public void jpeg_core_output_dimensions()
{
/* Compute actual output image dimensions and DCT scaling choices. */
if (m_cinfo.m_scale_num * m_cinfo.block_size <= m_cinfo.m_scale_denom)
{
/* Provide 1/block_size scaling */
m_cinfo.m_output_width = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_width, (long)m_cinfo.block_size);
m_cinfo.m_output_height = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_height, (long)m_cinfo.block_size);
m_cinfo.min_DCT_h_scaled_size = 1;
m_cinfo.min_DCT_v_scaled_size = 1;
}
else if (m_cinfo.m_scale_num * m_cinfo.block_size <= m_cinfo.m_scale_denom * 2)
{
/* Provide 2/block_size scaling */
m_cinfo.m_output_width = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_width * 2L, (long)m_cinfo.block_size);
m_cinfo.m_output_height = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_height * 2L, (long)m_cinfo.block_size);
m_cinfo.min_DCT_h_scaled_size = 2;
m_cinfo.min_DCT_v_scaled_size = 2;
}
else if (m_cinfo.m_scale_num * m_cinfo.block_size <= m_cinfo.m_scale_denom * 3)
{
/* Provide 3/block_size scaling */
m_cinfo.m_output_width = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_width * 3L, (long)m_cinfo.block_size);
m_cinfo.m_output_height = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_height * 3L, (long)m_cinfo.block_size);
m_cinfo.min_DCT_h_scaled_size = 3;
m_cinfo.min_DCT_v_scaled_size = 3;
}
else if (m_cinfo.m_scale_num * m_cinfo.block_size <= m_cinfo.m_scale_denom * 4)
{
/* Provide 4/block_size scaling */
m_cinfo.m_output_width = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_width * 4L, (long)m_cinfo.block_size);
m_cinfo.m_output_height = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_height * 4L, (long)m_cinfo.block_size);
m_cinfo.min_DCT_h_scaled_size = 4;
m_cinfo.min_DCT_v_scaled_size = 4;
}
else if (m_cinfo.m_scale_num * m_cinfo.block_size <= m_cinfo.m_scale_denom * 5)
{
/* Provide 5/block_size scaling */
m_cinfo.m_output_width = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_width * 5L, (long)m_cinfo.block_size);
m_cinfo.m_output_height = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_height * 5L, (long)m_cinfo.block_size);
m_cinfo.min_DCT_h_scaled_size = 5;
m_cinfo.min_DCT_v_scaled_size = 5;
}
else if (m_cinfo.m_scale_num * m_cinfo.block_size <= m_cinfo.m_scale_denom * 6)
{
/* Provide 6/block_size scaling */
m_cinfo.m_output_width = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_width * 6L, (long)m_cinfo.block_size);
m_cinfo.m_output_height = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_height * 6L, (long)m_cinfo.block_size);
m_cinfo.min_DCT_h_scaled_size = 6;
m_cinfo.min_DCT_v_scaled_size = 6;
}
else if (m_cinfo.m_scale_num * m_cinfo.block_size <= m_cinfo.m_scale_denom * 7)
{
/* Provide 7/block_size scaling */
m_cinfo.m_output_width = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_width * 7L, (long)m_cinfo.block_size);
m_cinfo.m_output_height = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_height * 7L, (long)m_cinfo.block_size);
m_cinfo.min_DCT_h_scaled_size = 7;
m_cinfo.min_DCT_v_scaled_size = 7;
}
else if (m_cinfo.m_scale_num * m_cinfo.block_size <= m_cinfo.m_scale_denom * 8)
{
/* Provide 8/block_size scaling */
m_cinfo.m_output_width = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_width * 8L, (long)m_cinfo.block_size);
m_cinfo.m_output_height = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_height * 8L, (long)m_cinfo.block_size);
m_cinfo.min_DCT_h_scaled_size = 8;
m_cinfo.min_DCT_v_scaled_size = 8;
}
else if (m_cinfo.m_scale_num * m_cinfo.block_size <= m_cinfo.m_scale_denom * 9)
