Sorry, I cannot reproduce this. I have created a sample book with code, images and CSS as you describe. It displays the image centred correctly on both my Touch and Aura H2O. If it isn't on you Touch something else is happening. There are two likely possibilities I can think of.
Are you sure there are no errors in the book? And especially the styles? If there is, the Kobo firmware will completely ignore the stylesheet. Hence, the image and text would be left justified.
In any case, unless calibre is generating code that is invalid, this is not a calibre problem. If you are having problems with the books on the device, I suggest posting in the Kobo forum at MobileRead.
Sorry, I cannot reproduce this. I have created a sample book with code, images and CSS as you describe. It displays the image centred correctly on both my Touch and Aura H2O. If it isn't on you Touch something else is happening. There are two likely possibilities I can think of.
Are you sure there are no errors in the book? And especially the styles? If there is, the Kobo firmware will completely ignore the stylesheet. Hence, the image and text would be left justified.
In any case, unless calibre is generating code that is invalid, this is not a calibre problem. If you are having problems with the books on the device, I suggest posting in the Kobo forum at MobileRead.