//best effort set location from exif data.
func setLocationFromExif(l *core.LatLon, x *exif.Exif) {
lat, err := x.Get(exif.GPSLatitude)
if err != nil || lat.Format() != tiff.RatVal || lat.Count != 3 {
return
}
lon, err := x.Get(exif.GPSLongitude)
if err != nil || lon.Format() != tiff.RatVal || lon.Count != 3 {
return
}
//we should have 3 rational values. and this lib panics on fail.
//so we did the checks first.
//OK it no longer panics, so we need to error check. so we add a helper
rats := func(tag *tiff.Tag) []*big.Rat {
r := make([]*big.Rat, 3)
r[0], _ = tag.Rat(0)
r[1], _ = tag.Rat(1)
r[2], _ = tag.Rat(2)
return r
}
l.Lat = toDecimalDegreesFromRat(rats(lat))
l.Lon = toDecimalDegreesFromRat(rats(lon))
//l is a pointer, so we have filled in the values now,
// and do not need to return anything.
}
func tagTime(ex *exif.Exif, ts exif.FieldName) (t time.Time, err error) {
t = time.Unix(0, 0)
tg, err := ex.Get(ts)
if err != nil {
return
}
str_val, err := tg.StringVal()
if err != nil {
return
}
t, err = time.Parse("2006:01:02 15:04:05", str_val)
return
}
// Returns pointer to struct GeoFields
// can easily be accessed E.Lat, E.Long etc
func GetGPS(E *exif.Exif) (*GeoFields, error) {
F := new(GeoFields)
LatVal, err := E.Get("GPSLatitude")
if err != nil {
return nil, err
}
F.Lat = FormatGPS(LatVal)
LongVal, err := E.Get("GPSLongitude")
if err != nil {
return nil, err
}
F.Long = FormatGPS(LongVal)
//Need to add more comments. Would help
LatRefVal, err := E.Get("GPSLatitudeRef") //Lat and LatRef
if err != nil {
return nil, err
}
F.LatRef = LatRefVal.String()
LongRefVal, err := E.Get("GPSLongitudeRef")
if err != nil {
return nil, err
}
F.LongRef = LongRefVal.String()
// *** Longitude
return F, nil
}
// Parse the date string from an exif tag and return the year, month and day
// in the format YYYYMMDD.
func (i *ImageObj) getDatePath(tags *exif.Exif) (string, error) {
value, err := tags.Get(exif.DateTimeOriginal)
if err != nil {
return "", err
}
dateStr, err := value.StringVal()
if err != nil {
return "", err
}
dateSlice := strings.SplitN(dateStr, ":", 3)
return path.Join(dateSlice[0], dateSlice[1]), nil
}
func ImageOrientation(ii *ImageInfo, x *exif.Exif) {
orientation, err := x.Get(exif.Orientation)
if err != nil {
log.Println("o err: ", err)
return
}
or := 0
if orientation.Val[0] != 0 {
or = int(orientation.Val[0])
}
if orientation.Val[1] != 0 {
or = int(orientation.Val[1])
}
ii.Orientation = or
}
// This is basically a copy of the exif.Exif.DateTime() method, except:
// * it takes a *time.Location to assume
// * the caller already assumes there's no timezone offset or GPS time
// in the EXIF, so any of that code can be ignored.
func exifDateTimeInLocation(x *exif.Exif, loc *time.Location) (time.Time, error) {
tag, err := x.Get(exif.DateTimeOriginal)
if err != nil {
tag, err = x.Get(exif.DateTime)
if err != nil {
return time.Time{}, err
}
}
if tag.Format() != tiff.StringVal {
return time.Time{}, errors.New("DateTime[Original] not in string format")
}
const exifTimeLayout = "2006:01:02 15:04:05"
dateStr := strings.TrimRight(string(tag.Val), "\x00")
return time.ParseInLocation(exifTimeLayout, dateStr, loc)
}
func tagInt(ex *exif.Exif, ts exif.FieldName) (val int32, err error) {
val = -1
tg, err := ex.Get(ts)
if err != nil {
return
}
if tg.Count != 1 {
err = errors.New(fmt.Sprintf("Tag count not 1: %s", ts))
return
}
int_val, err := tg.Int(0)
if err == nil {
val = int32(int_val)
}
return
}
// Parse decodes all Nikon makernote data found in x and adds it to x.