{
/* Provide 9/block_size scaling */
m_cinfo.m_output_width = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_width * 9L, (long)m_cinfo.block_size);
m_cinfo.m_output_height = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_height * 9L, (long)m_cinfo.block_size);
m_cinfo.min_DCT_h_scaled_size = 9;
m_cinfo.min_DCT_v_scaled_size = 9;
}
else if (m_cinfo.m_scale_num * m_cinfo.block_size <= m_cinfo.m_scale_denom * 10)
{
/* Provide 10/block_size scaling */
m_cinfo.m_output_width = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_width * 10L, (long)m_cinfo.block_size);
m_cinfo.m_output_height = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_height * 10L, (long)m_cinfo.block_size);
m_cinfo.min_DCT_h_scaled_size = 10;
m_cinfo.min_DCT_v_scaled_size = 10;
}
else if (m_cinfo.m_scale_num * m_cinfo.block_size <= m_cinfo.m_scale_denom * 11)
{
/* Provide 11/block_size scaling */
m_cinfo.m_output_width = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_width * 11L, (long)m_cinfo.block_size);
m_cinfo.m_output_height = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_height * 11L, (long)m_cinfo.block_size);
m_cinfo.min_DCT_h_scaled_size = 11;
m_cinfo.min_DCT_v_scaled_size = 11;
}
else if (m_cinfo.m_scale_num * m_cinfo.block_size <= m_cinfo.m_scale_denom * 12)
{
/* Provide 12/block_size scaling */
m_cinfo.m_output_width = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_width * 12L, (long)m_cinfo.block_size);
m_cinfo.m_output_height = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_height * 12L, (long)m_cinfo.block_size);
m_cinfo.min_DCT_h_scaled_size = 12;
m_cinfo.min_DCT_v_scaled_size = 12;
}
else if (m_cinfo.m_scale_num * m_cinfo.block_size <= m_cinfo.m_scale_denom * 13)
{
/* Provide 13/block_size scaling */
m_cinfo.m_output_width = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_width * 13L, (long)m_cinfo.block_size);
m_cinfo.m_output_height = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_height * 13L, (long)m_cinfo.block_size);
m_cinfo.min_DCT_h_scaled_size = 13;
m_cinfo.min_DCT_v_scaled_size = 13;
}
else if (m_cinfo.m_scale_num * m_cinfo.block_size <= m_cinfo.m_scale_denom * 14)
{
/* Provide 14/block_size scaling */
m_cinfo.m_output_width = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_width * 14L, (long)m_cinfo.block_size);
m_cinfo.m_output_height = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_height * 14L, (long)m_cinfo.block_size);
m_cinfo.min_DCT_h_scaled_size = 14;
m_cinfo.min_DCT_v_scaled_size = 14;
}
else if (m_cinfo.m_scale_num * m_cinfo.block_size <= m_cinfo.m_scale_denom * 15)
{
/* Provide 15/block_size scaling */
m_cinfo.m_output_width = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_width * 15L, (long)m_cinfo.block_size);
m_cinfo.m_output_height = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_height * 15L, (long)m_cinfo.block_size);
m_cinfo.min_DCT_h_scaled_size = 15;
m_cinfo.min_DCT_v_scaled_size = 15;
}
else {
/* Provide 16/block_size scaling */
m_cinfo.m_output_width = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_width * 16L, (long)m_cinfo.block_size);
m_cinfo.m_output_height = (int)
JpegUtils.jdiv_round_up((long)m_cinfo.m_image_height * 16L, (long)m_cinfo.block_size);
m_cinfo.min_DCT_h_scaled_size = 16;
m_cinfo.min_DCT_v_scaled_size = 16;
}
/* Recompute dimensions of components */
for (int ci = 0; ci < m_cinfo.m_num_components; ci++)
{
jpeg_component_info compptr = m_cinfo.Comp_info[ci];
compptr.DCT_h_scaled_size = m_cinfo.min_DCT_h_scaled_size;
compptr.DCT_v_scaled_size = m_cinfo.min_DCT_v_scaled_size;
}
}
