'F' will toggle filtering for the --picture sample

samplecode/DecodeFile.h

Index: samplecode/DecodeFile.h
diff --git a/samplecode/DecodeFile.h b/samplecode/DecodeFile.h
index 3995238bd04208324fb1539e1190a136ded05465..801d67ce979b1fbd0ca9d435a5d16a299284b047 100644
--- a/samplecode/DecodeFile.h
+++ b/samplecode/DecodeFile.h
@@ -8,9 +8,11 @@
 #include "SkBitmap.h"
 #include "SkCodec.h"
 #include "SkData.h"
+#include "SkImage.h"
 
-inline bool decode_file(const char* filename, SkBitmap* bitmap,
-        SkColorType colorType = kN32_SkColorType, bool requireUnpremul = false) {
+static inline bool decode_file(const char* filename, SkBitmap* bitmap,
+                               SkColorType colorType = kN32_SkColorType,
+                               bool requireUnpremul = false) {
     SkASSERT(kIndex_8_SkColorType != colorType);
     sk_sp<SkData> data(SkData::MakeFromFileName(filename));
     SkAutoTDelete<SkCodec> codec(SkCodec::NewFromData(data.get()));
@@ -29,3 +31,8 @@ inline bool decode_file(const char* filename, SkBitmap* bitmap,
 
     return SkCodec::kSuccess == codec->getPixels(info, bitmap->getPixels(), bitmap->rowBytes());
 }
+
+static inline sk_sp<SkImage> decode_file(const char filename[]) {
+    sk_sp<SkData> data(SkData::MakeFromFileName(filename));
+    return data ? SkImage::MakeFromEncoded(data) : nullptr;
+}