Fixed Poor quality cover image upload

[Optic]

Hello @Nobita ,

I've noticed that the cover image after upload and crop is poor quality (jagged lines) recently.

For example, I upload this high quality image:


Then upload it as cover and crop.

But then the result is this: (1024x350)


Notice how the lines are really jagged and bad.


I cannot get the nice quality cover resize image you have on your example Group here:
http://nobita.me/groups/DragonBall/

(also notice your crop image is larger - 1440x449)



Has something changed in the last few versions? Any other settings to adjust image quality/crop? I don't remember the quality being this poor.


My quality is set to 100:


I also tried switching to ImageMagick for attachment thumbnails but no difference (I think maybe you're using a different module).

Any help would greatly be appreciated.

 

[Truonglv]

It is as expected in the latest version. My site use the old method (it is include some bugs) so the resize demension is higher 1024 * 350.

 

[Optic]

OK, but resize dimension is not the issue... the resize quality is the problem, I got same result on your site now:



If I manually resize and crop in Photoshop using Bicubic resize algorithm, lines are much smoother:



I can reproduce the jagged line artifacts in Photoshop if I use Nearest Neighbour resize algorithm (which looks poor):





Can you please investigate your cover image resize algorithm to see if you can fix this quality issue?

If possible we need Bicubic or Lanczos resize algorithm for best quality resize.

 

[Truonglv]

Well. Look like I must change some algorithm for this.

 

[Truonglv]

New plugin was used and seem it is better now

 

[Optic]

Thanks for the update @Nobita

Is this fix in current 2.5.7a ? Or in next release?

 

[Truonglv]

Thanks for the update @Nobita

Is this fix in current 2.5.7a ? Or in next release?

Optic2.5.8

 

[Rehenna Usma]

Thanks for the update @Nobita

 

[localhost]

2016 thread ohhh what a year!