func (_ *nikonV3) Parse(x *exif.Exif) error {
m, err := x.Get(exif.MakerNote)
if err != nil {
return nil
} else if bytes.Compare(m.Val[:6], []byte("Nikon\000")) != 0 {
return nil
}
// Nikon v3 maker note is a self-contained IFD (offsets are relative
// to the start of the maker note)
mkNotes, err := tiff.Decode(bytes.NewReader(m.Val[10:]))
if err != nil {
return err
}
x.LoadTags(mkNotes.Dirs[0], makerNoteNikon3Fields, false)
return nil
}
func NewGeoPhotoFromExif(exifData *exif.Exif) GeoPhoto {
GPSLatitude, _ := exifData.Get(exif.GPSLatitude)
GPSLatitudeRef, _ := exifData.Get(exif.GPSLatitudeRef)
GPSLongitude, _ := exifData.Get(exif.GPSLongitude)
GPSLongitudeRef, _ := exifData.Get(exif.GPSLongitudeRef)
GPSTimeStamp, _ := exifData.Get(exif.GPSTimeStamp)
GPSDateStamp, _ := exifData.Get(exif.GPSDateStamp)
return GeoPhoto{
GPSLatitude: GPSLatitude,
GPSLatitudeRef: GPSLatitudeRef,
GPSLongitude: GPSLongitude,
GPSLongitudeRef: GPSLongitudeRef,
GPSTimeStamp: GPSTimeStamp,
GPSDateStamp: GPSDateStamp,
}
}
// Generate a thumbnail from the given image, save it to S3, and save the record to the DB.
func SaveThumbnail(
proc func(image.Image, int, int, imaging.ResampleFilter) *image.NRGBA,
photoId int32,
photoImage image.Image,
ex *exif.Exif,
width, height int32) {
thumbnail := proc(photoImage, int(width), int(height), imaging.Lanczos)
// If the EXIF says to, rotate the thumbnail.
var orientation int = 1
if ex != nil {
if orientationTag, err := ex.Get(exif.Orientation); err == nil {
orientation = int(orientationTag.Int(0))
}
if rotateFunc, ok := REORIENTATION_FUNCS[orientation]; ok && rotateFunc != nil {
thumbnail = rotateFunc(thumbnail)
}
}
var thumbnailBuffer bytes.Buffer
err := jpeg.Encode(&thumbnailBuffer, thumbnail, nil)
if err != nil {
rev.ERROR.Println("Failed to create thumbnail:", err)
return
}
thumbnailModel := &models.Thumbnail{
PhotoId: photoId,
Width: width,
Height: height,
}
err = PHOTO_BUCKET.PutReader(thumbnailModel.S3Path(),
&thumbnailBuffer,
int64(thumbnailBuffer.Len()),
"image/jpeg",
s3.PublicRead)
if err != nil {
rev.ERROR.Println("Failed to create thumbnail:", err)
return
}
dbm.Insert(thumbnailModel)
}
// Parse decodes all Canon makernote data found in x and adds it to x.
func (_ *canon) Parse(x *exif.Exif) error {
m, err := x.Get(exif.MakerNote)
if err != nil {
return nil
}
mk, err := x.Get(exif.Make)
if err != nil {
return nil
}
if val, err := mk.StringVal(); err != nil || val != "Canon" {
return nil
}
// Canon notes are a single IFD directory with no header.
// Reader offsets need to be w.r.t. the original tiff structure.
buf := bytes.NewReader(append(make([]byte, m.ValOffset), m.Val...))
buf.Seek(int64(m.ValOffset), 0)
mkNotesDir, _, err := tiff.DecodeDir(buf, x.Tiff.Order)
if err != nil {
return err
}
x.LoadTags(mkNotesDir, makerNoteCanonFields, false)
return nil
}
func (info *ExifInfo) Decode(x *exif.Exif) {
// normally, don't ignore errors!
camModel, _ := x.Get(exif.Model)
info.CameraModel, _ = camModel.StringVal()
// retrieve first (only) rat. value
focal, _ := x.Get(exif.FocalLength)
numer, _, _ := focal.Rat2(0)
//fmt.Printf("\nFocal : %v/%v", numer, denom)
info.Focal = numer
// retrieve first (only) rat. value
aperture, _ := x.Get(exif.FNumber)
numer, _, _ = aperture.Rat2(0)
//fmt.Printf("\nAperture : %v/%v", numer, denom)
info.Aperture = numer
iso, _ := x.Get(exif.ISOSpeedRatings)
//fmt.Printf("\n%v", iso)
info.ISO = iso.String()
}
func storeImage(rw http.ResponseWriter, req *http.Request) {
// Appengine
var c appengine.Context
// Google Cloud Storage authentication
var cc gcscontext.Context
// Google Cloud Storage bucket name
var bucketName string = ""
// Google Cloud Storage client
var client *storage.Client
// Google Cloud Storage bucket
var bucketHandle *storage.BucketHandle
// User uploaded image file name
var fileName string = uuid.New()
// Transform user uploaded image to a thumbnail file name
var fileNameThumbnail string = uuid.New()
// User uploaded image file type
var contentType string = ""
// User uploaded image file raw data
var b []byte
// Google Cloud Storage file writer
var wc *storage.Writer = nil
// Error
var err error = nil
// Result, 0: success, 1: failed
var r int = http.StatusCreated
// Set response in the end
defer func() {
// Return status. WriteHeader() must be called before call to Write
if r == http.StatusCreated {
// Changing the header after a call to WriteHeader (or Write) has no effect.
