public int YToTileY(int y) {
        return YToTileY(y, getTileGridYOffset(), getTileHeight());
    }
Converts a pixel's Y coordinate into a vertical tile index.
This is a convenience method.  No attempt is made to detect
out-of-range coordinates.

@param y the Y coordinate of a pixel.
@return the Y index of the tile containing the pixel.
plugins/svg-plugin/batik-codec-fix/src/main/java/org/apache/batik/ext/awt/image/codec/util/SimpleRenderedImage.java