DPX saving is slow

[aziwoqpd]

After upgrading from 6.3.5-3 to 6.4.1-5, saving DPX files has become almost 10 times slower! All of the other file formats I use seem to still be the same speed, though. Has something changed recently?

Here's a sample program:

Code: Select all

int main()
{
	Magick::InitializeMagick( NULL );
	Magick::Image img( Magick::Geometry( 2048, 1556 ), Magick::ColorGray( 0 ) );
	img.depth( 10 );
	img.addNoise(Magick::GaussianNoise);
	time_t ttt = time( NULL );
	for( int c=0 ; c<50 ; c++ ) {
		std::stringstream sss;
		sss << "test";
		sss << c;
		sss << ".dpx";
		img.write( sss.str() );
	}
	printf( "%d\n", time(NULL)-ttt );
	return 0;
}

For Imagemagick 6.3.5-3 this takes 5 seconds. With Imagemagick 6.4.1-5 it takes 41 seconds. I'm using the Windows build, if it makes a difference.

[fmw42]

I am having trouble with long delays in converting to GIF. Anyone else?

see viewtopic.php?f=3&t=11388

[magick]

Timing tests show the majority of the time is spent generating noise. We will have a patch for this problem within the next few days. Thanks.

[aziwoqpd]

Sorry, the timing for the above is excluding the noise generation. I just added that in when I was testing something with compressed files and forgot to remove it. The large difference in speed remains even if you remove the noise generation.

[magick]

We're still investigating but our initial test under Redhat Linux shows that ImageMagick 6.3.5 is slightly slower (19 seconds to write 50 DPX images) than 6.4.1-5 (17 seconds). We'll try the timing under Windows in the next few days.