Object Export Options allow you to control the position, size, and other aspects of page items for reflowable EPUB. Issues that can occur with live text, non-rectangular objects, polygons, strokes and arrowheads, drop shadow effects, and type on a path are all demonstrated and fixed with the use of object export options.
- [Instructor] In previous movies we looked at the process of exporting to EPUB and how you can get better results by structuring content with the Articles panel and anchoring items, like photos, so they appear in the right places. Next, let's take a look at how to control the position, size, and other aspects of page items with Object Export Options. I borrowed this exercise file from Anne-Marie Concepcion's course InDesign CC: EPUB Fundamentals. And while it's not the most attractive design you ever saw, it does a fine job of illustrating the problems that can occur when you export certain layout objects to EPUB and how to fix those problems with Object Export Options.
So first we have an ellipse filled with just a color, lower down we have another ellipse with a color and some text in it, and we have to instances of text on a path. One with a stroke applied, and one with no stroke. Down at the bottom we have a line with an arrowhead applied, via the Stroke panel, and we have two polygons in the shape of stars. One with a photo in it, and one that's empty. All of these objects have been added to an article called shapes to control their position in the EPUB.
So let's just export as-is to the Desktop. I'll just call this Objects. And if I were to export the layout to fixed layout EPUB I would see all the elements as they are, but they would be rasterized, turned into a picture, with the exception of the text in the yellow ellipse, which would remain live text. The other text on a path would have to be rasterized, since no kind of EPUB supports text on a path. But let's export to Reflowable EPUB by choosing it here, click Save, make sure Content Order is Same as Articles Panel, and click OK.
And right away InDesign warns me that this EPUB is not gonna look like my layout file. So the non-rectangular objects are gonna change and the text on a path is just gonna be ignored. That doesn't sound very good, but I'll click OK, and boy, did things change. Our blue ellipse was converted to a blue rectangle, the text on a path was ignored, just like we were warned it would be, the stroke path was converted to a rectangle the size of the width and height of that path, and even though we can't see it right here, the same thing happened with the path with no stroke.
That's why there's this empty space here. Our elliptical text frame was converted to a rectangle, and our line lost its arrowhead, and also notice that it's not a line. It too was converted to a rectangle. And even though it's gone, the arrowhead did have an effect. The height of this rectangle matches the height of the arrowhead. Also notice that this rectangle is filled with black. If I switch back to InDesign and select the arrow I can see that it has a black fill. Of course, I couldn't see that in my layout, because a straight line has no interior space where it can display a fill color.
I'll go back to iBooks. And we come to our star with the photo in it, that actually looks good, even has its drop shadow, but the green star didn't fair so well. It got converted to, you guessed it, a rectangle, and it also lost its drop shadow. So let's go back to InDesign and use Object Export Options to fix these problems and create a reflowable EPUB that approximates the look of our layout file. I'm just gonna select everything on the page except the star with the photo in it, since that came out OK, and choose Object, Object Export Options.
And this dialog box has three tabs. On the left you can add Alt Text to images, which is a key task for EPUB and accessible PDF. You can also tag content for accessible PDF in the second tab. And if this is something you wanna learn more about definitely check out the course Creating Accessible PDFs by Chad Chelius where Chad explains all these options and demonstrates how they affect PDF accessibility. But for our purposes we're interested in the third tab, EPUB and HTML.
In here we can choose one of the options in this menu, Preserve Appearance From Layout. We have four choices here that can affect how images, InDesign objects, and groups are rendered in EPUB. The first is Default. And when I select that notice how some of the other controls become greyed out. Default means that the settings you choose in the EPUB Export dialog box will determine how the image or object is rendered. So I would choose things like a file format and resolution at export time, not here.
But I can still choose things like layout, spacing, and sizing, and so forth. The second choice in the menu is Use Existing Image for Graphic Objects. Note that the same controls are greyed out. With this choice if the object contains an image in JPEG, PNG, or GIF format then the container will be styled using CSS, and the image itself will be passed through to the EPUB untouched. So whenever possible the existing image will just be used without altering it, but the container's appearance might change.
For example, if you applied a drop shadow, that would disappear in the EPUB. The next choice is Rasterize Container. This will rasterize the whole object, including the text, to preserve its entire appearance in the output, including things like effects and drop shadows. And you now have the options here to choose a file Format, a Resolution, Quality, and so on. This choice of Rasterize Container is the same as choosing Preserve Appearance From Layout in the reflowable EPUB Export dialog box.
The last choice here is Rasterize Content. Here the graphic content of the object is rasterized, but not the whole object. So the formatting of the container is controlled by CSS, like it is with the choice Use Existing Image, and so the container may appear different in the output than it did in InDesign. The difference here is now I have controls to affect the Rasterize Content instead of passing the image through untouched, like I would with the first choice. But let's say our goal here is to get as close as we can to the appearance of our layout.
Then the only choice is Rasterize Container. This'll basically make a picture out of all the items that cannot be represented with HTML and CSS in the EPUB. So all these items will be converted to JPEGs, and we'll set them to 150 ppi, and leave the rest of the settings as-is. So I'll click Done, and let's export to reflowable EPUB. We'll export to the Desktop, overwrite any existing file, and just click OK, and there we go, the look of the layout was preserved thanks to Object Export Options and also the use of the Articles panel for the content order.
Note that using Rasterize Container made a picture out of everything, including the text in this ellipse. So you might wanna copy that text and enter it as alt text for that same object in the dialog box that we used. I'll jump back to InDesign just to show that. I'll select all the text in the ellipse, copy it, select the frame, and choose Object Export Options, which you can also do just by right-clicking on a selected object. I'll go to the Alt tag options, I'll choose Custom, and paste in the text that I copied, and click Done.
Now that text will make it into the EPUB and can be read by screen reading software. So in this movie we saw how to use Object Export Options to control the appearance of objects in reflowable EPUB. It's a key feature for retaining the look of your layout when it contains formatting that can't otherwise be represented in HTML and CSS that make up an EPUB.
- Overview of interactive document types, including PDF and EPUB
- Creating interactive objects
- Setting up hyperlinks, cross-references, and a table of contents
- Working with media
- Publishing documents with Publish Online
- Creating EPUBs
- Following workflows for interactivity: interactive PDF, reflowable EPUB, and fixed-layout EPUB