Function imagefmt::png::write

pub fn write<W: Write>(
    writer: &mut W, 
    w: usize, 
    h: usize, 
    src_fmt: ColFmt, 
    data: &[u8], 
    tgt_type: ColType, 
    src_stride: Option<usize>
) -> Result<()>

Writes an image and converts it to requested color type.