Remove checks for magick extension functionality

src/calibre/ebooks/mobi/writer.py

@@ -122,15 +122,14 @@ def rescale_image(data, maxsizeb, dimen=None):
     img = Image()
     quality = 95
 
-    if hasattr(img, 'set_compression_quality'):
-        img.load(data)
-        while len(data) >= maxsizeb and quality >= 10:
-            quality -= 5
-            img.set_compression_quality(quality)
-            data = img.export('jpg')
-        if len(data) <= maxsizeb:
-            return data
-        orig_data = data
+    img.load(data)
+    while len(data) >= maxsizeb and quality >= 10:
+        quality -= 5
+        img.set_compression_quality(quality)
+        data = img.export('jpg')
+    if len(data) <= maxsizeb:
+        return data
+    orig_data = data
 
     scale = 0.9
     while len(data) >= maxsizeb and scale >= 0.05:
@@ -138,8 +137,7 @@ def rescale_image(data, maxsizeb, dimen=None):
         img.load(orig_data)
         w, h = img.size
         img.size = (int(scale*w), int(scale*h))
-        if hasattr(img, 'set_compression_quality'):
-            img.set_compression_quality(quality)
+        img.set_compression_quality(quality)
         data = img.export('jpg')
         scale -= 0.05
     return data

src/calibre/utils/magick/draw.py

@@ -42,7 +42,7 @@ def save_cover_data_to(data, path, bgcolor='#ffffff', resize_to=None,
     if resize_to is not None:
         img.size = (resize_to[0], resize_to[1])
         changed = True
-    if not hasattr(img, 'has_transparent_pixels') or img.has_transparent_pixels():
+    if img.has_transparent_pixels():
         canvas = create_canvas(img.size[0], img.size[1], bgcolor)
         canvas.compose(img)
         img = canvas
@@ -72,7 +72,7 @@ def thumbnail(data, width=120, height=120, bgcolor='#ffffff', fmt='jpg'):
         img.size = (nwidth, nheight)
     canvas = create_canvas(img.size[0], img.size[1], bgcolor)
     canvas.compose(img)
-    if fmt == 'jpg' and hasattr(canvas, 'set_compression_quality'):
+    if fmt == 'jpg':
         canvas.set_compression_quality(70)
     return (canvas.size[0], canvas.size[1], canvas.export(fmt))