[Impress] How can you adjust the size of area?

At this moment I have a text box. How can I adjust the size of this text box? Let say I want it 600 pixels in width and 200 pixels in height.

As far as I can tell, pixels are not an option for dimensions. From the Tools → Options dialog, select LibreOffice Impress → General and you’ll find “Unit of Measurement”. These seem to be the only options.

You cannot work directly in pixels because currently they are not supported. There’s a filed bug for enhancement here:
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What you can do is set the ratio conversion when exporting a slide (or many) to a graphic picture (jpg, png, …). You can specify the total width (or height) so you can have a direct reference between mm and pixels. Unfortunately this is the only way to do it I am aware (and this is how I do it to create my screen overlays).

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