diff --git a/android/app/src/main/kotlin/deckers/thibault/aves/channel/streams/ActivityResultStreamHandler.kt b/android/app/src/main/kotlin/deckers/thibault/aves/channel/streams/ActivityResultStreamHandler.kt
index 8d7c272cf..7736d8058 100644
--- a/android/app/src/main/kotlin/deckers/thibault/aves/channel/streams/ActivityResultStreamHandler.kt
+++ b/android/app/src/main/kotlin/deckers/thibault/aves/channel/streams/ActivityResultStreamHandler.kt
@@ -188,7 +188,7 @@ class ActivityResultStreamHandler(private val activity: Activity, arguments: Any
     }
 
     private fun pickCollectionFilters() {
-        val initialFilters = (args["initialFilters"] as List<*>?)?.mapNotNull { if (it is String) it else null } ?: listOf()
+        val initialFilters = (args["initialFilters"] as? List<*>)?.mapNotNull { if (it is String) it else null } ?: listOf()
         val intent = Intent(MainActivity.INTENT_ACTION_PICK_COLLECTION_FILTERS, null, activity, MainActivity::class.java)
             .putExtra(MainActivity.EXTRA_KEY_FILTERS_ARRAY, initialFilters.toTypedArray())
             .putExtra(MainActivity.EXTRA_KEY_FILTERS_STRING, initialFilters.joinToString(MainActivity.EXTRA_STRING_ARRAY_SEPARATOR))
diff --git a/android/app/src/main/kotlin/deckers/thibault/aves/metadata/metadataextractor/SafePngMetadataReader.kt b/android/app/src/main/kotlin/deckers/thibault/aves/metadata/metadataextractor/SafePngMetadataReader.kt
index b0baa7973..1f2cc1dd5 100644
--- a/android/app/src/main/kotlin/deckers/thibault/aves/metadata/metadataextractor/SafePngMetadataReader.kt
+++ b/android/app/src/main/kotlin/deckers/thibault/aves/metadata/metadataextractor/SafePngMetadataReader.kt
@@ -28,7 +28,7 @@ object SafePngMetadataReader {
     private val LOG_TAG = LogUtils.createTag<SafePngMetadataReader>()
 
     // arbitrary size to detect chunks that may yield an OOM
-    private const val chunkSizeDangerThreshold = SafeXmpReader.segmentTypeSizeDangerThreshold
+    private const val chunkSizeDangerThreshold = SafeXmpReader.SEGMENT_TYPE_SIZE_DANGER_THRESHOLD
 
     private val latin1Encoding = Charsets.ISO_8859_1
     private val desiredChunkTypes: Set<PngChunkType> = hashSetOf(
diff --git a/android/app/src/main/kotlin/deckers/thibault/aves/metadata/metadataextractor/SafeXmpReader.kt b/android/app/src/main/kotlin/deckers/thibault/aves/metadata/metadataextractor/SafeXmpReader.kt
index 4be65a348..28115aa14 100644
--- a/android/app/src/main/kotlin/deckers/thibault/aves/metadata/metadataextractor/SafeXmpReader.kt
+++ b/android/app/src/main/kotlin/deckers/thibault/aves/metadata/metadataextractor/SafeXmpReader.kt
@@ -48,7 +48,7 @@ class SafeXmpReader : XmpReader() {
 
         extendedXMPBuffer?.let { xmpBytes ->
             val totalSize = xmpBytes.size
-            if (totalSize > segmentTypeSizeDangerThreshold) {
+            if (totalSize > SEGMENT_TYPE_SIZE_DANGER_THRESHOLD) {
                 logError(metadata, totalSize)
             } else {
                 extract(xmpBytes, metadata)
@@ -111,7 +111,7 @@ class SafeXmpReader : XmpReader() {
                     val chunkOffset = reader.uInt32.toInt()
                     if (extendedXMPBuffer == null) {
                         // TLAD insert start
-                        if (fullLength > segmentTypeSizeDangerThreshold) {
+                        if (fullLength > SEGMENT_TYPE_SIZE_DANGER_THRESHOLD) {
                             logError(metadata, fullLength)
                             return null
                         }
@@ -147,7 +147,7 @@ class SafeXmpReader : XmpReader() {
         private val LOG_TAG = LogUtils.createTag<SafeXmpReader>()
 
