fix up ifthenelse and set_value

TODO

@@ -1,17 +1,8 @@
 
 - python:
 
-	- constants for images:
+	- update examples with new image constant rules
 
-		- support a.set_value('x', 2), where 'x' is an image arg, or
-		  an imagearray arg
-
-		- c.ifthenelse(t, e) ... if t or e are constants, we need to
-		  match to the other branch of the conditional, not to the
-		  constant
-
-		  maybe match to the constant if both t and e are numbers
-	
 	- do more tests
 
 - put exif autorotate into jpeg load

python/Vips.py

@@ -590,14 +590,19 @@ class Image(Vips.Image):
         logging.debug('assigning %s to %s' % (value, self))
         logging.debug('%s needs a %s' % (self, gtype))
 
-        # array-ize some types, if necessary
-        value = arrayize(gtype, value)
-
         # blob-ize
         if GObject.type_is_a(gtype, vips_type_blob):
             if not isinstance(value, Vips.Blob):
                 value = Vips.Blob.new(None, value)
 
+        # image-ize
+        if GObject.type_is_a(gtype, vips_type_image):
+            if not isinstance(value, Vips.Image):
+                value = imageize(match_image, value)
+
+        # array-ize some types, if necessary
+        value = arrayize(gtype, value)
+
         self.set(field, value)
 
     def floor(self):
@@ -675,6 +680,20 @@ class Image(Vips.Image):
     def exp10(self):
         return self.math(Vips.OperationMath.EXP10)
 
+    # we need different imageize rules for this operator ... we need to 
+    # imageize th and el to match each other first
+    def ifthenelse(self, th, el, **kwargs):
+        for match_image in [th, el, self]:
+            if isinstance(match_image, Vips.Image):
+                break
+
+        if not isinstance(th, Vips.Image):
+            th = imageize(match_image, th)
+        if not isinstance(el, Vips.Image):
+            el = imageize(match_image, el)
+
+        return _call_base("ifthenelse", [th, el], kwargs, self)
+
 # add operators which needs to be class methods
 
 # use find_class_methods.py to generate this list

python/example/try14.py

@@ -11,3 +11,9 @@ a = Vips.Image.black(100, 100)
 b = a.bandjoin(2)
 
 b.write_to_file("x.v")
+
+txt = Vips.Image.text("left corner", dpi = 300)
+
+c = txt.ifthenelse(2, [0, 255, 0], blend = True)
+
+c.write_to_file("x2.v")