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From J.P. Delport, "attached a modified jpeg plugin that allows writing of grayscale images."

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This commit is contained in:
Robert Osfield
2009-07-17 07:50:06 +00:00
parent 315e749cce
commit 2bed6a2dca
1 changed files with 28 additions and 6 deletions
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34
src/osgPlugins/jpeg/ReaderWriterJPEG.cpp
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@@ -619,12 +619,34 @@ int *numComponents_ret)
class ReaderWriterJPEG : public osgDB::ReaderWriter
{
WriteResult::WriteStatus write_JPEG_file (std::ostream &fout,int image_width,int image_height,JSAMPLE* image_buffer,int quality = 100) const
WriteResult::WriteStatus write_JPEG_file (std::ostream &fout, const osg::Image &img, int quality = 100) const
{
int image_width = img.s();
int image_height = img.t();
if ( (image_width == 0) || (image_height == 0) )
return WriteResult::ERROR_IN_WRITING_FILE;
J_COLOR_SPACE image_color_space = JCS_RGB;
int image_components = 3;
// Only cater for gray, alpha and RGB for now
switch(img.getPixelFormat()) {
case(GL_LUMINANCE):
case(GL_ALPHA): {
image_color_space = JCS_GRAYSCALE;
image_components = 1;
break;
}
case(GL_RGB): {
image_color_space = JCS_RGB;
image_components = 3;
break;
}
default: return WriteResult::ERROR_IN_WRITING_FILE; break;
}
JSAMPLE* image_buffer = (JSAMPLE*)(img.data());
/* This struct contains the JPEG compression parameters and pointers to
* working space (which is allocated as needed by the JPEG library).
* It is possible to have several such structures, representing multiple
@@ -680,8 +702,8 @@ class ReaderWriterJPEG : public osgDB::ReaderWriter
*/
cinfo.image_width = image_width; /* image width and height, in pixels */
cinfo.image_height = image_height;
cinfo.input_components = 3; /* # of color components per pixel */
cinfo.in_color_space = JCS_RGB; /* colorspace of input image */
cinfo.input_components = image_components; /* # of color components per pixel */
cinfo.in_color_space = image_color_space; /* colorspace of input image */
/* Now use the library's routine to set default compression parameters.
* (You must set at least cinfo.in_color_space before calling this,
* since the defaults depend on the source color space.)
@@ -707,7 +729,7 @@ class ReaderWriterJPEG : public osgDB::ReaderWriter
* To keep things simple, we pass one scanline per call; you can pass
* more if you wish, though.
*/
row_stride = image_width * 3; /* JSAMPLEs per row in image_buffer */
row_stride = image_width * image_components; /* JSAMPLEs per row in image_buffer */
while (cinfo.next_scanline < cinfo.image_height)
{
@@ -833,7 +855,7 @@ class ReaderWriterJPEG : public osgDB::ReaderWriter
{
osg::ref_ptr<osg::Image> tmp_img = new osg::Image(img);
tmp_img->flipVertical();
WriteResult::WriteStatus ws = write_JPEG_file(fout,img.s(),img.t(),(JSAMPLE*)(tmp_img->data()),getQuality(options));
WriteResult::WriteStatus ws = write_JPEG_file(fout, *(tmp_img.get()), getQuality(options));
return ws;
}