A mystery 300px image size

Question

I wonder if you can help me track down why all my images are being cropped to a 300px size that I've not specified anywhere at all. I know from some digging in the past that WordPress introduced a default size of 768px and basically hid it from us, now I'm wondering if they (or WooCommerce - this is a WooCommerce site) also have a hidden size of 300px.

That 768px size was called medium_large and you would unset it like so:

function mytheme_filter_image_sizes($sizes) {  
    unset( $sizes[ 'medium_large' ] );
    return $sizes;
}
add_filter('intermediate_image_sizes_advanced', 'mytheme_filter_image_sizes' ); 

Has anyone come across this extra 300px image and how did you unset it? Googling this has proved useless.

Here's my code for the image sizes being used in this theme:

add_theme_support( 'post-thumbnails' );

// Set our preferred default image sizes
set_post_thumbnail_size( 960, 960, true );

update_option( 'thumbnail_size_w', 240 );
update_option( 'thumbnail_size_h', 240 );
update_option( 'thumbnail_crop', 1 );
update_option( 'medium_size_w', 720 );
update_option( 'medium_size_h', 720 );
update_option( 'large_size_w', 1440 );
update_option( 'large_size_h', 1440 );

// Custom new sizes for the srcset
add_image_size( 'mytheme-hd-img', 1920, 1920);
add_image_size( 'mytheme-epic-img', 2400, 2400);

And for WooCommerece:

$catalog = array(
    'width'     => '360',
    'height'    => '360',
    'crop'      => 1        // true
);
$single = array(
    'width'     => '720',
    'height'    => '720',
    'crop'      => 0        // false
);
$thumbnail = array(
    'width'     => '240',
    'height'    => '240',
    'crop'      => 1        // true
);
// Image sizes
update_option( 'shop_catalog_image_size', $catalog );
update_option( 'shop_single_image_size', $single );
update_option( 'shop_thumbnail_image_size', $thumbnail );

Answer 1

Updated Answer

After doing more testing, the 300px size only gets generated when I have the official WooCommerce Brands plugin activated.

So 300px is the default WooCommerce image size when the standard sizes go undefined. See wc_get_image_size() in \includes\wc-core-functions.php.

It seems that at some point WC must have filled in the blank of a missing size and that setting got used.

My temporary solution is to deactivate the WooCommerce Brands plugin. Obviously this isn't viable so I may have to report this bug...

Bug has been reported.

I talked with WooCommerce support and they've been able to replicate the issue and have created a bug report.

Answer 2

I work for WooCommerce - just wanted to give everyone a heads up that this has been reported. While I don't have an ETA on the fix, I'll try to post here if it's timely (don't want to resurrect dead threads), but keep an eye on the Brands Changelog just in case.

Thanks for bringing it up! :)

UPDATE: December 13, 2017

So after our dev team looked through this, it's actually added by design. The 300px image is used for the Brand listing pages and functions associated with that, which is built for 300px images.

Although that means it's not considered a "bug", it's something that could certainly be improved. I'll look into adding an image display setting that would allow you to change the size of the brand image that's used. Keep an eye on the changelog - hopefully I'll be able to get something through (once I eventually find a few minutes to code).