Improve image scaling quality.

// FREEBIE

Signal/src/Models/TSMessageAdapaters/TSPhotoAdapter.m

@@ -51,6 +51,10 @@
         imageView.frame         = CGRectMake(0.0f, 0.0f, size.width, size.height);
         imageView.contentMode   = UIViewContentModeScaleAspectFill;
         imageView.clipsToBounds = YES;
+        // Use trilinear filters for better scaling quality at
+        // some performance cost.
+        imageView.layer.minificationFilter = kCAFilterTrilinear;
+        imageView.layer.magnificationFilter = kCAFilterTrilinear;
         [JSQMessagesMediaViewBubbleImageMasker applyBubbleImageMaskToMediaView:imageView
                                                                     isOutgoing:self.appliesMediaViewMaskAsOutgoing];
         self.cachedImageView = imageView;

Signal/src/view controllers/FullImageViewController.m

@@ -147,6 +147,10 @@
         self.imageView.userInteractionEnabled       = YES;
         self.imageView.clipsToBounds                = YES;
         self.imageView.layer.allowsEdgeAntialiasing = YES;
+        // Use trilinear filters for better scaling quality at
+        // some performance cost.
+        self.imageView.layer.minificationFilter = kCAFilterTrilinear;
+        self.imageView.layer.magnificationFilter = kCAFilterTrilinear;
     }
 
     [self.scrollView addSubview:self.imageView];