From 4f62aaf90dd70e6aa76da53c43828f857e493b97 Mon Sep 17 00:00:00 2001
From: Roman Zipp <ich@ich.wtf>
Date: Sun, 23 Jan 2022 16:59:51 +0100
Subject: [PATCH] Add blur image step

---
 README.md                    | 15 ++++++++++++
 pipelines/executable_step.go | 14 +++++++++++
 pipelines/pipeline_test.go   | 46 ++++++++++++++++++++++++++++++++++++
 pipelines/step.go            |  8 +++++++
 4 files changed, 83 insertions(+)

diff --git a/README.md b/README.md
index c601a7f..7101b4e 100644
--- a/README.md
+++ b/README.md
@@ -260,6 +260,21 @@ Invert image colors.
 }
 ```
 
+#### Blur
+
+Blur image using Gaussian functions.
+
+**Step definition**:
+
+```json
+{
+  "type": 6,
+  "options": {
+    "sigma": 50.0
+  }
+}
+```
+
 ## Authors
 
 - [Fabian Vowie](https://gogs.informatik.hs-fulda.de/FabianVowie)
diff --git a/pipelines/executable_step.go b/pipelines/executable_step.go
index 3909ad4..c20c8c0 100644
--- a/pipelines/executable_step.go
+++ b/pipelines/executable_step.go
@@ -100,3 +100,17 @@ func (s InvertImageStep) Execute(src image.Image) (image.Image, error) {
 	src = imaging.Invert(src)
 	return src, nil
 }
+
+// Blur image
+
+type BlurImageStep struct {
+	Step
+	Options struct {
+		Sigma float64 `json:"sigma"`
+	} `json:"options"`
+}
+
+func (s BlurImageStep) Execute(src image.Image) (image.Image, error) {
+	src = imaging.Blur(src, s.Options.Sigma)
+	return src, nil
+}
diff --git a/pipelines/pipeline_test.go b/pipelines/pipeline_test.go
index 1c1ec00..d2d6857 100644
--- a/pipelines/pipeline_test.go
+++ b/pipelines/pipeline_test.go
@@ -409,6 +409,52 @@ func TestExecuteSteps(t *testing.T) {
 		os.Remove(storageProvider.GetPath(Bucket, dest))
 	})
 
+	t.Run("Image blur step is successful", func(t *testing.T) {
+		const Bucket string = "pipeline_test_10"
+		const Payload string = `{
+			"name": "example pipeline",
+			"type": 1,
+			"removeMetadata": false,
+			"steps": [
+				{
+					"name": "blur",
+					"type": 6,
+					"options": {
+						"sigma": 50.0
+					}
+				}
+			]
+		}`
+
+		wd, _ := os.Getwd()
+		pipe := DeserializePipelines([][]byte{[]byte(Payload)})[0]
+
+		storageProvider := storage.GetFileSystemStorageProvider("test", "..")
+
+		// copy test file to storage bucket
+		_, err := storageProvider.StoreExisting(Bucket, "source.jpg", filepath.Join(wd, "../tests/files/900x900.jpg"))
+		assert.Nil(t, err, "Test file should be readable")
+		assert.FileExists(t, storageProvider.GetPath(Bucket, "source.jpg"))
+
+		// run pipeline steps
+		dest, err := pipe.Run("source.jpg", Bucket, storageProvider)
+		assert.Nil(t, err)
+		assert.FileExists(t, storageProvider.GetPath(Bucket, dest))
+
+		// read image config
+		file, err := storageProvider.OpenFile(Bucket, dest)
+		assert.Nil(t, err)
+
+		imgConf, _, err := image.DecodeConfig(file)
+		assert.Nil(t, err)
+
+		assert.Equal(t, 900, imgConf.Width)
+		assert.Equal(t, 900, imgConf.Height)
+
+		// clean up
+		os.Remove(storageProvider.GetPath(Bucket, "source.jpg"))
+		os.Remove(storageProvider.GetPath(Bucket, dest))
+	})
 }
 
 // output options
diff --git a/pipelines/step.go b/pipelines/step.go
index 90919b3..f6d18d5 100644
--- a/pipelines/step.go
+++ b/pipelines/step.go
@@ -14,6 +14,7 @@ const (
 	TypeGrayscaleImageStep
 	TypeFitImageStep
 	TypeInvertImageStep
+	TypeBlurImageStep
 )
 
 type Step struct {
@@ -58,6 +59,13 @@ func (s Step) GetExecutable() (IExecutableStep, error) {
 
 	case TypeGrayscaleImageStep:
 		return GrayscaleImageStep{}, nil
+
+	case TypeBlurImageStep:
+		step := BlurImageStep{}
+		if err := json.Unmarshal(s.Options, &step.Options); err != nil {
+			return nil, err
+		}
+		return step, nil
 	}
 
 	return nil, errors.New("invalid type")