SOpt

HTML

<script src="http://jqueryvalidation.org/files/dist/jquery.validate.js"></script>
<script src="http://jqueryvalidation.org/files/dist/additional-methods.js"></script>
<form id="form">
    <input class="form-control" id="ImagemUpload" name="ImagemUpload" type="file" value="" />
    <input type="submit" value="Enviar" />
</form>

JavaScript

$('#form').validate();
$('#ImagemUpload').rules('add', {
    accept: "image/jpeg, image/pjpeg",
    messages: {
        accept: "Formato inválido."
    }
});