Thumbnails Generation Is Slow when Using Aspose.Slides for Java

Hi,
in a specific power point file with only 1 simple slide, conversion is really slow, about 30 to 40 seconds!
other files i’ve worked with took only 15 seconds to process the first slides and later slides were much faster to process.

both lines below works slowly:

Presentation pre = new Presentation('slow.pptx');

BufferedImage image = pre.getSlides().get_Item(0).getThumbnail(500, 500);

you may find the sample file here:

would be nice to know what’s causes the slowness so i could disable it from power point itself until a fix is released.

@roeycohen5,

I have worked with source file shared by you using Aspose.Slides for Java 18.10 in windows 10 environment and unable to observe issue. I also like to inform that it took 3 seconds to load file on my end. Can you please share environment details along with which Aspose.Slides version you are using on your end so that we may further investigate to help you out.

Hi,
I’ve made some measures,

new Presentation() - takes about 2-3 seconds.

getThumbnail() time increases dramatically when the scale factor increases.
try in your code running getThumbnail(3, 3) - you’ll see how the time goes from 0.5 a sec to almost 30 seconds (at least on my I7 CPU / windows 10 machine).

removing the background makes a big difference and removing the text goes all the way to 0.5.

is it possible to reduce quality of the conversion or use a different java graphics library that works faster?

one more thing, i see that the mirroring effect of the main title is not visible in the output image.

Roey

@roeycohen5,

I have worked with source file and code snippet shared by you using Aspose.Slides for Java 18.10 and have been able to observe issues. An issue with ID SLIDESJAVA-37396 for slow conversion and an issue with ID SLIDESJAVA-37397 for mirror effect issue has been created in our issue tracking system to further investigate and resolve the issues. This thread has been linked with the issues so that you may be automatically notified once the issues will be fixed.

The issues you have found earlier (filed as SLIDESJAVA-37396) have been fixed in this update.

The issues you have found earlier (filed as SLIDESJAVA-37397) have been fixed in this update.