/// <summary>
/// Set default decompression parameters.
/// </summary>
private void default_decompress_parms()
{
/* Guess the input colorspace, and set output colorspace accordingly. */
/* (Wish JPEG committee had provided a real way to specify this...) */
/* Note application may override our guesses. */
switch (m_num_components)
{
case 1:
m_jpeg_color_space = J_COLOR_SPACE.JCS_GRAYSCALE;
m_out_color_space = J_COLOR_SPACE.JCS_GRAYSCALE;
break;
case 3:
if (m_saw_JFIF_marker)
{
/* JFIF implies YCbCr */
m_jpeg_color_space = J_COLOR_SPACE.JCS_YCbCr;
}
else if (m_saw_Adobe_marker)
{
switch (m_Adobe_transform)
{
case 0:
m_jpeg_color_space = J_COLOR_SPACE.JCS_RGB;
break;
case 1:
m_jpeg_color_space = J_COLOR_SPACE.JCS_YCbCr;
break;
default:
WARNMS(J_MESSAGE_CODE.JWRN_ADOBE_XFORM, m_Adobe_transform);
m_jpeg_color_space = J_COLOR_SPACE.JCS_YCbCr; /* assume it's YCbCr */
break;
}
}
else
{
/* Saw no special markers, try to guess from the component IDs */
int cid0 = m_comp_info[0].Component_id;
int cid1 = m_comp_info[1].Component_id;
int cid2 = m_comp_info[2].Component_id;
if (cid0 == 1 && cid1 == 2 && cid2 == 3)
{
/* assume JFIF w/out marker */
m_jpeg_color_space = J_COLOR_SPACE.JCS_YCbCr;
}
else if (cid0 == 82 && cid1 == 71 && cid2 == 66)
{
/* ASCII 'R', 'G', 'B' */
m_jpeg_color_space = J_COLOR_SPACE.JCS_RGB;
}
else
{
TRACEMS(1, J_MESSAGE_CODE.JTRC_UNKNOWN_IDS, cid0, cid1, cid2);
/* assume it's YCbCr */
m_jpeg_color_space = J_COLOR_SPACE.JCS_YCbCr;
}
}
/* Always guess RGB is proper output colorspace. */
m_out_color_space = J_COLOR_SPACE.JCS_RGB;
break;
case 4:
if (m_saw_Adobe_marker)
{
switch (m_Adobe_transform)
{
case 0:
m_jpeg_color_space = J_COLOR_SPACE.JCS_CMYK;
break;
case 2:
m_jpeg_color_space = J_COLOR_SPACE.JCS_YCCK;
break;
default:
WARNMS(J_MESSAGE_CODE.JWRN_ADOBE_XFORM, m_Adobe_transform);
/* assume it's YCCK */
m_jpeg_color_space = J_COLOR_SPACE.JCS_YCCK;
break;
}
}
else
{
/* No special markers, assume straight CMYK. */
m_jpeg_color_space = J_COLOR_SPACE.JCS_CMYK;
}
m_out_color_space = J_COLOR_SPACE.JCS_CMYK;
break;
default:
m_jpeg_color_space = J_COLOR_SPACE.JCS_UNKNOWN;
m_out_color_space = J_COLOR_SPACE.JCS_UNKNOWN;
break;
}
/* Set defaults for other decompression parameters. */
m_scale_num = 1; /* 1:1 scaling */
m_scale_denom = 1;
m_buffered_image = false;
m_raw_data_out = false;
m_dct_method = JpegConstants.JDCT_DEFAULT;
m_do_fancy_upsampling = true;
m_do_block_smoothing = true;
m_quantize_colors = false;
/* We set these in case application only sets quantize_colors. */
m_dither_mode = J_DITHER_MODE.JDITHER_FS;
m_two_pass_quantize = true;
m_desired_number_of_colors = 256;
m_colormap = null;
/* Initialize for no mode change in buffered-image mode. */
m_enable_1pass_quant = false;
m_enable_external_quant = false;
m_enable_2pass_quant = false;
}
// Compression parameter setup aids
/// <summary>
/// Set the JPEG colorspace (property <see cref="jpeg_compress_struct.Jpeg_color_space"/>,
/// and choose colorspace-dependent parameters appropriately.
