Thumbnail Quality Is Terrible

Hmmm… I thought the quality was reasonably good, but an option to set the quality would be nice.

What I’m missing is an option to set to which image to link: the medium format image or the largest image. And an option to automatically delete the largest image when a medium image has been created.

I’m also surprised about this. I’m not even sure if the plugin I’ve had to use to adjust quality will continue to work with 2.5.

This should be a default feature.

I’ve added this to the WordPress 2.6 roadmap:

https://trac.www.ads-software.com/ticket/6289

Maybe it’ll be reassigned to a 2.5.x build once one actually exists in the tracking system (it won’t until 2.5 is out).

For those interested,

Location:
/wp-includes/media.php

On Line 178, Find:
$jpeg_quality=75

Replace with
$jpeg_quality=##

Where ## = a number greater than 75, and to a maximum of 100.

Please note, while this will increase the default quality of thumbnails, the file sizes will be bigger. However, for anyone that cares about quality images on their blogs, you won’t mind the trade-off. The default quality of the generated thumbs, on a hi-res monitor, are just atrocious. At least this gives you a chance to have presentable thumbnails. Use at your own risk, and make a backup of the original before editing core files.

An Ideal Solution
——————–
What would be an ideal solution is to let users choose if they’d like to use imagemagick or the default options. This would let users with imagemagick installed on their servers to specify the switches to apply sharpness, radius, contrast, etc on a single default variable string, as an Admin Option. This would produce superior thumbs, and, more importantly, give WP users a choice. But at the very least, allow users to specify a quality variable on the default options. 75 is simply inadequate to produce acceptable quality thumbnails.

Please Also Note
———————
Please do not suggest I use a plugin to address the quality issue. I’m interested in WordPress improving THEIR inherent image quality routines/options rather than forcing people to rely on plugins to address a [lack of] quality issue that they include as a default.

Thanks for that rongo! Exactly what I was looking for ??

Saved the rest of my day! I’ve been looking for this several hours now. Thx!

Maybe it’s just me, but the thumbnail quality of what I’ve used on 2.5 appears to be a good balance between file-size and quality…

I agree it wouldn’t be a bad idea to make this a variable in the admin panel, nor would it be all that difficult to do looking at the panel itself…

The jpeg_quality is set to 90 in the latest trunk, and it’s also filtered so you can change it with a plugin. In fact, it looks like a plugin has a lot of possible hooks here, giving a wide range of potential control.

Fine tuning options for these settings are definitely plugin territory. I think most people will be happy with the current defaults.

90 is great. thx guys!

Otto, Do you know if you can change things like resample methods (bicubic, bilinear, etc) as well as sharpening with a plugin?

Also, can you take a look at my post here:
https://www.ads-software.com/support/topic/166977?replies=7

and tell me if this is something automattic might look at in the near future, or if we need to rely on a plugin for an intuitive image control such as this?

hi

i like to ask. how should i go about configuring it so that when the thumbnail is being crop, it crop from the top-down and not the central area?

please advice. thanks alot

Hey, I wanna say that while this is all well and good, WordPress also kills the colors in my photos. And that changing the quality from 90 to 100 didn’t actually help much.
Any ideas? Any other hidden numbers I need to max out?

Don’t use value of 100 – this is the most inefficient JPEG compression possible! With 100 your thumbnail size will be several times larger with minimal visual improvement. For example on dog disease website , In order to keep file size small and quality good enough – use values between 85 and 90.