[image_picker] Subsample large images when resizing on Android

packages/image_picker/image_picker_android/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 0.8.13+25
+
+* Fixes resizing with `maxWidth` or `maxHeight` always decoding the full-size
+  image; large images are now subsampled while decoding.
+
 ## 0.8.13+24
 
 * Updates Robolectric to 4.17 and adds the JVM arguments it requires for unit tests.

packages/image_picker/image_picker_android/android/src/main/java/io/flutter/plugins/imagepicker/ImageResizer.java

@@ -54,7 +54,11 @@ String resizeImageIfNeeded(
               maxHeight);
       BitmapFactory.Options options = new BitmapFactory.Options();
       options.inSampleSize =
-          calculateSampleSize(options, (int) targetSize.getWidth(), (int) targetSize.getHeight());
+          calculateSampleSize(
+              (int) originalSize.getWidth(),
+              (int) originalSize.getHeight(),
+              (int) targetSize.getWidth(),
+              (int) targetSize.getHeight());
       Bitmap bmp = decodeFile(imagePath, options);
       if (bmp == null) {
         return imagePath;
@@ -160,10 +164,7 @@ private Bitmap createScaledBitmap(Bitmap bmp, int width, int height, boolean fil
    *     href="https://developer.android.com/topic/performance/graphics/load-bitmap#load-bitmap">
    *     Loading Large Bitmaps Efficiently</a>
    */
-  private int calculateSampleSize(
-      BitmapFactory.Options options, int targetWidth, int targetHeight) {
-    final int height = options.outHeight;
-    final int width = options.outWidth;
+  private int calculateSampleSize(int width, int height, int targetWidth, int targetHeight) {
     int sampleSize = 1;
     if (height > targetHeight || width > targetWidth) {
       final int halfHeight = height / 2;

packages/image_picker/image_picker_android/android/src/test/java/io/flutter/plugins/imagepicker/ImageResizerTest.java

@@ -149,6 +149,24 @@ public void onResizeImageIfNeeded_whenResizeIsNecessary_shouldDecodeBitmapPixels
     }
   }
 
+  @Test
+  public void onResizeImageIfNeeded_whenDownscaling_shouldSubsampleFromOriginalSize() {
+    try (MockedStatic<BitmapFactory> mockBitmapFactory =
+        mockStatic(BitmapFactory.class, Mockito.CALLS_REAL_METHODS)) {
+      // The 12x7 image targets 3x2, so a sample size of 2 still decodes at least the target size.
+      resizer.resizeImageIfNeeded(wideJPG.getPath(), 3.0, null, 100);
+      ArgumentCaptor<BitmapFactory.Options> argument =
+          ArgumentCaptor.forClass(BitmapFactory.Options.class);
+      mockBitmapFactory.verify(
+          () -> BitmapFactory.decodeFile(anyString(), argument.capture()), times(2));
+      assertThat(argument.getAllValues().get(1).inSampleSize, equalTo(2));
+    }
+    SizeFCompat scaledSize =
+        resizer.readFileDimensions(externalDirectory.getPath() + "/scaled_jpgImageWide.jpg");
+    assertThat(scaledSize.getWidth(), equalTo(3.0F));
+    assertThat(scaledSize.getHeight(), equalTo(2.0F));
+  }
+
   @Test
   public void
       onResizeImageIfNeeded_whenImageIsVertical_WidthIsGreaterThanOriginal_shouldResizeCorrectly() {

packages/image_picker/image_picker_android/pubspec.yaml

@@ -2,7 +2,7 @@ name: image_picker_android
 description: Android implementation of the image_picker plugin.
 repository: https://github.com/flutter/packages/tree/main/packages/image_picker/image_picker_android
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+image_picker%22
-version: 0.8.13+24
+version: 0.8.13+25
 
 environment:
   sdk: ^3.12.0