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

samplecode/DecodeFile.h

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #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()));
     if (!codec) {
         return false;
     }
 
     SkImageInfo info = codec->getInfo().makeColorType(colorType);
     if (requireUnpremul && kPremul_SkAlphaType == info.alphaType()) {
         info = info.makeAlphaType(kUnpremul_SkAlphaType);
     }
 
     if (!bitmap->tryAllocPixels(info)) {
         return false;
     }
 
     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;
+}