Image Optim

[Ocean West]

Here is a tip...

https://imageoptim.com

A free tool that will help optimize the default images in the distribution of v4

When I ran it on a fresh RC5 folder it reported:

48.7kb out of 251.4kb 
29.1% per file on average (up to 84.4%)

kudos to the team for how original files were pretty optimized already. 

every byte helps...

[Gnuru]

I used

find -type f -name "*.jpg" -exec jpegoptim --max=75 --strip-all {} \;

per ssh on my linux VPS.

Google pagespeed is pleased ....

[ASTRAPI]

--max=75 parameter disables lossless optimization mode and the quality of your images will be drop 25% and they will be not as the original ones so you may test it before you use it on your live forums images

[Makoto]

--max=75 parameter disables lossless optimization mode and the quality of your images will be drop 25% and they will be not as the original ones so you may test it before you use it on your live forums images

​No, it means that jpeg images saved with a quality setting >=75% will be re-compressed at said max level, while all other images will be ignored. It does not "drop the quality of your images by 25%", that's not how it works.

There's generally no reason to run that unless you've lowered the jpeg quality setting of images in your AdminCP and want to re-compress your currently uploaded images. You should also probably make a backup of your files before running any commands like that regardless.

[ASTRAPI]

       -m[0..100], --max=[0..100]
             Sets   the   maximum  image  quality  factor  (disables  lossless
             optimization mode, which is by default enabled). This option will
             reduce quality of those source files that were saved using higher
             quality setting.  While files that  already  have  lower  quality
             setting  will  be  compressed  using  the  lossless  optimization
             method.

[Makoto]

Sigh. Reading comprehension is an important skill to use, you know. Please, really, stop copy and pasting things without having an understanding of what you're talking about. It just creates unnecessary confusion and misinformation to those seeking help here.

       -m[0..100], --max=[0..100]
             Sets   the   maximum  image  quality  factor  (disables  lossless
             optimization mode, which is by default enabled). This option will
             reduce quality of those source files that were saved using higher
             quality setting.  While files that  already  have  lower  quality
             setting  will  be  compressed  using  the  lossless  optimization
             method.​

I posted a bit about this in another thread here also,

As far as optimizing images, some of these tools have varying definitions of "optimize", re-compressing jpegs to lower quality settings is not "optimizing" as far as I'm concerned, it's just reducing quality. The quality setting you use for your websites lossy images is a matter of opinion and not a strict recommendation you need to adhere to, though there's generally not much benefit compressing images at a quality setting above 90.

Actual image optimization that does not involve lowering the quality of your images includes stripping metadata from jpeg images and utilizing tools such as OptiPNG to re-compress lossless PNG's (which can potentially significantly reduce the filesize of some images).

Restricting images to a quality setting of 75% is pretty low and I personally would not recommend doing that unless you're really constrained on space or bandwidth. I consider 85 to be a good balance between file size and quality, but when quality is particularly important I'll up this to 87-90. Anything above 90-93 generally results in exponential file growth with very diminished returns.