added switch for preferred AOI. #122

README.md

@@ -102,6 +102,8 @@ By default images are cropped from the center of the original. You can specify a
 
 The AOI can also be embedded in the original image's metadata via EXIF or IPTC. The name of this metadata field can be configured and defaults to `aoi`. The request parameter overrides the AOI value from the image's metadata.
 
+By default, the AOI in the URL parameters has precedence over the one from the image's metadata. To prefer the embedded AOI from the metadata, set the `prefer_embedded_aoi` parameter to any non-emty value.
+
 ### Cropping mode
 
 The `crop` parameter sets the cropping mode. Available modes are:

config/default.yml

@@ -36,6 +36,7 @@ converter:
 
 cropping:
   default_mode: "aoi_coverage"
+  prefer_embedded_aoi: false
 
 constraints:
   quality:

lib/processing.js

@@ -14,6 +14,7 @@ function set_default_options(item) {
 
     options.format = options.format || analysis.format;
     options.crop = options.crop || item.conf.cropping.default_mode;
+    options.prefer_embedded_aoi = options.prefer_embedded_aoi || item.conf.prefer_embedded_aoi;
     options.strip_metadata = (typeof options.strip_metadata !== "undefined"); //ensure this is a boolean
 }
 
@@ -31,6 +32,10 @@ function extract_preset_data(item) {
 }
 
 function create_aoi(w, h, aoi) {
+    if (!aoi) {
+        return;
+    }
+
     var parts = aoi.split(",");
     if (parts.length !== 4) {
         throw new AoiFormatError(aoi);
@@ -74,7 +79,7 @@ function add_cropping(item) {
     var crop;
     var aoi;
 
-    if (typeof options.aoi !== "undefined") {
+    if (typeof options.aoi !== "undefined" && !options.prefer_embedded_aoi) {
         aoi = create_aoi(analysis.width, analysis.height, options.aoi);
     } else {
         aoi = create_aoi(analysis.width, analysis.height, analysis.aoi);