/// </summary>
/// <param name="colorspace">The required colorspace.</param>
/// <remarks>See <see href="c90654b9-f3f4-4319-80d1-979c73d84e76.htm" target="_self">Special color spaces</see>,
/// below, before using this. A large number of parameters, including all per-component parameters,
/// are set by this routine; if you want to twiddle individual parameters you should call
/// <c>jpeg_set_colorspace</c> before rather than after.</remarks>
/// <seealso href="ce3f6712-3633-4a58-af07-626a4fba9ae4.htm" target="_self">Compression parameter selection</seealso>
/// <seealso href="c90654b9-f3f4-4319-80d1-979c73d84e76.htm" target="_self">Special color spaces</seealso>
public void jpeg_set_colorspace(J_COLOR_SPACE colorspace)
{
int ci;
/* Safety check to ensure start_compress not called yet. */
if (m_global_state != JpegState.CSTATE_START)
ERREXIT(J_MESSAGE_CODE.JERR_BAD_STATE, (int)m_global_state);
/* For all colorspaces, we use Q and Huff tables 0 for luminance components,
* tables 1 for chrominance components.
*/
m_jpeg_color_space = colorspace;
m_write_JFIF_header = false; /* No marker for non-JFIF colorspaces */
m_write_Adobe_marker = false; /* write no Adobe marker by default */
switch (colorspace)
{
case J_COLOR_SPACE.JCS_GRAYSCALE:
m_write_JFIF_header = true; /* Write a JFIF marker */
m_num_components = 1;
/* JFIF specifies component ID 1 */
jpeg_set_colorspace_SET_COMP(0, 1, 1, 1, 0, 0, 0);
break;
case J_COLOR_SPACE.JCS_RGB:
m_write_Adobe_marker = true; /* write Adobe marker to flag RGB */
m_num_components = 3;
jpeg_set_colorspace_SET_COMP(0, 0x52 /* 'R' */, 1, 1, 0, 0, 0);
jpeg_set_colorspace_SET_COMP(1, 0x47 /* 'G' */, 1, 1, 0, 0, 0);
jpeg_set_colorspace_SET_COMP(2, 0x42 /* 'B' */, 1, 1, 0, 0, 0);
break;
case J_COLOR_SPACE.JCS_YCbCr:
m_write_JFIF_header = true; /* Write a JFIF marker */
m_num_components = 3;
/* JFIF specifies component IDs 1,2,3 */
/* We default to 2x2 subsamples of chrominance */
jpeg_set_colorspace_SET_COMP(0, 1, 2, 2, 0, 0, 0);
jpeg_set_colorspace_SET_COMP(1, 2, 1, 1, 1, 1, 1);
jpeg_set_colorspace_SET_COMP(2, 3, 1, 1, 1, 1, 1);
break;
case J_COLOR_SPACE.JCS_CMYK:
m_write_Adobe_marker = true; /* write Adobe marker to flag CMYK */
m_num_components = 4;
jpeg_set_colorspace_SET_COMP(0, 0x43 /* 'C' */, 1, 1, 0, 0, 0);
jpeg_set_colorspace_SET_COMP(1, 0x4D /* 'M' */, 1, 1, 0, 0, 0);
jpeg_set_colorspace_SET_COMP(2, 0x59 /* 'Y' */, 1, 1, 0, 0, 0);
jpeg_set_colorspace_SET_COMP(3, 0x4B /* 'K' */, 1, 1, 0, 0, 0);
break;
case J_COLOR_SPACE.JCS_YCCK:
m_write_Adobe_marker = true; /* write Adobe marker to flag YCCK */
m_num_components = 4;
jpeg_set_colorspace_SET_COMP(0, 1, 2, 2, 0, 0, 0);
jpeg_set_colorspace_SET_COMP(1, 2, 1, 1, 1, 1, 1);
jpeg_set_colorspace_SET_COMP(2, 3, 1, 1, 1, 1, 1);
jpeg_set_colorspace_SET_COMP(3, 4, 2, 2, 0, 0, 0);
break;
case J_COLOR_SPACE.JCS_UNKNOWN:
m_num_components = m_input_components;
if (m_num_components < 1 || m_num_components > JpegConstants.MAX_COMPONENTS)
ERREXIT(J_MESSAGE_CODE.JERR_COMPONENT_COUNT, m_num_components, JpegConstants.MAX_COMPONENTS);
for (ci = 0; ci < m_num_components; ci++)
{
jpeg_set_colorspace_SET_COMP(ci, ci, 1, 1, 0, 0, 0);
}
break;
default:
ERREXIT(J_MESSAGE_CODE.JERR_BAD_J_COLORSPACE);
break;
}
}
private bool TIFFjpeg_set_colorspace(J_COLOR_SPACE colorspace)
{
try
{
m_compression.jpeg_set_colorspace(colorspace);
}
catch (Exception)
{
return false;
}
return true;
}
/// <summary>
/// Maps input color spaces to best related color space for JPEG encoding.
