How to get cropped image dimensions in a Fluid template in Typo3 v8

Question

Is there a way to get the actual image size (width/height) of a cropped image ("Image manipulation" > [Open Editor]) in a fluid template?

All I can come up with is {image.properties} and width and height. But these are the dimensions of the original resource, not the cropped one. And there is of course an attribute crop which holds all the crop info:

{"default":{"cropArea":{"height":0.6431784107946027,"width":0.608,"x":0.037,"y":0.15592203898050974},"selectedRatio":"NaN","focusArea":null}}

But do I really have to find a way to parse this in fluid (if that's even possible)? Isn't there an official way to calculate the actual dimension of a generated image?

My use case is an image gallery component for which I need to explicitly state the image dimensions.

Answer 1

I have to answer my own question 7 years later :-) sorry for that.

Here is a viewhelper (typo3 v12) which basicly does what I wanted to achieve:

<?php

namespace Vendor\Extensionname\ViewHelpers;

use TYPO3\CMS\Core\Utility\GeneralUtility;
use TYPO3\CMS\Extbase\Utility\DebuggerUtility;
use TYPO3Fluid\Fluid\Core\Rendering\RenderingContextInterface;
use TYPO3Fluid\Fluid\Core\ViewHelper\AbstractViewHelper;
use TYPO3Fluid\Fluid\Core\ViewHelper\Traits\CompileWithRenderStatic;
use TYPO3Fluid\Fluid\Core\ViewHelper\ViewHelperInterface;

/**
 * ViewHelper to calculate croped image dimensions
 *
 * inline example: {yourvendorshortcut:CroppedImageHeight(image: image, width:'1000', variantname: 'desktop')}
 */
class CroppedImageHeightViewHelper extends AbstractViewHelper implements ViewHelperInterface
{
    use CompileWithRenderStatic;

    public function initializeArguments()
    {
        $this->registerArgument('image', 'mixed', 'Image', true);
        $this->registerArgument('width', 'int', 'Image width in fluid template', true);
        $this->registerArgument('variantname', 'string', 'Variant name', true);
    }

    /**
     * @param array $arguments
     * @param \Closure $renderChildrenClosure
     * @param RenderingContextInterface $renderingContext
     */
    public static function renderStatic(
        array $arguments,
        \Closure $renderChildrenClosure,
        RenderingContextInterface $renderingContext
    ) {
        $width = (int) $arguments['width'];
        if ($width === 0) {return '';}
        $image = $arguments['image'];
        $imageProperties = $image->getProperties();
        $variantname = $arguments['variantname'];
        $cropinfo = json_decode($imageProperties['crop'], true);
        if (isset($cropinfo[$variantname])) {
            $originalCropedWidth = $imageProperties['width'] * $cropinfo[$variantname]['cropArea']['width'];
            $originalCropedHeight = $imageProperties['height'] * $cropinfo[$variantname]['cropArea']['height'];
            $aspectRatio = $originalCropedHeight / $originalCropedWidth;
            $height = floor($width * $aspectRatio);
            return $height;
        }
        return '';
    }
}