[chore] Only call imaging.Resize when necessary, use even tinier blurhashes (#3247)

* [chore] Use `imaging.Fit`, use even tinier blurhashes

* avoid calling resize if not necessary

* update blurhashes + thumb

internal/api/client/instance/instancepatch_test.go

@@ -858,7 +858,7 @@ func (suite *InstancePatchTestSuite) TestInstancePatch8() {
   "static_url": "http://localhost:8080/fileserver/01AY6P665V14JJR0AFVRT7311Y/attachment/small/`+instanceAccount.AvatarMediaAttachment.ID+`.webp",`+`
   "thumbnail_static_type": "image/webp",
   "thumbnail_description": "A bouncing little green peglin.",
-  "blurhash": "LE9as6M}4YtO%dRlWEt6Dmoxx?WC"
+  "blurhash": "LF9kG$RR4YtP%dR+V^t5D,oxx?WC"
 }`, string(instanceV2ThumbnailJson))
 
 	// double extra special bonus: now update the image description without changing the image

internal/api/client/media/mediacreate_test.go

@@ -206,7 +206,7 @@ func (suite *MediaCreateTestSuite) TestMediaCreateSuccessful() {
 			Y: 0.5,
 		},
 	}, *attachmentReply.Meta)
-	suite.Equal("LjCGfG#6RkRn_NvzRjWF?urqV@a$", *attachmentReply.Blurhash)
+	suite.Equal("LiBzRk#6V[WF_NvzV@WY_3rqV@a$", *attachmentReply.Blurhash)
 	suite.NotEmpty(attachmentReply.ID)
 	suite.NotEmpty(attachmentReply.URL)
 	suite.NotEmpty(attachmentReply.PreviewURL)
@@ -291,7 +291,7 @@ func (suite *MediaCreateTestSuite) TestMediaCreateSuccessfulV2() {
 			Y: 0.5,
 		},
 	}, *attachmentReply.Meta)
-	suite.Equal("LjCGfG#6RkRn_NvzRjWF?urqV@a$", *attachmentReply.Blurhash)
+	suite.Equal("LiBzRk#6V[WF_NvzV@WY_3rqV@a$", *attachmentReply.Blurhash)
 	suite.NotEmpty(attachmentReply.ID)
 	suite.Nil(attachmentReply.URL)
 	suite.NotEmpty(attachmentReply.PreviewURL)

internal/media/manager_test.go

@@ -276,7 +276,7 @@ func (suite *ManagerTestSuite) TestSimpleJpegProcess() {
 	suite.Equal("image/jpeg", attachment.Thumbnail.ContentType)
 	suite.Equal(269739, attachment.File.FileSize)
 	suite.Equal(22858, attachment.Thumbnail.FileSize)
-	suite.Equal("LjCGfG#6RkRn_NvzRjWF?urqV@a$", attachment.Blurhash)
+	suite.Equal("LiBzRk#6V[WF_NvzV@WY_3rqV@a$", attachment.Blurhash)
 
 	// now make sure the attachment is in the database
 	dbAttachment, err := suite.db.GetAttachmentByID(ctx, attachment.ID)
@@ -429,7 +429,7 @@ func (suite *ManagerTestSuite) TestSlothVineProcess() {
 	suite.Equal("image/webp", attachment.Thumbnail.ContentType)
 	suite.Equal(312453, attachment.File.FileSize)
 	suite.Equal(5648, attachment.Thumbnail.FileSize)
-	suite.Equal("LhIrNMt6Nsj[t7ayW.j[_4WBsWkB", attachment.Blurhash)
+	suite.Equal("LfIYH~xtNskCxtfPW.kB_4aespof", attachment.Blurhash)
 
 	// now make sure the attachment is in the database
 	dbAttachment, err := suite.db.GetAttachmentByID(ctx, attachment.ID)
@@ -489,7 +489,7 @@ func (suite *ManagerTestSuite) TestLongerMp4Process() {
 	suite.Equal("image/webp", attachment.Thumbnail.ContentType)
 	suite.Equal(109569, attachment.File.FileSize)
 	suite.Equal(2976, attachment.Thumbnail.FileSize)
-	suite.Equal("L8QJfm~qD%_3_3D%t7RjM{j[ofRj", attachment.Blurhash)
+	suite.Equal("LJQJfm?bM{?b~qRjt7WBayWBofWB", attachment.Blurhash)
 
