Mozilla2:Image Encoding: Difference between revisions

Mozilla2:Image Encoding (view source)

478 bytes added , 8 March 2005

569

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 == Interface ==
-We need to add a new interface.  Something like:
+We need to add a new interface.  When you read from the stream should we encode just that much?  Thoughts?
-  interface imgIEncoder : nsISupports
+Something like:
+  interface imgIEncoder : nsIInputStream
   {
-    nsIOutputStream encode(imgIContainer image);
+    /* input image data
+    * result width
+    * result height
+    */
+   void init(in imgIContainer input,
+             in unsigned long width, in unsigned long height);
+ };
-   /* Output width/height */
+=== Scaling ===
-   attribute unsigned long width;
+Do we want to support different types of scaling?  I'd prefer to just do nice Bicubic resampling. [http://members.bellatlantic.net/~vze2vrva/design.html] [http://astronomy.swin.edu.au/~pbourke/colour/bicubic/]
-   attribute unsigned long height;
-   /* scaling */
+=== Brendan's comments ===
-   ??
+A reader should get the bytes requested, if not greater than length of encoded image, and it's up to the encoder to buffer more if it encodes more bytes, reading from the buffer on next read.
- };
+This expresses the idea that the encoder is something you read from.
+== Use ==
 You would create one by doing:
   createInstance("@mozilla.org/image/encoder;2?type=image/png");
-Do we want to support passing in an output stream?  When you read from the stream should we encode just that much?  Thoughts?