// rw.Header().Set("Location", req.URL.String()+"/"+cKey.Encode())
rw.Header().Set("Location", "http://"+bucketName+".storage.googleapis.com/"+fileName)
rw.Header().Set("X-Thumbnail", "http://"+bucketName+".storage.googleapis.com/"+fileNameThumbnail)
rw.WriteHeader(r)
} else {
http.Error(rw, http.StatusText(r), r)
}
}()
// To log information in Google APP Engine console
c = appengine.NewContext(req)
// Get data from body
b, err = ioutil.ReadAll(req.Body)
if err != nil {
c.Errorf("%s in reading body", err)
r = http.StatusInternalServerError
return
}
c.Infof("Body length %d bytes, read %d bytes", req.ContentLength, len(b))
// Determine filename extension from content type
contentType = req.Header["Content-Type"][0]
switch contentType {
case "image/jpeg":
fileName += ".jpg"
fileNameThumbnail += ".jpg"
default:
c.Errorf("Unknown or unsupported content type '%s'. Valid: image/jpeg", contentType)
r = http.StatusBadRequest
return
}
c.Infof("Content type %s is received, %s is detected.", contentType, http.DetectContentType(b))
// Prepare Google Cloud Storage authentication
cc = gcsappengine.NewContext(req)
if client, err = storage.NewClient(cc); err != nil {
c.Errorf("%s in initializing a GCS client", err)
r = http.StatusInternalServerError
return
}
defer client.Close()
// Get default bucket
if bucketName, err = gcsfile.DefaultBucketName(cc); err != nil {
c.Errorf("%s in getting default GCS bucket name", err)
r = http.StatusInternalServerError
return
}
bucketHandle = client.Bucket(bucketName)
c.Infof("APP Engine Version: %s", gcsappengine.VersionID(cc))
c.Infof("Using bucket name: %s", bucketName)
// Change default object ACLs
if err = bucketHandle.DefaultObjectACL().Set(cc, storage.AllUsers, storage.RoleReader); err != nil {
c.Errorf("%v in saving default object ACL rule for bucket %q", err, bucketName)
r = http.StatusInternalServerError
return
}
// Store rotated image in Google Cloud Storage
var in *bytes.Reader = bytes.NewReader(b)
var x *exif.Exif = nil
var orientation *tiff.Tag = nil
var beforeImage image.Image
var afterImage *image.NRGBA = nil
// Read EXIF
if _, err = in.Seek(0, 0); err != nil {
c.Errorf("%s in moving the reader offset to the beginning in order to read EXIF", err)
return
}
if x, err = exif.Decode(in); err != nil {
c.Errorf("%s in decoding JPEG image", err)
return
}
// Get Orientation
if orientation, err = x.Get(exif.Orientation); err != nil {
c.Warningf("%s in getting orientation from EXIF", err)
return
}
c.Debugf("Orientation %s", orientation.String())
// Open image
if _, err = in.Seek(0, 0); err != nil {
c.Errorf("%s in moving the reader offset to the beginning in order to read EXIF", err)
return
}
if beforeImage, err = imaging.Decode(in); err != nil {
c.Errorf("%s in opening image %s", err)
return
}
switch orientation.String() {
case "1":
afterImage = beforeImage.(*image.NRGBA)
case "2":
afterImage = imaging.FlipH(beforeImage)
case "3":
afterImage = imaging.Rotate180(beforeImage)
case "4":
afterImage = imaging.FlipV(beforeImage)
case "5":
afterImage = imaging.Transverse(beforeImage)
case "6":
afterImage = imaging.Rotate270(beforeImage)
case "7":
afterImage = imaging.Transpose(beforeImage)
case "8":
afterImage = imaging.Rotate90(beforeImage)
}
// Save rotated image
wc = bucketHandle.Object(fileName).NewWriter(cc)
wc.ContentType = contentType
if err = imaging.Encode(wc, afterImage, imaging.JPEG); err != nil {
c.Errorf("%s in saving rotated image", err)
return
}
if err = wc.Close(); err != nil {
c.Errorf("CreateFile: unable to close bucket %q, file %q: %v", bucketName, fileName, err)
r = 1
return
}
wc = nil
// Make thumbnail
if afterImage.Rect.Dx() > afterImage.Rect.Dy() {
afterImage = imaging.Resize(afterImage, 1920, 0, imaging.Lanczos)
} else {
afterImage = imaging.Resize(afterImage, 0, 1920, imaging.Lanczos)
}
// Save thumbnail
wc = bucketHandle.Object(fileNameThumbnail).NewWriter(cc)
wc.ContentType = contentType
if imaging.Encode(wc, afterImage, imaging.JPEG); err != nil {
c.Errorf("%s in saving image thumbnail", err)
return
}
if err = wc.Close(); err != nil {
c.Errorf("CreateFileThumbnail: unable to close bucket %q, file %q: %v", bucketName, fileNameThumbnail, err)
r = 1
return
}
c.Infof("/%v/%v, /%v/%v created", bucketName, fileName, bucketName, fileNameThumbnail)
}