Cropping Post Thumbnails from Top instead of Center in WordPress

editor-gd.php

<?php

class Unknown_Crop_Top_Center_Editor extends WP_Image_Editor_GD {

	/**
	 * Processes current image and saves to disk
	 * multiple sizes from single source.
	 *
	 * @since 3.5.0
	 * @access public
	 *
	 * @param array $sizes { {'width'=>int, 'height'=>int, 'crop'=>bool}, ... }
	 * @return array
	 */
	public function multi_resize( $sizes ) {
		$metadata = array();
		$orig_size = $this->size;

		foreach ( $sizes as $size => $size_data ) {
			if( 'thumbnail' == $size && $size_data['crop'] ) {
				$image = $this->_crop_top_center( $size_data['width'], $size_data['height'] );
			}
			else {
				$image = $this->_resize( $size_data['width'], $size_data['height'], $size_data['crop'] );
			}

			if( ! is_wp_error( $image ) ) {
				$resized = $this->_save( $image );

				imagedestroy( $image );

				if ( ! is_wp_error( $resized ) && $resized ) {
					unset( $resized['path'] );
					$metadata[$size] = $resized;
				}
			}

			$this->size = $orig_size;
		}

		return $metadata;
	}

	protected function _crop_top_center( $max_w, $max_h ) {
		$dims = image_resize_dimensions( $this->size['width'], $this->size['height'], $max_w, $max_h, true );
		if ( ! $dims ) {
			return new WP_Error( 'error_getting_dimensions', __('Could not calculate resized image dimensions'), $this->file );
		}
		list( $dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h ) = $dims;

		//crop from top
		$src_y = 0;

		$resized = wp_imagecreatetruecolor( $dst_w, $dst_h );
		imagecopyresampled( $resized, $this->image, $dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h );

		if ( is_resource( $resized ) ) {
			$this->update_size( $dst_w, $dst_h );
			return $resized;
		}

		return new WP_Error( 'image_resize_error', __('Image resize failed.'), $this->file );
	}
}

unknown-crop-top-center.php

<?php

class Unknown_Crop_Top_Center {
	
	public function __construct() {
		add_filter( 'wp_image_editors', array( $this, 'wp_image_editors' ), 100 );
	}

	public function wp_image_editors( $editors ) {
		include_once 'editor-gd.php';

		$editors2 = array(
			'Unknown_Crop_Top_Center_Editor',
		);

		$editors = array_merge( $editors2, $editors );

		return $editors;
	}
}

new Marko_Crop_Top_Center;

Thanks for the write-up! P.s. shouldn't 'new Marko_Crop_Top_Center;' be 'new Unkown_Crop_Top_Center;' ?