From de059c82aed1ce7d475b7197b310bee8fc88a82c Mon Sep 17 00:00:00 2001
From: Travis Ralston <travpc@gmail.com>
Date: Mon, 15 Jan 2018 22:21:49 -0700
Subject: [PATCH] Honour EXIF data when thumbnailing
Fixes #37
---
.../services/thumbnail_service/thumbnailer.go | 34 +++++++++-
.../turt2live/matrix-media-repo/util/exif.go | 63 +++++++++++++++++++
vendor/manifest | 6 ++
3 files changed, 100 insertions(+), 3 deletions(-)
create mode 100644 src/github.com/turt2live/matrix-media-repo/util/exif.go
diff --git a/src/github.com/turt2live/matrix-media-repo/services/thumbnail_service/thumbnailer.go b/src/github.com/turt2live/matrix-media-repo/services/thumbnail_service/thumbnailer.go
index deaf66a8..d95881e1 100644
--- a/src/github.com/turt2live/matrix-media-repo/services/thumbnail_service/thumbnailer.go
+++ b/src/github.com/turt2live/matrix-media-repo/services/thumbnail_service/thumbnailer.go
@@ -74,6 +74,15 @@ func (t *thumbnailer) GenerateThumbnail(media *types.Media, width int, height in
}
}
+ var orientation *util.ExifOrientation = nil
+ if media.ContentType == "image/jpeg" || media.ContentType == "image/jpg" {
+ orientation, err = util.GetExifOrientation(media)
+ if err != nil {
+ t.log.Warn("Non-fatal error getting EXIF orientation: " + err.Error())
+ orientation = nil // just in case
+ }
+ }
+
contentType := "image/png"
imgData := &bytes.Buffer{}
if animated && util.ArrayContains(animatedTypes, media.ContentType) {
@@ -106,7 +115,7 @@ func (t *thumbnailer) GenerateThumbnail(media *types.Media, width int, height in
draw.Draw(frameImg, img.Bounds(), img, image.ZP, draw.Over)
// Do the thumbnailing on the copied frame
- frameThumb, err := thumbnailFrame(frameImg, method, width, height, imaging.Linear)
+ frameThumb, err := thumbnailFrame(frameImg, method, width, height, imaging.Linear, nil)
if err != nil {
t.log.Error("Error generating animated thumbnail frame: " + err.Error())
return nil, err
@@ -128,7 +137,7 @@ func (t *thumbnailer) GenerateThumbnail(media *types.Media, width int, height in
return nil, err
}
} else {
- src, err = thumbnailFrame(src, method, width, height, imaging.Lanczos)
+ src, err = thumbnailFrame(src, method, width, height, imaging.Lanczos, orientation)
if err != nil {
t.log.Error("Error generating thumbnail: " + err.Error())
return nil, err
@@ -162,7 +171,7 @@ func (t *thumbnailer) GenerateThumbnail(media *types.Media, width int, height in
return thumb, nil
}
-func thumbnailFrame(src image.Image, method string, width int, height int, filter imaging.ResampleFilter) (image.Image, error) {
+func thumbnailFrame(src image.Image, method string, width int, height int, filter imaging.ResampleFilter, orientation *util.ExifOrientation) (image.Image, error) {
var result image.Image
if method == "scale" {
result = imaging.Fit(src, width, height, filter)
@@ -172,5 +181,24 @@ func thumbnailFrame(src image.Image, method string, width int, height int, filte
return nil, errors.New("unrecognized method: " + method)
}
+ if orientation != nil {
+ // Rotate first
+ if orientation.RotateDegrees == 90 {
+ result = imaging.Rotate90(result)
+ } else if orientation.RotateDegrees == 180 {
+ result = imaging.Rotate180(result)
+ } else if orientation.RotateDegrees == 270 {
+ result = imaging.Rotate270(result)
+ } // else we don't care to rotate
+
+ // Flip second
+ if orientation.FlipHorizontal {
+ result = imaging.FlipH(result)
+ }
+ if orientation.FlipVertical {
+ result = imaging.FlipV(result)
+ }
+ }
+
return result, nil
}
diff --git a/src/github.com/turt2live/matrix-media-repo/util/exif.go b/src/github.com/turt2live/matrix-media-repo/util/exif.go
new file mode 100644
index 00000000..d65ff0af
--- /dev/null
+++ b/src/github.com/turt2live/matrix-media-repo/util/exif.go
@@ -0,0 +1,63 @@
+package util
+
+import (
+ "fmt"
+ "os"
+
+ "github.com/pkg/errors"
+ "github.com/rwcarlsen/goexif/exif"
+ "github.com/turt2live/matrix-media-repo/types"
+)
+
+type ExifOrientation struct {
+ RotateDegrees int // should be 0, 90, 180, or 270
+ FlipVertical bool
+ FlipHorizontal bool
+}
+
+func GetExifOrientation(media *types.Media) (*ExifOrientation, error) {
+ if media.ContentType != "image/jpeg" && media.ContentType != "image/jpg" {
+ return nil, errors.New("image is not a jpeg")
+ }
+
+ file, err := os.Open(media.Location)
+ if err != nil {
+ return nil, err
+ }
+
+ exifData, err := exif.Decode(file)
+ if err != nil {
+ return nil, err
+ }
+
+ rawValue, err := exifData.Get(exif.Orientation)
+ if err != nil {
+ return nil, err
+ }
+
+ orientation, err := rawValue.Int(0)
+ if err != nil {
+ return nil, err
+ }
+
+ if orientation < 1 || orientation > 8 {
+ return nil, errors.New(fmt.Sprintf("orientation out of range: %d", orientation))
+ }
+
+ flipHorizontal := orientation < 5 && (orientation%2) == 0
+ flipVertical := orientation > 4 && (orientation%2) != 0
+ degrees := 0
+
+ // TODO: There's probably a better way to represent this
+ if orientation == 1 || orientation == 2 {
+ degrees = 0
+ } else if orientation == 3 || orientation == 4 {
+ degrees = 180
+ } else if orientation == 5 || orientation == 6 {
+ degrees = 270
+ } else if orientation == 7 || degrees == 8 {
+ degrees = 90
+ }
+
+ return &ExifOrientation{degrees, flipVertical, flipHorizontal}, nil
+}
diff --git a/vendor/manifest b/vendor/manifest
index 319351c9..eb215136 100644
--- a/vendor/manifest
+++ b/vendor/manifest
@@ -134,6 +134,12 @@
"revision": "3bcf86f879c771238f8a67832a1af71308801a47",
"branch": "master"
},
+ {
+ "importpath": "github.com/rwcarlsen/goexif",
+ "repository": "https://github.com/rwcarlsen/goexif",
+ "revision": "17202558c8d9c3fd047859f1a5e73fd9ae709187",
+ "branch": "go1"
+ },
{
"importpath": "github.com/sirupsen/logrus",
"repository": "https://github.com/sirupsen/logrus",
--
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