Trouble with ImageMagick, because of disabled Escapeshellcmd-function?

I’m having trouble getting ImageMagick to work in a recent install of Omeka 2.5. I have entered the correct path in the settings, but when hitting the test-button I get the following error:

Omeka_File_Derivative_Exception: Failed to execute command: ‘/usr/local/bin/convert’ -version. in /home/breednetw1/domains/
Stack trace:
#0 /home/breednetw1/domains/ Omeka_File_Derivative_Strategy_ExternalImageMagick::executeCommand(’’/usr/local/bin…’, NULL, NULL, NULL)
#1 /home/breednetw1/domains/ Omeka_File_Derivative_Strategy_ExternalImageMagick::isValidImageMagickPath(’/usr/local/bin/’)
#2 /home/breednetw1/domains/ SettingsController->checkImagemagickAction()
#3 /home/breednetw1/domains/ Zend_Controller_Action->dispatch(‘checkImagemagic…’)
#4 /home/breednetw1/domains/ Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http))
#5 /home/breednetw1/domains/ Zend_Controller_Front->dispatch()
#6 /home/breednetw1/domains/ Zend_Application_Bootstrap_Bootstrap->run()
#7 /home/breednetw1/domains/ Zend_Application->run()
#8 /home/breednetw1/domains/ Omeka_Application->run()
#9 {main}

I have contacted the hosting-supplier for help and have done some googling myself. Somewhere I read that the problem may be caused by the PHP-function escapeshellarg being in some “disabled functions list” in the server-settings. I’ve asked the hosting-supplier to check whether the function is indeed disabled and sent them the ExternalImageMagick.php-file. They responded that the function escapeshellarg is not disabled, but the function escapeshellcmd is! They did this for security-reasons and refuse to enable the escapeshellcmd-function.

Is the fact that escapeshellcmd is disabled indeed causing my problems with ImageMagick?
Is there a way to solve this, without enabling escapeshellcmd?

(P.S. PHP 7.0 is installed on the server)

That seems pretty likely. The alternative is to use one of the other options for creating derivative images. That’d just mean changing the setting described there in your application/config/config.ini file. One of those (IMagick or GD) is more likely to work. And, if not, your hosting provider is more likely to install one of those to make it work.