poor feature image resolution

Your theory is right, but technic is making some twists in it. As a consequence shrinking an image does not automatically mean a sharper picture. If your image was 960 pixel wide, you can shrink it to 480 pixel wide in a good quality because 960/2=480. So there will be only whole pixels in the smaller image. You mentioned the new image has a width of only 895 pixels. So take a look: 960/895=1,0726. There is no way to render fractions of pixels so the width of the image will be rounded up or down to a whole number of pixels. This means that most shrinked images show some distorsion. In most cases it manifests in loosing sharpness just as you mention in your case. Try to resize the image in such a way that no fractionated pixels will get involved (do some math before) or crop the original image properly before resizing.

In addition PHP servers use GD library for image manipulation as default. With it’s default settings the manipulated pictures tend to loose on sharpness. Try to use an image magick-plugin if your server supports it, you will get way better images.

Hi Summoner,

Thank you for your reply. I guess you are right. I shall test it out as soon as i can. One thing I don’t quite understand on the “crop the original image properly before resizing.” Care to elaborate further?

Also, I notice the Magick Plugin hasn’t been updated for years. So I guess I will pass on this one.

Cheers!
mike

As regarding the Image Magick plugin it runs on my sites with WP 3.9 without any problem. But it needs imagick module installed on the php server.

Under “crop the original image properly before resizing” i mean the following: If you know exactly how wide the image should be in the new layout of your site, then you could crop the originally uploaded image (in photoshop for example) so that it will have a width and height, that is dividable by the number of the targeted image width without any remaining fractionated pixels (applies even to image height). This way the resized and shrinked picture can have the best possible quality. However this method can be really time consuming because you have to do some maths & cropping with all the previously uploaded images.

That is why design and layout really matters and image issues may arise if you change design.

Since last time i examined the page you linked in. The following file is used as featured image: https://mikeshouts.com/wp-content/uploads/2014/04/DeLorme-inReach-Explorer-Satellite-Communicator-672×372.jpg
If you take a look this picture has a lot of jpeg artifacts and fine details are just washed out.

As your content area is wider than 672 pixels, this image will get even scaled up to fit the content area. This leads to further loss on sharpness.

(While the originally uploaded and unmodified picture seems ok for me)

Can you just revert back to your original theme for a few minutes and check exactly which file is used in that case?

My advice is to check if your server has imagick module installed. If so then install the image magick plugin for wordpress and set the compression quality to at least 90% in the plugin settings.

If your server lacks imagick module, then you can only stay on GD-library. In this case you should set compression quality of GD-library at least to 95% in the functions.php of your theme.

In each case you should then regenerate all the picture sizes of the uploaded images with a suitable plugin. Chances are high that you will be satisfied with the image quality after this procedure, but datasize of your images will be larger, taking more time to load your site. That is the trade-off for quality pictures.

Hi summoner,

“As your content area is wider than 672 pixels, this image will get even scaled up to fit the content area. This leads to further loss on sharpness.”

this is the part that i don’t understand. why the theme is taking it as 672 when i have uploaded a full size image? i am just checking if my server has image magick installed. i am not particular adept at host kind of thing, so i am letting them to advice me.

“Can you just revert back to your original theme for a few minutes and check exactly which file is used in that case?”

what do mean which file? as in the exact file the theme is using? i am really stumped here.

I’m currently reworking this option from using CSS to using a function that actually adjusts the set_post_thumbnail_size() and the add_image_size( 'twentyfourteen-full-width' ) functions.

This means you’ll be able to control both the height and width values of both functions giving you greater control on what sizes the images are cropped at.

Will update the plugin as soon as I’m done testing it out fully ??

Regards,
Zulf

Thanks Zulf. Will be looking forward to what it can do.

Will this resolve the image quality issue?

Thanks!

Was the issue fixed with this weeks release? I still experience poor resolution due to scale up.

I’ve enabled:
– full with single post | 672px × 372px (scaled to 1.038px × 572px)
– BelowMenu FullWidth slider | 1.038px × 576px (scaled to 1.260px × 572px)

In both cases, images are scaled up ??

Looking forward to a fix.

Nope. I guess not. Still waiting to here from the developer. Can’t wait to have it fixed cos’ it is really an eyesore.

Any news on the issue? The last post is from 7 month ago. The issue still appears at least on my blog making it look rather s***ty.

Thanks for the heads up!

Does anyone still care for this bug? Any solution highly appreciated.