func (this *CompressLosslessly) compressJpeg(image *uploadedfile.UploadedFile) error {
filename, err := processorcommand.Jpegtran(image.GetPath())
if err != nil {
return err
}
image.SetPath(filename)
return nil
}
func (this *ImageScaler) scalePng(image *uploadedfile.UploadedFile) error {
filename, err := processorcommand.ConvertToJpeg(image.GetPath())
if err != nil {
return err
}
image.SetPath(filename)
image.SetMime("image/jpeg")
return this.scaleJpeg(image)
}
func (this *ImageOrienter) Process(image *uploadedfile.UploadedFile) error {
filename, err := processorcommand.FixOrientation(image.GetPath())
if err != nil {
return err
}
image.SetPath(filename)
return nil
}
func (this *ImageScaler) scaleJpeg(image *uploadedfile.UploadedFile) error {
filename, err := processorcommand.Quality(image.GetPath(), 90)
if err != nil {
return err
}
image.SetPath(filename)
size, err := image.FileSize()
if size < this.targetSize {
return nil
}
filename, err = processorcommand.Quality(image.GetPath(), 70)
if err != nil {
return err
}
image.SetPath(filename)
size, err = image.FileSize()
if size < this.targetSize {
return nil
}
percent := 90
if (size - this.targetSize) >= (15 * 1024 * 1024) {
percent = 30
} else if (size - this.targetSize) >= (10 * 1024 * 1024) {
percent = 40
} else if (size - this.targetSize) >= (5 * 1024 * 1024) {
percent = 60
}
for {
filename, err = processorcommand.ResizePercent(image.GetPath(), percent)
if err != nil {
return err
}
image.SetPath(filename)
size, err := image.FileSize()
if err != nil {
return err
} else if size == 0 || percent < 10 {
return errors.New("Could not scale image to desired filesize")
} else if size < this.targetSize {
return nil
}
percent -= 10
}
}