } from "node:fs"
+import { tmpdir } from "node:os"
+import { join } from "node:path"
+import { log } from "../../shared"
+
+const SUPPORTED_FORMATS = new Set([
+  "image/jpeg",
+  "image/png",
+  "image/webp",
+  "image/gif",
+  "image/bmp",
+  "image/tiff",
+])
+
+const UNSUPPORTED_FORMATS = new Set([
+  "image/heic",
+  "image/heif",
+  "image/x-canon-cr2",
+  "image/x-canon-crw",
+  "image/x-nikon-nef",
+  "image/x-nikon-nrw",
+  "image/x-sony-arw",
+  "image/x-sony-sr2",
+  "image/x-sony-srf",
+  "image/x-pentax-pef",
+  "image/x-olympus-orf",
+  "image/x-panasonic-raw",
+  "image/x-fuji-raf",
+  "image/x-adobe-dng",
+  "image/vnd.adobe.photoshop",
+  "image/x-photoshop",
+])
+
+export function needsConversion(mimeType: string): boolean {
+  if (SUPPORTED_FORMATS.has(mimeType)) {
+    return false
+  }
+  
+  if (UNSUPPORTED_FORMATS.has(mimeType)) {
+    return true
+  }
+  
+  return mimeType.startsWith("image/")
+}
+
+export function convertImageToJpeg(inputPath: string, mimeType: string): string {
+  if (!existsSync(inputPath)) {
+    throw new Error(`File not found: ${inputPath}`)
+  }
+
+  const tempDir = mkdtempSync(join(tmpdir(), "opencode-img-"))
+  const outputPath = join(tempDir, "converted.jpg")
+
+  log(`[image-converter] Converting ${mimeType} to JPEG: ${inputPath}`)
+
+  try {
+    if (process.platform === "darwin") {
+      try {
+        execFileSync("sips", ["-s", "format", "jpeg", inputPath, "--out", outputPath], {
+          stdio: "pipe",
+          encoding: "utf-8",
+        })
+        
+        if (existsSync(outputPath)) {
+          log(`[image-converter] Converted using sips: ${outputPath}`)
+          return outputPath
+        }
+      } catch (sipsError) {
+        log(`[image-converter] sips failed: ${sipsError}`)
+      }
+    }
+
+    try {
+      execFileSync("convert", [inputPath, outputPath], {
+        stdio: "pipe",
+        encoding: "utf-8",
+      })
+      
+      if (existsSync(outputPath)) {
+        log(`[image-converter] Converted using ImageMagick: ${outputPath}`)
+        return outputPath
+      }
+    } catch (convertError) {
+      log(`[image-converter] ImageMagick convert failed: ${convertError}`)
+    }
+
+    throw new Error(
+      `No image conversion tool available. Please install ImageMagick:\n` +
+      `  macOS: brew install imagemagick\n` +
+      `  Ubuntu/Debian: sudo apt install imagemagick\n` +
+      `  RHEL/CentOS: sudo yum install ImageMagick`
+    )
+  } catch (error) {
+    try {
+      if (existsSync(outputPath)) {
+        unlinkSync(outputPath)
+      }
+    } catch {}
+    
+    throw error
+  }
+}
+
+export function cleanupConvertedImage(filePath: string): void {
+  try {
+    if (existsSync(filePath)) {
+      unlinkSync(filePath)
+      log(`[image-converter] Cleaned up temporary file: ${filePath}`)
+    }
+  } catch (error) {
+    log(`[image-converter] Failed to cleanup ${filePath}: ${error}`)
+  }
+}
+
+export function convertBase64ImageToJpeg(
+  base64Data: string,
+  mimeType: string
+): { base64: string; tempFiles: string[] } {
+  const tempDir = mkdtempSync(join(tmpdir(), "opencode-b64-"))
+  const inputExt = mimeType.split("/")[1] || "bin"
+  const inputPath = join(tempDir, `input.${inputExt}`)
+  const tempFiles: string[] = [inputPath]
+
+  try {
+    const cleanBase64 = base64Data.replace(/^data:[^;]+;base64,/, "")
+    const buffer = Buffer.from(cleanBase64, "base64")
+    writeFileSync(inputPath, buffer)
+
+    log(`[image-converter] Converting Base64 ${mimeType} to JPEG`)
+    
+    const outputPath = convertImageToJpeg(inputPath, mimeType)
+    tempFiles.push(outputPath)
+
+    const convertedBuffer = readFileSync(outputPath)
+    const convertedBase64 = convertedBuffer.toString("base64")
+
+    log(`[image-converter] Base64 conversion successful`)
+    
+    return { base64: convertedBase64, tempFiles }
+  } catch (error) {
+    tempFiles.forEach(file => {
+      try {
+        if (existsSync(file)) unlinkSync(file)
+      } catch {}
+    })
+    throw error
+  }
+}
diff --git a/src/tools/look-at/mime-type-inference.test.ts b/src/tools/look-at/mime-type-inference.test.ts
new file mode 100644
index 00000000..69ac6e6b
--- /dev/null
+++ b/src/tools/look-at/mime-type-inference.test.ts
@@ -0,0 +1,41 @@
+import { describe, expect, test } from "bun:test"
+import { extractBase64Data, inferMimeTypeFromBase64, inferMimeTypeFromFilePath } from "./mime-type-inference"
+
+describe("mime type inference", () => {
+  test("returns MIME from data URL prefix", () => {
+    const mime = inferMimeTypeFromBase64("data:image/heic;base64,AAAAGGZ0eXBoZWlj")
+    expect(mime).toBe("image/heic")
+  })
+
+  test("detects HEIC from raw base64 magic bytes", () => {
+    const heicHeader = Buffer.from("00000018667479706865696300000000", "hex").toString("base64")
+    const mime = inferMimeTypeFromBase64(heicHeader)
+    expect(mime).toBe("image/heic")
+  })
+
+  test("detects HEIF from raw base64 magic bytes", () => {
+    const heifHeader = Buffer.from("00000018667479706865696600000000", "hex").toString("base64")
+    const mime = inferMimeTypeFromBase64(heifHeader)
+    expect(mime).toBe("image/heif")
+  })
+
+  test("falls back to png when base64 signature is unknown", () => {
+    const mime = inferMimeTypeFromBase64("dW5rbm93biBiaW5hcnk=")
+    expect(mime).toBe("image/png")
+  })
+
+  test("infers heic from file extension", () => {
+    const mime = inferMimeTypeFromFilePath("/tmp/photo.HEIC")
+    expect(mime).toBe("image/heic")
+  })
+
+  test("extracts raw base64 data from data URL", () => {
+    const base64 = extractBase64Data("data:image/png;base64,abc123")
+    expect(base64).toBe("abc123")
+  })
+
+  test("extracts raw base64 data from data URL with extra parameters", () => {
+    const base64 = extractBase64Data("data:image/heic;name=clip.heic;base64,abc123")
+    expect(base64).toBe("abc123")
+  })
+})
diff --git a/src/tools/look-at/mime-type-inference.ts b/src/tools/look-at/mime-type-inference.ts
index 18954c46..0718259d 100644
--- a/src/tools/look-at/mime-type-inference.ts
+++ b/src/tools/look-at/mime-type-inference.ts
@@ -8,12 +8,18 @@ export function inferMimeTypeFromBase64(base64Data: string): string {
 
   try {
     const cleanData = base64Data.replace(/^data:[^;]+;base64,/, "")
-    const header = atob(cleanData.slice(0, 16))
+    const header = Buffer.from(cleanData.slice(0, 256), "base64").toString("binary")
 
     if (header.startsWith("\x89PNG")) return "image/png"
     if (header.startsWith("\xFF\xD8\xFF")) return "image/jpeg"
     if (header.startsWith("GIF8")) return "image/gif"
     if (header.startsWith("RIFF") && header.includes("WEBP")) return "image/webp"
+    if (header.includes("ftypheic") || header.includes("ftypheix") || header.includes("ftyphevc") || header.includes("ftyphevx")) {
+      return "image/heic"
+    }
+    if (header.includes("ftypheif") || header.includes("ftypmif1") || header.includes("ftypmsf1")) {
+      return "image/heif"
+    }
     if (header.startsWith("%PDF")) return "application/pdf"
   } catch {
     // invalid base64 - fall through
@@ -29,8 +35,25 @@ export function inferMimeTypeFromFilePath(filePath: string): string {
     ".jpeg": "image/jpeg",
     ".png": "image/png",
     ".webp": "image/webp",
+    ".gif": "image/gif",
+    ".bmp": "image/bmp",
+    ".tiff": "image/tiff",
+    ".tif": "image/tiff",
     ".heic": "image/heic",
     ".heif": "image/heif",
+    ".cr2": "image/x-canon-cr2",
+    ".crw": "image/x-canon-crw",
+    ".nef": "image/x-nikon-nef",
+    ".nrw": "image/x-nikon-nrw",
+    ".arw": "image/x-sony-arw",
+    ".sr2": "image/x-sony-sr2",
+    ".srf": "image/x-sony-srf",
+    ".pef": "image/x-pentax-pef",
+    ".orf": "image/x-olympus-orf",
+    ".raw": "image/x-panasonic-raw",
+    ".raf": "image/x-fuji-raf",
+    ".dng": "image/x-adobe-dng",
+    ".psd": "image/vnd.adobe.photoshop",
     ".mp4": "video/mp4",
     ".mpeg": "video/mpeg",
     ".mpg": "video/mpeg",
diff --git a/src/tools/look-at/tools.ts b/src/tools/look-at/tools.ts
index 0d5c1c0b..a4c67f05 100644
--- a/src/tools/look-at/tools.ts
+++ b/src/tools/look-at/tools.ts
@@ -13,6 +13,12 @@ import {
   inferMimeTypeFromFilePath,
 } from "./mime-type-inference"
 import { resolveMultimodalLookerAgentMetadata } from "./multimodal-agent-metadata"
+import {
+  needsConversion,
+  convertImageToJpeg,
+  convertBase64ImageToJpeg,
+  cleanupConvertedImage,
+} from "./image-converter"
 
 export { normalizeArgs, validateArgs } from "./look-at-arguments"
 
@@ -41,22 +47,58 @@ export function createLookAt(ctx: PluginInput): ToolDefinition {
 
       let mimeType: string
       let filePart: { type: "file"; mime: string; url: string; filename: string }
+      let tempFilePath: string | null = null
+      let tempFilesToCleanup: string[] = []
 
-      if (imageData) {
-        mimeType = inferMimeTypeFromBase64(imageData)
-        filePart = {
-          type: "file",
-          mime: mimeType,
-          url: `data:${mimeType};base64,${extractBase64Data(imageData)}`,
-          filename: `clipboard-image.${mimeType.split("/")[1] || "png"}`,
-        }
-      } else if (filePath) {
+      try {
+        if (imageData) {
+          mimeType = inferMimeTypeFromBase64(imageData)
+          
+          let finalBase64Data = extractBase64Data(imageData)
+          let finalMimeType = mimeType
+          
+          if (needsConversion(mimeType)) {
+            log(`[look_at] Detected unsupported Base64 format: ${mimeType}, converting to JPEG...`)
+            try {
+              const { base64, tempFiles } = convertBase64ImageToJpeg(finalBase64Data, mimeType)
+              finalBase64Data = base64
+              finalMimeType = "image/jpeg"
+              tempFilesToCleanup = tempFiles
+              log(`[look_at] Base64 conversion successful`)
+            } catch (conversionError) {
+              log(`[look_at] Base64 conversion failed: ${conversionError}`)
+              return `Error: Failed to convert Base64 image format. ${conversionError}`
+            }
+          }
+          
+          filePart = {
+            type: "file",
+            mime: finalMimeType,
+            url: `data:${finalMimeType};base64,${finalBase64Data}`,
+            filename: `clipboard-image.${finalMimeType.split("/")[1] || "png"}`,
+          }
+        } else if (filePath) {
         mimeType = inferMimeTypeFromFilePath(filePath)
+        
+        let actualFilePath = filePath
+        if (needsConversion(mimeType)) {
+          log(`[look_at] Detected unsupported format: ${mimeType}, converting to JPEG...`)
+          try {
+            tempFilePath = convertImageToJpeg(filePath, mimeType)
+            actualFilePath = tempFilePath
+            mimeType = "image/jpeg"
+            log(`[look_at] Conversion successful: ${tempFilePath}`)
+          } catch (conversionError) {
+            log(`[look_at] Conversion failed: ${conversionError}`)
+            return `Error: Failed to convert image format. ${conversionError}`
+          }
+        }
+
         filePart = {
           type: "file",
           mime: mimeType,
-          url: pathToFileURL(filePath).href,
-          filename: basename(filePath),
+          url: pathToFileURL(actualFilePath).href,
+          filename: basename(actualFilePath),
         }
       } else {
         return "Error: Must provide either 'file_path' or 'image_data'."
@@ -149,8 +191,14 @@ Original error: ${createResult.error}`
         return "Error: No response from multimodal-looker agent"
       }
 
-      log(`[look_at] Got response, length: ${responseText.length}`)
-      return responseText
+        log(`[look_at] Got response, length: ${responseText.length}`)
+        return responseText
+      } finally {
+        if (tempFilePath) {
+          cleanupConvertedImage(tempFilePath)
+        }
+        tempFilesToCleanup.forEach(file => cleanupConvertedImage(file))
+      }
     },
   })
 }