         // arbitrary size to detect extended XMP that may yield an OOM
-        const val segmentTypeSizeDangerThreshold = 3 * (1 shl 20) // MB
+        const val SEGMENT_TYPE_SIZE_DANGER_THRESHOLD = 3 * (1 shl 20) // MB
 
         // tighter node limits for faster loading
         val PARSE_OPTIONS: ParseOptions = ParseOptions().setXMPNodesToLimit(
diff --git a/android/app/src/main/kotlin/deckers/thibault/aves/utils/BitmapUtils.kt b/android/app/src/main/kotlin/deckers/thibault/aves/utils/BitmapUtils.kt
index 8a07860de..e1893729b 100644
--- a/android/app/src/main/kotlin/deckers/thibault/aves/utils/BitmapUtils.kt
+++ b/android/app/src/main/kotlin/deckers/thibault/aves/utils/BitmapUtils.kt
@@ -14,6 +14,9 @@ object BitmapUtils {
     private val LOG_TAG = LogUtils.createTag<BitmapUtils>()
     private const val INITIAL_BUFFER_SIZE = 2 shl 17 // 256kB
 
+    // arbitrary size to detect buffer that may yield an OOM
+    private const val BUFFER_SIZE_DANGER_THRESHOLD = 10 * (1 shl 20) // MB
+
     private val freeBaos = ArrayList<ByteArrayOutputStream>()
     private val mutex = Mutex()
 
@@ -39,6 +42,15 @@ object BitmapUtils {
                 this.compress(Bitmap.CompressFormat.JPEG, quality, stream)
             }
             if (recycle) this.recycle()
+
+            val bufferSize = stream.size()
+            if (bufferSize > BUFFER_SIZE_DANGER_THRESHOLD) {
+                val availHeapSize = Runtime.getRuntime().let { it.maxMemory() - (it.totalMemory() - it.freeMemory()) }
+                if (bufferSize > availHeapSize) {
+                    throw Exception("compressed bitmap to $bufferSize bytes, which cannot be allocated to a new byte array, with only $availHeapSize free bytes")
+                }
+            }
+
             val byteArray = stream.toByteArray()
             stream.reset()
             mutex.withLock {
@@ -59,7 +71,7 @@ object BitmapUtils {
     }
 
     fun centerSquareCrop(context: Context, bitmap: Bitmap?, size: Int): Bitmap? {
-        bitmap ?: return bitmap
+        bitmap ?: return null
         return TransformationUtils.centerCrop(getBitmapPool(context), bitmap, size, size)
     }
 
diff --git a/android/app/src/main/kotlin/deckers/thibault/aves/utils/ContextUtils.kt b/android/app/src/main/kotlin/deckers/thibault/aves/utils/ContextUtils.kt
index 0dd235137..a0683f388 100644
--- a/android/app/src/main/kotlin/deckers/thibault/aves/utils/ContextUtils.kt
+++ b/android/app/src/main/kotlin/deckers/thibault/aves/utils/ContextUtils.kt
@@ -24,7 +24,7 @@ object ContextUtils {
     }
 
     fun Context.isMyServiceRunning(serviceClass: Class<out Service>): Boolean {
-        val am = this.getSystemService(Context.ACTIVITY_SERVICE) as ActivityManager?
+        val am = this.getSystemService(Context.ACTIVITY_SERVICE) as? ActivityManager
         am ?: return false
         @Suppress("deprecation")
         return am.getRunningServices(Integer.MAX_VALUE).any { it.service.className == serviceClass.name }