嘗試:
$transfer = new Zend_File_Transfer_Adapter_Http();
// $transfer->addValidator(new Zend_Validate_File_IsImage());
$transfer->addValidator(new Zend_Validate_Callback(function($filepath, $file) use($transfer){
$mimes = array('image/bmp', 'image/c', 'image/cgm', 'image/fif', 'image/gif', 'image/jpeg', 'image/jpm', 'image/jpx', 'image/jp2', 'image/naplps', 'image/pjpeg', 'image/png', 'image/svg', 'image/svg+xml', 'image/tiff', 'image/vnd.adobe.photoshop', 'image/vnd.djvu', 'image/vnd.fpx', 'image/vnd.net-fpx', 'image/x-cmu-raster', 'image/x-cmx', 'image/x-coreldraw', 'image/x-cpi', 'image/x-emf', 'image/x-ico', 'image/x-icon', 'image/x-jg', 'image/x-ms-bmp', 'image/x-niff', 'image/x-pict', 'image/x-pcx', 'image/x-portable-anymap', 'image/x-portable-bitmap', 'image/x-portable-greymap', 'image/x-portable-pixmap', 'image/x-quicktime', 'image/x-rgb', 'image/x-tiff', 'image/x-unknown', 'image/x-windows-bmp', 'image/x-xpmi');
if(!in_array($file['type'], $mimes)) {
$transfer->addError(sprintf("O arquivo não é uma imagem: '%s' detectado", $file['type']));
return false;
}
return true;
}));