Initial QSfera import

Server/services/thumbnails/pkg/preprocessor/preprocessor_imaging.go

@@ -0,0 +1,22 @@
+//go:build !enable_vips
+
+package preprocessor
+
+import (
+	"io"
+
+	"github.com/kovidgoyal/imaging"
+	"github.com/pkg/errors"
+)
+
+// ImageDecoder is a converter for the image file
+type ImageDecoder struct{}
+
+// Convert reads the image file and returns the thumbnail image
+func (i ImageDecoder) Convert(r io.Reader) (any, error) {
+	img, err := imaging.Decode(r, imaging.AutoOrientation(true))
+	if err != nil {
+		return nil, errors.Wrap(err, `could not decode the image`)
+	}
+	return img, nil
+}