Add zoom option

processing/crop.go

@@ -53,8 +53,7 @@ func crop(pctx *pipelineContext, img *vips.Image, po *options.ProcessingOptions,
 
 func cropToResult(pctx *pipelineContext, img *vips.Image, po *options.ProcessingOptions, imgdata *imagedata.ImageData) error {
 	// Crop image to the result size
-	resultWidth := imath.Scale(po.Width, po.Dpr)
-	resultHeight := imath.Scale(po.Height, po.Dpr)
+	resultWidth, resultHeight := resultSize(po)
 
 	if po.ResizingType == options.ResizeFillDown {
 		if resultWidth > img.Width() {

processing/extend.go

@@ -2,14 +2,12 @@ package processing
 
 import (
 	"github.com/imgproxy/imgproxy/v3/imagedata"
-	"github.com/imgproxy/imgproxy/v3/imath"
 	"github.com/imgproxy/imgproxy/v3/options"
 	"github.com/imgproxy/imgproxy/v3/vips"
 )
 
 func extend(pctx *pipelineContext, img *vips.Image, po *options.ProcessingOptions, imgdata *imagedata.ImageData) error {
-	resultWidth := imath.Scale(po.Width, po.Dpr)
-	resultHeight := imath.Scale(po.Height, po.Dpr)
+	resultWidth, resultHeight := resultSize(po)
 
 	if !po.Extend.Enabled || (resultWidth <= img.Width() && resultHeight <= img.Height()) {
 		return nil

processing/prepare.go

@@ -98,6 +98,9 @@ func calcScale(width, height int, po *options.ProcessingOptions, imgtype imagety
 		}
 	}
 
+	wshrink /= po.ZoomWidth
+	hshrink /= po.ZoomHeight
+
 	if !po.Enlarge && imgtype != imagetype.SVG {
 		if wshrink < 1 {
 			hshrink /= wshrink

processing/result_size.go

@@ -0,0 +1,13 @@
+package processing
+
+import (
+	"github.com/imgproxy/imgproxy/v3/imath"
+	"github.com/imgproxy/imgproxy/v3/options"
+)
+
+func resultSize(po *options.ProcessingOptions) (int, int) {
+	resultWidth := imath.Scale(po.Width, po.Dpr*po.ZoomWidth)
+	resultHeight := imath.Scale(po.Height, po.Dpr*po.ZoomHeight)
+
+	return resultWidth, resultHeight
+}