// 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, 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;
}
}
