performance: Whats the fastest way to resize and resample?

[daniel]

Hello again,

i'm testing XnView, GD lib (PHP bundle) and ImageMagick. Due to the large file format compatibility of XnView and ImageMagick i'm doing some benchmarks on them.
I found out that XnView ist much faster in average but has a lost in color acurancy. But this is not the point.
I was wondering, if I could speed things up by using the -rtype quick flag when resizing. It turned out to be even much slower.
My aim is just creating really (and i mean really) fast thumbnails (well, width of 400px) where quality is not very important.
I'm having JPEGs of any size going up to 30MB, which takes far more than 60secs (my limiter).
Now i'm using:

Code: Select all

nconvert -out png -o output_image.png -ratio -resize 400 0 input_image.jpg

I've tried:

Code: Select all

nconvert -out png -o output_image.png -ratio -rtype quick -resize 400 0 input_image.jpg

which is even slower.
Any idea how to speed things up?

[xnview]

Now i'm using:

Code: Select all

nconvert -out png -o output_image.png -ratio -resize 400 0 input_image.jpg

I've tried:

Code: Select all

nconvert -out png -o output_image.png -ratio -rtype quick -resize 400 0 input_image.jpg

which is even slower.
Any idea how to speed things up?

Strange that quick is slower, but the process can be quicker if i add a thumb_size as option. For jpeg it is better to load on the fly a reduced picture (as xnview).

[daniel]

How does that work?
Do I add -thumb_size to my command? I couldn't find the thumb_size as a parameter listed with the -help flag. Where do I put it? Is this documented anywhere?

[xnview]

How does that work?
Do I add -thumb_size to my command? I couldn't find the thumb_size as a parameter listed with the -help flag. Where do I put it? Is this documented anywhere?

No i means if i add this command... Currently there is no such option...

[daniel]

ah, i understand
well would definetly be nice to have. Due to your fast resizing capabilities nconvert might have a big future in the web server business. If you get the last edge of performance out of it, especially concerning thumbnails generating, this gonna be the way to go.

[xnview]

ah, i understand
well would definetly be nice to have. Due to your fast resizing capabilities nconvert might have a big future in the web server business. If you get the last edge of performance out of it, especially concerning thumbnails generating, this gonna be the way to go.

Could you send me an email or PM, i would like to send you a test version...

[Arvind]

Hi,
Is this thumb size option implemented in higher versions of nConvert?
If yes, how do you use it?
Could you explain with an example?

Thanks
arvind