myImageColumn.setCellRenderer(new DefaultCellRenderer() {

            @Override
            public void paint(GC gc, Object value) {
                GridItem item = (GridItem) value;
                Image img = getMyImage(item.getData());

                if (img != null) {
                    Rectangle bounds = getBounds();
                    Rectangle imgBounds = img.getBounds();
                    bounds.width /= 2;
                    bounds.width -= imgBounds.width / 2;
                    bounds.height /= 2;
                    bounds.height -= imgBounds.height / 2;

                    int x = bounds.width > 0 ? bounds.x + bounds.width : bounds.x;
                    int y = bounds.height > 0 ? bounds.y + bounds.height : bounds.y;

                    gc.drawImage(img, x, y);
                }
            }
        });