On 3.1.10
I have an extension to Image to render images in greyscale.
First image in loop gets rendered to "_resampled" folder but no others, and the one that did get saved doesn't make it to the page.
Any ideas?

Extension looks like this

class Greyscale extends DataExtension {
    public function GreyscaleImage($RGB = '76 147 29') {
        return $this->owner->getFormattedImage('GreyscaleImage', $RGB);
    }

    public function generateGreyscaleImage(GD $gd, $RGB) {
        $Vars = explode(' ', $RGB);
        return $gd->greyscale($Vars[0], $Vars[1], $Vars[2]);
    }
}

Template - each Panel has an image property called Image.

<% loop Panels.Limit(3, 0) %>
            <div class="col-md-3 col-sm-6 hidden-xs nav_grid_top">
                <img src="$Image.GreyscaleImage.CroppedImage(475, 550).URL" alt="$Image.Title" class="nav_grid_img"/>
                <div class="nav_grid_content">
                    <h3>$Title</h3>
                    <hr/>
                    <h4>$SubTitle</h4>
                    <p>$Text</p>
                    <a href="$Link.Link">$ButtonText</a>
                </div>
            </div>
        <% end_loop %>

Thanks.