Next LUG meet: 12 Oct 2003 around 4 pm - VJTI Computer Centre
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Hi Friends,
I have to manipulate ( rotate ) a tiff file having 5600 x 6600
pixels.
For that I created a pixbuf from file
Glib::RefPtr<Gdk::Pixbuf> m_ppixBuf;
m_ppixBuf = Gdk::Pixbuf::create_from_file(filename );
int lHeight = m_ppixBuf->get_height();
int lWidth = m_ppixBuf->get_width();
int lRotatedRowStride = m_ppixBuf->get_rowstride();
Then collected data in a local variable,
gchar* pixdata = m_ppixBuf->get_pixels();
Allocating equivalent memory to one temporary variable
gchar* tmpdata = (char *) malloc( lHeight * lWidth *
lNo_of_channels);
Then coying pixels one by one from source to target using memcpy
function.
// case 90 degree :
for(j = 0, k = (lHeight-1); j < lHeight; j++, k--)
{
for(i = 0; i < lWidth; i++)
{
memcpy(&tmpmap[i * lRotatedRowStride + k *
iNo_of_Channel], &bitmap[j * lRowstride + i * iNo_of_Channel],
iNo_of_Channel);
}
}
This code works fine , but takes lot of time to rotate large image.
Is there any other way to make this operation faster?
Also I want to save modified pixbuf in "tiff" file, but GDK library
allows me to save only in PNG and JPEG format.
How will I save it in tiff format?
If anyone knows please help me.
Thanks,
Ramachandra
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