Add IMGPROXY_DISABLE_SHRINK_ON_LOAD config

config.go

@@ -152,6 +152,8 @@ type config struct {
 	EnforceWebp         bool
 	EnableClientHints   bool
 
+	DisableShrinkOnLoad bool
+
 	Keys          []securityKey
 	Salts         []securityKey
 	AllowInsecure bool
@@ -267,6 +269,8 @@ func init() {
 	boolEnvConfig(&conf.EnforceWebp, "IMGPROXY_ENFORCE_WEBP")
 	boolEnvConfig(&conf.EnableClientHints, "IMGPROXY_ENABLE_CLIENT_HINTS")
 
+	boolEnvConfig(&conf.DisableShrinkOnLoad, "IMGPROXY_DISABLE_SHRINK_ON_LOAD")
+
 	hexEnvConfig(&conf.Keys, "IMGPROXY_KEY")
 	hexEnvConfig(&conf.Salts, "IMGPROXY_SALT")
 	intEnvConfig(&conf.SignatureSize, "IMGPROXY_SIGNATURE_SIZE")

docs/configuration.md

@@ -200,3 +200,4 @@ imgproxy can send logs to syslog, but this feature is disabled by default. To en
 ### Miscellaneous
 
 * `IMGPROXY_BASE_URL`: base URL prefix that will be added to every requested image URL. For example, if the base URL is `http://example.com/images` and `/path/to/image.png` is requested, imgproxy will download the source image from `http://example.com/images/path/to/image.png`. Default: blank.
+* `IMGPROXY_DISABLE_SHRINK_ON_LOAD`: when `true`, disables shrink-on-load for JPEG and WebP. Allows to process the whole image in linear colorspace but dramatically slows down resizing and increases memory usage when working with large images.

process.go

@@ -284,8 +284,8 @@ func transformImage(ctx context.Context, img **C.VipsImage, data []byte, po *pro
 
 	scale := calcScale(imgWidth, imgHeight, po, imgtype)
 
-	if scale != 1 {
-		if imgtype == imageTypeSVG && data != nil {
+	if scale != 1 && data != nil {
+		if imgtype == imageTypeSVG {
 			// Load SVG with desired scale
 			if tmp, err := vipsLoadImage(data, imgtype, 1, scale, false); err == nil {
 				C.swap_and_clear(img, tmp)
@@ -294,18 +294,16 @@ func transformImage(ctx context.Context, img **C.VipsImage, data []byte, po *pro
 			}
 
 			scale = 1
-		} else {
+		} else if !conf.DisableShrinkOnLoad && scale < 1.0 {
 			// Do some shrink-on-load
-			if scale < 1.0 && data != nil {
-				if shrink := calcShink(scale, imgtype); shrink != 1 {
-					if tmp, err := vipsLoadImage(data, imgtype, shrink, 1.0, false); err == nil {
-						C.swap_and_clear(img, tmp)
-					} else {
-						return err
-					}
-
-					scale = scale * float64(shrink)
+			if shrink := calcShink(scale, imgtype); shrink != 1 {
+				if tmp, err := vipsLoadImage(data, imgtype, shrink, 1.0, false); err == nil {
+					C.swap_and_clear(img, tmp)
+				} else {
+					return err
 				}
+
+				scale = scale * float64(shrink)
 			}
 		}
 	}