 	// now make sure the attachment is in the database
 	dbAttachment, err := suite.db.GetAttachmentByID(ctx, attachment.ID)
@@ -549,7 +549,7 @@ func (suite *ManagerTestSuite) TestBirdnestMp4Process() {
 	suite.Equal("image/webp", attachment.Thumbnail.ContentType)
 	suite.Equal(1409625, attachment.File.FileSize)
 	suite.Equal(14478, attachment.Thumbnail.FileSize)
-	suite.Equal("LKF~w1RjRO.99DM_RPaetkV?WCMw", attachment.Blurhash)
+	suite.Equal("LJF?FZV@RO.99DM_RPWAx]V?ayMw", attachment.Blurhash)
 
 	// now make sure the attachment is in the database
 	dbAttachment, err := suite.db.GetAttachmentByID(ctx, attachment.ID)
@@ -657,7 +657,7 @@ func (suite *ManagerTestSuite) TestPngNoAlphaChannelProcess() {
 	suite.Equal("image/jpeg", attachment.Thumbnail.ContentType)
 	suite.Equal(17471, attachment.File.FileSize)
 	suite.Equal(6446, attachment.Thumbnail.FileSize)
-	suite.Equal("LDQcrD%i-?aj%ho#M~RP~nf3~nt2", attachment.Blurhash)
+	suite.Equal("LFQT7e.A%O%4?co$M}M{_1W9~TxV", attachment.Blurhash)
 
 	// now make sure the attachment is in the database
 	dbAttachment, err := suite.db.GetAttachmentByID(ctx, attachment.ID)
@@ -713,7 +713,7 @@ func (suite *ManagerTestSuite) TestPngAlphaChannelProcess() {
 	suite.Equal("image/webp", attachment.Thumbnail.ContentType)
 	suite.Equal(18832, attachment.File.FileSize)
 	suite.Equal(3592, attachment.Thumbnail.FileSize)
-	suite.Equal("LBOW$@%i-rak%go#RSRP_1av~Ts+", attachment.Blurhash)
+	suite.Equal("LCONII.A%Oxw?co#M}M{_1ac~TxV", attachment.Blurhash)
 
 	// now make sure the attachment is in the database
 	dbAttachment, err := suite.db.GetAttachmentByID(ctx, attachment.ID)
@@ -769,7 +769,7 @@ func (suite *ManagerTestSuite) TestSimpleJpegProcessWithCallback() {
 	suite.Equal("image/jpeg", attachment.Thumbnail.ContentType)
 	suite.Equal(269739, attachment.File.FileSize)
 	suite.Equal(22858, attachment.Thumbnail.FileSize)
-	suite.Equal("LjCGfG#6RkRn_NvzRjWF?urqV@a$", attachment.Blurhash)
+	suite.Equal("LiBzRk#6V[WF_NvzV@WY_3rqV@a$", attachment.Blurhash)
 
 	// now make sure the attachment is in the database
 	dbAttachment, err := suite.db.GetAttachmentByID(ctx, attachment.ID)
@@ -847,7 +847,7 @@ func (suite *ManagerTestSuite) TestSimpleJpegProcessWithDiskStorage() {
 	suite.Equal("image/jpeg", attachment.Thumbnail.ContentType)
 	suite.Equal(269739, attachment.File.FileSize)
 	suite.Equal(22858, attachment.Thumbnail.FileSize)
-	suite.Equal("LjCGfG#6RkRn_NvzRjWF?urqV@a$", attachment.Blurhash)
+	suite.Equal("LiBzRk#6V[WF_NvzV@WY_3rqV@a$", attachment.Blurhash)
 
 	// now make sure the attachment is in the database
 	dbAttachment, err := suite.db.GetAttachmentByID(ctx, attachment.ID)

internal/media/thumbnail.go

@@ -34,6 +34,40 @@
 	"golang.org/x/image/webp"
 )
 
+const (
+	maxThumbWidth  = 512
+	maxThumbHeight = 512
+)
+
+// thumbSize returns the dimensions to use for an input
+// image of given width / height, for its outgoing thumbnail.
+// This attempts to maintains the original image aspect ratio.
+func thumbSize(width, height int, aspect float32) (int, int) {
+
+	switch {
+	// Simplest case, within bounds!
+	case width < maxThumbWidth &&
+		height < maxThumbHeight:
+		return width, height
+
+	// Width is larger side.
+	case width > height:
+		// i.e. height = newWidth * (height / width)
+		height = int(float32(maxThumbWidth) / aspect)
+		return maxThumbWidth, height
+
+	// Height is larger side.
+	case height > width:
+		// i.e. width = newHeight * (width / height)
+		width = int(float32(maxThumbHeight) * aspect)
+		return width, maxThumbHeight
+
+	// Square.
+	default:
+		return maxThumbWidth, maxThumbHeight
+	}
+}
+
 // generateThumb generates a thumbnail for the
 // input file at path, resizing it to the given
 // dimensions and generating a blurhash if needed.
@@ -229,11 +263,17 @@ func generateNativeThumb(
 		img = imaging.Transverse(img)
 	}
 