/// </summary>
/// <param name="in_color_space"></param>
/// <returns></returns>
public J_COLOR_SPACE map_colorspace(J_COLOR_SPACE in_color_space)
{
switch(in_color_space)
{
case J_COLOR_SPACE.JCS_GRAYSCALE:
case J_COLOR_SPACE.JCS_CMYK:
case J_COLOR_SPACE.JCS_YCCK:
case J_COLOR_SPACE.JCS_UNKNOWN:
return in_color_space;
case J_COLOR_SPACE.JCS_RGB:
case J_COLOR_SPACE.JCS_YCbCr:
return J_COLOR_SPACE.JCS_YCbCr;
}
ERREXIT(J_MESSAGE_CODE.JERR_BAD_IN_COLORSPACE);
return J_COLOR_SPACE.JCS_UNKNOWN; // Unreachable code
}
extern public static void jpeg_set_colorspace (ref jpeg_compress_struct cinfo, J_COLOR_SPACE colorspace);
static bool TIFFjpeg_set_colorspace(JPEGState sp, J_COLOR_SPACE colorspace)
{
try
{
libjpeg.jpeg_set_colorspace((jpeg_compress)sp.comm, colorspace);
}
catch
{
return false;
}
return true;
}
extern public static void jpeg_set_colorspace
(ref jpeg_compress_struct cinfo, J_COLOR_SPACE colorspace);
// Set the JPEG colorspace, and choose colorspace-dependent default values.
public static void jpeg_set_colorspace(jpeg_compress cinfo, J_COLOR_SPACE colorspace, J_SUBSAMPLING subsampling)
{
// Safety check to ensure start_compress not called yet.
if(cinfo.global_state!=STATE.CSTART) ERREXIT1(cinfo, J_MESSAGE_CODE.JERR_BAD_STATE, cinfo.global_state);
// For all colorspaces, we use Q and Huff tables 0 for luminance components,
// tables 1 for chrominance components.
cinfo.jpeg_color_space=colorspace;
cinfo.write_JFIF_header=false; // No marker for non-JFIF colorspaces
cinfo.write_Adobe_marker=false; // write no Adobe marker by default
switch(colorspace)
{
case J_COLOR_SPACE.JCS_GRAYSCALE:
cinfo.write_JFIF_header=true; // Write a JFIF marker
cinfo.num_components=1;
// JFIF specifies component ID 1
SET_COMP(cinfo, 0, 1, 1, 1, 0, 0, 0);
break;
case J_COLOR_SPACE.JCS_RGB:
cinfo.write_Adobe_marker=true; // write Adobe marker to flag RGB
cinfo.num_components=3;
SET_COMP(cinfo, 0, 0x52, 1, 1, 0, 0, 0); // 0x52 = 'R'
SET_COMP(cinfo, 1, 0x47, 1, 1, 0, 0, 0); // 0x47 = 'G'
SET_COMP(cinfo, 2, 0x42, 1, 1, 0, 0, 0); // 0x42 = 'B'
break;
case J_COLOR_SPACE.JCS_YCbCr:
cinfo.write_JFIF_header=true; // Write a JFIF marker
cinfo.num_components=3;
// JFIF specifies component IDs 1,2,3
if(cinfo.lossless||subsampling==J_SUBSAMPLING.JPEG444)
{
SET_COMP(cinfo, 0, 1, 1, 1, 0, 0, 0);
SET_COMP(cinfo, 1, 2, 1, 1, 1, 1, 1);
