Usually i am using export to PNG because in further those animations require addition of special effects (glowing,shining,etc.) in Adobe After Effects. So basically i am doing my part of animation first and then other people doing their part in After Effects but every time they need to resize my PNG sequence to proper size. I wish for the situations like mine there were some sequence size adjustment options. For example i need to export my animated icon to PNG sequence with size of 250x250 but how can i do that if the source files sizes are twice bigger and there is no option to set the proper size for the sequence?