I love my kindle (3) — it has brought me back to reading fiction, reading more non-fiction than ever, being more productive in my work-related reading, and just appreciating quality texts. But to my surprise, I love its non-reading features almost as much. The ‘experimental’ browser is handy if you’re selective about which web pages you bookmark, and the couple of games might be handy while nervously passing time in a waiting room. Yesterday my daughter didn’t want to travel home in the car — offered her some music courtesy of the kindle and soon she was falling asleep to Rod Stewart. Best of all, when it’s asleep itself, it is my digital picture frame, showing some of my favourite family pictures without using any of its amazing battery life.
Here I’ll jot down my steps for quickly achieving top quality images tuned for the kindle while minimising strain on CPU and diskspace. (These notes are for B&W 6-inch (600 x 800) kindle screens, not DX nor Fire.)
First create a brand new folder to work in and put in it brand new copies of your favourite pictures. (In picassa the easiest way is to browse for a picture you like, then locate it on disk (<Ctrl>+<Rtn>) then copy & paste to your new folder.) For me that means high resolution colour images from my camera, which happen to be jpg. In picassa, define a ‘Custom format’ of 600 x 800 called “Kindle”. