add toString for F64ImageArray

Author: Martmists-GH

src/commonMain/kotlin/com/martmists/ndarray/simd/impl/F64ImageArrayImpl.kt

@@ -95,4 +95,6 @@ internal class F64ImageArrayImpl internal constructor(private val backing: F64Ar
             sum
         }.image
     }
+
+    override fun toString() = toString(8)
 }

src/desktopMain/kotlin/com/martmists/ndarray/simd/compat/image.kt

@@ -57,3 +57,7 @@ fun F64Array.Companion.fromImage(img: BufferedImage): F64ImageArray {
 
     return arr
 }
+
+fun F64ImageArray.toBufferedImage(): BufferedImage {
+    if ()
+}