SET_COMP(cinfo, 2, 3, 1, 1, 1, 1, 1);
}
else if(subsampling==J_SUBSAMPLING.JPEG422)
{
// We default to 2x1 subsamples of chrominance
SET_COMP(cinfo, 0, 1, 2, 1, 0, 0, 0);
SET_COMP(cinfo, 1, 2, 1, 1, 1, 1, 1);
SET_COMP(cinfo, 2, 3, 1, 1, 1, 1, 1);
}
else
{
// We default to 2x2 subsamples of chrominance
SET_COMP(cinfo, 0, 1, 2, 2, 0, 0, 0);
SET_COMP(cinfo, 1, 2, 1, 1, 1, 1, 1);
SET_COMP(cinfo, 2, 3, 1, 1, 1, 1, 1);
}
break;
case J_COLOR_SPACE.JCS_CMYK:
cinfo.write_Adobe_marker=true; // write Adobe marker to flag CMYK
cinfo.num_components=4;
SET_COMP(cinfo, 0, 0x43, 1, 1, 0, 0, 0); // 0x43 = 'C'
SET_COMP(cinfo, 1, 0x4D, 1, 1, 0, 0, 0); // 0x4D = 'M'
SET_COMP(cinfo, 2, 0x59, 1, 1, 0, 0, 0); // 0x59 = 'Y'
SET_COMP(cinfo, 3, 0x4B, 1, 1, 0, 0, 0); // 0x4B = 'K'
break;
case J_COLOR_SPACE.JCS_YCCK:
cinfo.write_Adobe_marker=true; // write Adobe marker to flag YCCK
cinfo.num_components=4;
if(cinfo.lossless)
{
SET_COMP(cinfo, 0, 1, 1, 1, 0, 0, 0);
SET_COMP(cinfo, 1, 2, 1, 1, 1, 1, 1);
SET_COMP(cinfo, 2, 3, 1, 1, 1, 1, 1);
SET_COMP(cinfo, 3, 4, 1, 1, 0, 0, 0);
}
else
{
SET_COMP(cinfo, 0, 1, 2, 2, 0, 0, 0);
SET_COMP(cinfo, 1, 2, 1, 1, 1, 1, 1);
SET_COMP(cinfo, 2, 3, 1, 1, 1, 1, 1);
SET_COMP(cinfo, 3, 4, 2, 2, 0, 0, 0);
}
break;
case J_COLOR_SPACE.JCS_UNKNOWN:
cinfo.num_components=cinfo.input_components;
if(cinfo.num_components<1||cinfo.num_components>MAX_COMPONENTS) ERREXIT2(cinfo, J_MESSAGE_CODE.JERR_COMPONENT_COUNT, cinfo.num_components, MAX_COMPONENTS);
for(int ci=0; ci<cinfo.num_components; ci++) SET_COMP(cinfo, ci, ci, 1, 1, 0, 0, 0);
break;
default: ERREXIT(cinfo, J_MESSAGE_CODE.JERR_BAD_J_COLORSPACE); break;
}
}
// Set the JPEG colorspace, and choose colorspace-dependent default values.
public static void jpeg_set_colorspace(jpeg_compress cinfo, J_COLOR_SPACE colorspace)
{
jpeg_set_colorspace(cinfo, colorspace, J_SUBSAMPLING.JPEG420);
}
// Set the JPEG colorspace, and choose colorspace-dependent default values.
public static void jpeg_set_colorspace(jpeg_compress cinfo, J_COLOR_SPACE colorspace, J_SUBSAMPLING subsampling)
{
// Safety check to ensure start_compress not called yet.
if (cinfo.global_state != STATE.CSTART)
{
ERREXIT1(cinfo, J_MESSAGE_CODE.JERR_BAD_STATE, cinfo.global_state);
}
// For all colorspaces, we use Q and Huff tables 0 for luminance components,
// tables 1 for chrominance components.
