The color image I'm using for the cover and for one of the recipes.
If I just greyscale it, it will look like this.
The rest of the tutorial for writing books for the Kindle is here.
Kindle images can be tricky. If you're into craft books like I am, you've noticed some images just don't work well on the Kindle. The e-ink technology does have it's limitations and works best with high contrast images.
The pixel display of the Kindle2 is 522 pixels wide by 622 pixels. It can scale but I prefer to create my images within that size.
The 16 color display being grey means that images with light grey tones lose a lot of definition on the screen. So you'll want high contrast grey scale images. You can use jpg, gif or png format. I usually use either jpg or gif.
You'll save your images in the same file as the html for your book so you'll only need the image file name for the image tag since they will be in the same location.
An image tag looks like this <img src="imagename.jpg">
For my examples, I wrote a short collection of recipes.
The color image I'm using for the cover and for one of the recipes.
If I just greyscale it, it will look like this.
Not enough contrast for the Kindle. The light grey tones will be completely washed out when viewing it.
The easiest way I've found to do greyscales and get the contrast where I want it is with Xero's Filters. There is a free Photoshop compatible filter for greyscaling there. The filter has sliders to adjust for contrast and brightness. Brightness makes the light parts lighter, contrast makes the dark parts darker and it has a preview window so you can get an idea what it looks like.
You could also try a halftone filter which will give you a black and white image in half tones.
Using a halftone filter on the same image, this is what I got.
Using Xero's Greyscaler
Different images give you different challenges in getting them high contrast enough to look good in a Kindle book. Take the following examples.
This shortbread has a lot of lighter and medium values. So I need to make it darker without losing the delicate crumb and the detail of the edges. These were the right settings in the filter for that.
This has the opposite problem. The vanilla bean is very dark. The last settings would just turn it into a dark smudge. I need to make the lighter parts lighter so you can still see the sheen of the vanilla caviar.
Here were the settings I used for that.
Experiment. But remember that all the white in your image will actually be grey.
So now for the cover. I create my covers at 1600 pixels wide by 2000 pixels tall because that's the preferred size to upload to the DTP site. Then I resize it to fit the Kindle screen, generally I go 400x500 pixels or 25% of the original. I'll save a color version of that to use for links, then greyscale it the same way I greyscaled the other images to use in the html for my book.
Diagrams. Sometimes you need simple diagrams. Draw them remembering the that you need a lot of contrast so to be the most effective, using only black works best. I've found that I can use dotted lines and half tone fills to simulate shades. For this book, I only needed one diagram. I used a stroke that was 2 pixels wide and anti-aliased to create the diagram.
