feature(thumbnails): add the ability to define custom image processors (

#7409)

* feature(thumbnails): add the ability to define custom image processors

* fix(ci): add exported member comment

* docs(thumbnails): mention processors in readme

* fix: codacy and code review feedback

* fix: thumbnail readme markdown

Co-authored-by: Martin <github@diemattels.at>

---------

Co-authored-by: Martin <github@diemattels.at>

changelog/unreleased/thumbnail-processors.md

@@ -0,0 +1,22 @@
+Enhancement: Thumbnail generation with image processors
+
+Thumbnails can now be changed during creation, previously the images were always scaled to fit the given frame,
+but it could happen that the images were cut off because they could not be placed better due to the aspect ratio.
+
+This pr introduces the possibility of specifying how the behavior should be, following processors are available
+
+* resize
+* fit
+* fill
+* thumbnail
+
+the processor can be applied by adding the processor query param to the request, e.g. `processor=fit`, `processor=fill`, ...
+
+to find out more how the individual processors work please read https://github.com/disintegration/imaging
+
+if no processor is provided it behaves the same as before (resize for gif's and thumbnail for all other)
+
+https://github.com/owncloud/ocis/pull/7409
+https://github.com/owncloud/enterprise/issues/6057
+https://github.com/owncloud/ocis/issues/5179
+https://github.com/owncloud/web/issues/7728

protogen/proto/ocis/services/thumbnails/v0/thumbnails.proto

@@ -47,9 +47,11 @@ message GetThumbnailRequest {
     int32 width = 3;
     // The height of the thumbnail
     int32 height = 4;
+    // Indicates which image processor to use
+    string processor = 5;
     oneof source {
-      ocis.messages.thumbnails.v0.WebdavSource webdav_source = 5;
-      ocis.messages.thumbnails.v0.CS3Source cs3_source = 6;
+      ocis.messages.thumbnails.v0.WebdavSource webdav_source = 6;
+      ocis.messages.thumbnails.v0.CS3Source cs3_source = 7;
     }
 }
 

services/thumbnails/README.md

@@ -10,9 +10,9 @@ The relevant environment variables defining file locations are:
 -   (2) `STORAGE_USERS_OCIS_ROOT`
 -   (3) `THUMBNAILS_FILESYSTEMSTORAGE_ROOT`
 
-(1) ... Having a default set by the Infinite Scale code, but if defined, used as base path for other services.  
-(2) ... Source files, defaults to (1) plus path component, but can be freely defined if required.  
-(3) ... Target files, defaults to (1) plus path component, but can be freely defined if required.  
+(1) ... Having a default set by the Infinite Scale code, but if defined, used as base path for other services.
+(2) ... Source files, defaults to (1) plus path component, but can be freely defined if required.
+(3) ... Target files, defaults to (1) plus path component, but can be freely defined if required.
 
 For details and defaults for these environment variables see the ocis admin documentation.
 
@@ -45,9 +45,20 @@ Various resolutions can be defined via `THUMBNAILS_RESOLUTIONS`. A requestor can
 
 Example:
 
-Requested: 18x12  
-Available: 30x20, 15x10, 9x6  
-Returned: 15x10  
+Requested: 18x12
+Available: 30x20, 15x10, 9x6
+Returned: 15x10
+
+## Thumbnail Processors
+
+Image generation can be configured by defining different processors, following processors are available:
+
+*   `resize`
+*   `fit`
+*   `fill`
+*   `thumbnail`
+
+To apply one of those, a query parameter has to be added to the request, e.g. `?processor=fit`
 
 ## Deleting Thumbnails
 

services/thumbnails/pkg/service/grpc/v0/service.go

@@ -16,16 +16,17 @@ import (
 	"github.com/cs3org/reva/v2/pkg/storagespace"
 	"github.com/cs3org/reva/v2/pkg/utils"
 	"github.com/golang-jwt/jwt/v4"
+	"github.com/pkg/errors"
+	merrors "go-micro.dev/v4/errors"
+	"google.golang.org/grpc/metadata"
+
 	"github.com/owncloud/ocis/v2/ocis-pkg/log"
 	thumbnailssvc "github.com/owncloud/ocis/v2/protogen/gen/ocis/services/thumbnails/v0"
 	"github.com/owncloud/ocis/v2/services/thumbnails/pkg/preprocessor"
 	"github.com/owncloud/ocis/v2/services/thumbnails/pkg/service/grpc/v0/decorators"
 	tjwt "github.com/owncloud/ocis/v2/services/thumbnails/pkg/service/jwt"
 	"github.com/owncloud/ocis/v2/services/thumbnails/pkg/thumbnail"
 	"github.com/owncloud/ocis/v2/services/thumbnails/pkg/thumbnail/imgsource"
-	"github.com/pkg/errors"
-	merrors "go-micro.dev/v4/errors"
-	"google.golang.org/grpc/metadata"
 )
 
 // NewService returns a service implementation for Service.
@@ -124,7 +125,7 @@ func (g Thumbnail) handleCS3Source(ctx context.Context, req *thumbnailssvc.GetTh
 	if tType == "" {
 		tType = req.GetThumbnailType().String()
 	}
-	tr, err := thumbnail.PrepareRequest(int(req.Width), int(req.Height), tType, sRes.GetInfo().GetChecksum().GetSum())
+	tr, err := thumbnail.PrepareRequest(int(req.Width), int(req.Height), tType, sRes.GetInfo().GetChecksum().GetSum(), req.Processor)
 	if err != nil {
 		return "", merrors.BadRequest(g.serviceID, err.Error())
 	}
@@ -207,7 +208,7 @@ func (g Thumbnail) handleWebdavSource(ctx context.Context, req *thumbnailssvc.Ge
 	if tType == "" {
 		tType = req.GetThumbnailType().String()
 	}
-	tr, err := thumbnail.PrepareRequest(int(req.Width), int(req.Height), tType, sRes.GetInfo().GetChecksum().GetSum())
+	tr, err := thumbnail.PrepareRequest(int(req.Width), int(req.Height), tType, sRes.GetInfo().GetChecksum().GetSum(), req.Processor)
 	if err != nil {
 		return "", merrors.BadRequest(g.serviceID, err.Error())
 	}

services/thumbnails/pkg/thumbnail/encoding.go

@@ -114,8 +114,8 @@ func EncoderForType(fileType string) (Encoder, error) {
 }
 
 // GetExtForMime return the supported extension by mime
-func GetExtForMime(mime string) string {
-	ext := strings.TrimPrefix(strings.TrimSpace(strings.ToLower(mime)), "image/")
+func GetExtForMime(fileType string) string {
+	ext := strings.TrimPrefix(strings.TrimSpace(strings.ToLower(fileType)), "image/")
 	switch ext {
 	case typeJpg, typeJpeg, typePng, typeGif:
 		return ext