Image.GetThumbnailImage is slow!

Question

User-1785506111 posted

I'm trying to create an image generation program.  I can create very large images on the fly relatively quick.  By quick I mean around .5 seconds per image.  However, when I try to use the GetThumbnailImage routine or try to draw to another image from the original image, it takes a very long time (~1.5 - 2.0 seconds each).  Does anyone know why this is?  Also, is there a technique to make this faster?

Note that I have tried adjusting several attributes of the image from dpi, overall size, antialiasing options, etc and setting them from very high settings to very low quality settings and have notice neglible impact.  At best I saw around a couple tenths of a second difference which leads me to believe the Image object itself could be the problem.

Thanks for any feedback.

Answer 1

User-1573135047 posted

How quick are you expecting it?  It needs to resize the original image to thumbnail size.

Answer 2

User-1785506111 posted

I realize this.  But I can open up photoshop and resize a gargantuan picture down to just a couple hundred pixels in about as long as it takes me to click the button.  I realize in the case of photoshop the image sits in that program's own memory space but I could think that on very fast machines this should happen, well, very quickly (less than one second).  It was happening very slowly on my quad core machine that had DDR3 ram.  That just doesn't seem right.  So, I was asking if anyone had alternate methods for generating thumbnails other than the GetThumbnailImage method.  I'm toying with the idea of just using the first Graphics object to just output a smaller image instead of forcing the Framework to fire up a second Graphics object that has to read the memory space of the first.  That could make it faster. /rubschin

Answer 3

User-1785506111 posted

I should also point out that if I got this to work as quickly as I'm wanting it'd be used in a server/client envrionment and need to respond to potentially thousands of requests.  That's the reason behind my complaint.  Perhaps the Drawing namespaces weren't meant for high speed image creation.  I admit this may be so.  But, if possible, I'd like to see if it can be used for such.