-	// Resize image to dimens.
-	img = imaging.Resize(img,
-		width, height,
-		imaging.Linear,
-	)
+	// Resize image to dimens only if necessary.
+	if img.Bounds().Dx() > maxThumbWidth ||
+		img.Bounds().Dy() > maxThumbHeight {
+		// Note: We could call "imaging.Fit" here
+		// but there's no point, as we've already
+		// calculated target dimensions beforehand.
+		img = imaging.Resize(img,
+			width, height,
+			imaging.Linear,
+		)
+	}
 
 	// Open output file at given path.
 	outfile, err := os.Create(outpath)
@@ -255,7 +295,7 @@ func generateNativeThumb(
 	if needBlurhash {
 		// for generating blurhashes, it's more cost effective to
 		// lose detail since it's blurry, so make a tiny version.
-		tiny := imaging.Resize(img, 64, 64, imaging.NearestNeighbor)
+		tiny := imaging.Resize(img, 32, 0, imaging.NearestNeighbor)
 
 		// Drop the larger image
 		// ref as soon as possible
@@ -294,7 +334,7 @@ func generateWebpBlurhash(filepath string) (string, error) {
 
 	// for generating blurhashes, it's more cost effective to
 	// lose detail since it's blurry, so make a tiny version.
-	tiny := imaging.Resize(img, 64, 64, imaging.NearestNeighbor)
+	tiny := imaging.Resize(img, 32, 0, imaging.NearestNeighbor)
 
 	// Drop the larger image
 	// ref as soon as possible

internal/media/util.go

@@ -39,39 +39,6 @@ func getExtension(path string) string {
 	return ""
 }
 
-// thumbSize returns the dimensions to use for an input
-// image of given width / height, for its outgoing thumbnail.
-// This attempts to maintains the original image aspect ratio.
-func thumbSize(width, height int, aspect float32) (int, int) {
-	const (
-		maxThumbWidth  = 512
-		maxThumbHeight = 512
-	)
-
-	switch {
-	// Simplest case, within bounds!
-	case width < maxThumbWidth &&
-		height < maxThumbHeight:
-		return width, height
-
-	// Width is larger side.
-	case width > height:
-		// i.e. height = newWidth * (height / width)
-		height = int(float32(maxThumbWidth) / aspect)
-		return maxThumbWidth, height
-
-	// Height is larger side.
-	case height > width:
-		// i.e. width = newHeight * (width / height)
-		width = int(float32(maxThumbHeight) * aspect)
-		return width, maxThumbHeight
-
-	// Square.
-	default:
-		return maxThumbWidth, maxThumbHeight
-	}
-}
-
 // getMimeType returns a suitable mimetype for file extension.
 func getMimeType(ext string) string {
 	const defaultType = "application/octet-stream"

testrig/testmodels.go

@@ -1078,7 +1078,7 @@ func NewTestAttachments() map[string]*gtsmodel.MediaAttachment {
 			Thumbnail: gtsmodel.Thumbnail{
 				Path:        "01F8MH5ZK5VRH73AKHQM6Y9VNX/attachment/small/01FVW7RXPQ8YJHTEXYPE7Q8ZY0.jpeg",
 				ContentType: "image/jpeg",
-				FileSize:    20394,
+				FileSize:    20395,
 				URL:         "http://localhost:8080/fileserver/01F8MH5ZK5VRH73AKHQM6Y9VNX/attachment/small/01FVW7RXPQ8YJHTEXYPE7Q8ZY0.webp",
 			},
 			Avatar: util.Ptr(false),
@@ -1124,7 +1124,7 @@ func NewTestAttachments() map[string]*gtsmodel.MediaAttachment {
 			Thumbnail: gtsmodel.Thumbnail{
 				Path:        "062G5WYKY35KKD12EMSM3F8PJ8/attachment/small/01PFPMWK2FF0D9WMHEJHR07C3R.jpeg",
 				ContentType: "image/webp",
-				FileSize:    20394,
+				FileSize:    20395,
 				URL:         "http://localhost:8080/fileserver/062G5WYKY35KKD12EMSM3F8PJ8/header/small/01PFPMWK2FF0D9WMHEJHR07C3R.webp",
 			},
 			Avatar: util.Ptr(false),