@@ -188,0 +201,4 @@
+		return err
+	}
+	if !exists {
+		return caches.ErrCacheMiss

@@ -156,0 +170,4 @@
+	if preview {
+		err := taskAttachment.ReadPreview()
+		if err == nil {
+			log.Infof("Cached attachment image preview found for task attachment %v", taskAttachment.ID)

@@ -166,2 +190,4 @@
 	}
 
+	// If a preview is requested and the preview was not cached, we create the preview and cache it
+	if preview {

@@ -167,1 +191,4 @@
 
+	// If a preview is requested and the preview was not cached, we create the preview and cache it
+	if preview {
+		img, _, err := image.Decode(taskAttachment.File.File)

@@ -168,0 +197,4 @@
+		}
+
+		// Scale down the image to a minimum size
+		const minimumSize = 200

@@ -168,0 +219,4 @@
+			return handler.HandleHTTPError(err, c)
+		}
+
+		// Write the bytes to a new file in memory

@@ -185,6 +196,133 @@ func (ta *TaskAttachment) ReadAll(s *xorm.Session, _ web.Auth, _ string, page in
 	return attachments, len(attachments), numberOfTotalItems, err
 }
 
+func CacheKeyForTaskAttachmentPreview(id int64) string {

@@ -186,2 +197,4 @@
 }
 
+func CacheKeyForTaskAttachmentPreview(id int64) string {
+	return "task_attachment_preview_" + strconv.Itoa(int(id))

@@ -188,0 +211,4 @@
+		return err
+	}
+	if !exists || cached[previewSize] == nil {
+		return caches.ErrCacheMiss

@@ -188,0 +234,4 @@
+	return nil
+}
+
+func GetSize(previewSize string) int {

@@ -188,0 +264,4 @@
+	return resizedImg
+}
+
+func (ta *TaskAttachment) GeneratePreview(previewSize string) error {

@@ -44,1 +44,4 @@
 		</div>
+		<div class="field">
+			<label class="label">
+				{{ $t('user.settings.general.previewSize') }}

@@ -39,3 +49,2 @@
 
-	getBlobUrl(model: IAttachment) {
-		return AbstractService.prototype.getBlobUrl.call(this, '/tasks/' + model.taskId + '/attachments/' + model.id)
+	getBlobUrl(model: IAttachment, preview: boolean = false, size: PREVIEW_SIZE = PREVIEW_SIZE.SM) {

@@ -24,1 +27,4 @@
+	"code.vikunja.io/api/pkg/log"
+	"github.com/disintegration/imaging"
 
+	"code.vikunja.io/api/pkg/events"

@@ -186,2 +193,4 @@
 }
 
+func cacheKeyForTaskAttachmentPreview(id int64, size PreviewSize) string {
+	return "task_attachment_preview_" + strconv.Itoa(int(id)) + "_size_" + string(size)

@@ -188,0 +196,4 @@
+	return "task_attachment_preview_" + strconv.Itoa(int(id)) + "_size_" + string(size)
+}
+
+func (ta *TaskAttachment) ReadPreview(previewSize PreviewSize) []byte {

@@ -188,0 +213,4 @@
+type PreviewSize string
+
+const (
+	Small      PreviewSize = "sm"

@@ -188,0 +219,4 @@
+	ExtraLarge PreviewSize = "xl"
+)
+
+func GetSize(previewSize PreviewSize) int {

@@ -188,0 +235,4 @@
+}
+
+func Resize(img image.Image, size int) *image.NRGBA {
+	x := img.Bounds().Size().X

@@ -188,0 +249,4 @@
+	return resizedImg
+}
+
+func (ta *TaskAttachment) SavePreviewToCache(previewSize PreviewSize) []byte {

@@ -116,2 +118,4 @@
 // @Param id path int true "Task ID"
 // @Param attachmentID path int true "Attachment ID"
+// @Param preview query string false "If set to true, a preview image will be returned if the attachment is an image."
+// @Param size query string false "The size of the preview image. Can be sm, md, lg or xl."

@@ -156,0 +165,4 @@
+	}
+
+	// If the preview query parameter is set and the preview was already generated and cached, return the cached preview image
+	if preview && strings.Contains(taskAttachment.File.Mime, "image") {

@@ -156,0 +170,4 @@
+		if previewFileBytes != nil {
+			log.Debugf("Cached attachment image preview found for task attachment %v", taskAttachment.ID)
+
+			return c.Blob(http.StatusOK, taskAttachment.File.Mime, previewFileBytes)

@@ -14,6 +22,8 @@ export default class AttachmentService extends AbstractService<IAttachment> {
 		})
 	}
 
+	authStore = useAuthStore()

@@ -39,3 +49,2 @@
 
-	getBlobUrl(model: IAttachment) {
-		return AbstractService.prototype.getBlobUrl.call(this, '/tasks/' + model.taskId + '/attachments/' + model.id)
+	getBlobUrl(model: IAttachment, size?: PREVIEW_SIZE) {