cinfo.jpeg_color_space = colorspace;
cinfo.write_JFIF_header = false; // No marker for non-JFIF colorspaces
cinfo.write_Adobe_marker = false; // write no Adobe marker by default
switch (colorspace)
{
case J_COLOR_SPACE.JCS_GRAYSCALE:
cinfo.write_JFIF_header = true; // Write a JFIF marker
cinfo.num_components = 1;
// JFIF specifies component ID 1
SET_COMP(cinfo, 0, 1, 1, 1, 0, 0, 0);
break;
case J_COLOR_SPACE.JCS_RGB:
cinfo.write_Adobe_marker = true; // write Adobe marker to flag RGB
cinfo.num_components = 3;
SET_COMP(cinfo, 0, 0x52, 1, 1, 0, 0, 0); // 0x52 = 'R'
SET_COMP(cinfo, 1, 0x47, 1, 1, 0, 0, 0); // 0x47 = 'G'
SET_COMP(cinfo, 2, 0x42, 1, 1, 0, 0, 0); // 0x42 = 'B'
break;
case J_COLOR_SPACE.JCS_YCbCr:
cinfo.write_JFIF_header = true; // Write a JFIF marker
cinfo.num_components = 3;
// JFIF specifies component IDs 1,2,3
if (cinfo.lossless || subsampling == J_SUBSAMPLING.JPEG444)
{
SET_COMP(cinfo, 0, 1, 1, 1, 0, 0, 0);
SET_COMP(cinfo, 1, 2, 1, 1, 1, 1, 1);
SET_COMP(cinfo, 2, 3, 1, 1, 1, 1, 1);
}
else if (subsampling == J_SUBSAMPLING.JPEG422)
{
// We default to 2x1 subsamples of chrominance
SET_COMP(cinfo, 0, 1, 2, 1, 0, 0, 0);
SET_COMP(cinfo, 1, 2, 1, 1, 1, 1, 1);
SET_COMP(cinfo, 2, 3, 1, 1, 1, 1, 1);
}
else
{
// We default to 2x2 subsamples of chrominance
SET_COMP(cinfo, 0, 1, 2, 2, 0, 0, 0);
SET_COMP(cinfo, 1, 2, 1, 1, 1, 1, 1);
SET_COMP(cinfo, 2, 3, 1, 1, 1, 1, 1);
}
break;
case J_COLOR_SPACE.JCS_CMYK:
cinfo.write_Adobe_marker = true; // write Adobe marker to flag CMYK
cinfo.num_components = 4;
SET_COMP(cinfo, 0, 0x43, 1, 1, 0, 0, 0); // 0x43 = 'C'
SET_COMP(cinfo, 1, 0x4D, 1, 1, 0, 0, 0); // 0x4D = 'M'
SET_COMP(cinfo, 2, 0x59, 1, 1, 0, 0, 0); // 0x59 = 'Y'
SET_COMP(cinfo, 3, 0x4B, 1, 1, 0, 0, 0); // 0x4B = 'K'
break;
case J_COLOR_SPACE.JCS_YCCK:
cinfo.write_Adobe_marker = true; // write Adobe marker to flag YCCK
cinfo.num_components = 4;
if (cinfo.lossless)
{
SET_COMP(cinfo, 0, 1, 1, 1, 0, 0, 0);
SET_COMP(cinfo, 1, 2, 1, 1, 1, 1, 1);
SET_COMP(cinfo, 2, 3, 1, 1, 1, 1, 1);
SET_COMP(cinfo, 3, 4, 1, 1, 0, 0, 0);
}
else
{
SET_COMP(cinfo, 0, 1, 2, 2, 0, 0, 0);
SET_COMP(cinfo, 1, 2, 1, 1, 1, 1, 1);
SET_COMP(cinfo, 2, 3, 1, 1, 1, 1, 1);
SET_COMP(cinfo, 3, 4, 2, 2, 0, 0, 0);
}
break;
case J_COLOR_SPACE.JCS_UNKNOWN:
cinfo.num_components = cinfo.input_components;
if (cinfo.num_components < 1 || cinfo.num_components > MAX_COMPONENTS)
{
ERREXIT2(cinfo, J_MESSAGE_CODE.JERR_COMPONENT_COUNT, cinfo.num_components, MAX_COMPONENTS);
}
for (int ci = 0; ci < cinfo.num_components; ci++)
{
SET_COMP(cinfo, ci, ci, 1, 1, 0, 0, 0);
}
break;
default: ERREXIT(cinfo, J_MESSAGE_CODE.JERR_BAD_J_COLORSPACE); break;
}
}
// Set the JPEG colorspace, and choose colorspace-dependent default values.
public static void jpeg_set_colorspace(jpeg_compress cinfo, J_COLOR_SPACE colorspace)
{
jpeg_set_colorspace(cinfo, colorspace, J_SUBSAMPLING.JPEG420);
}
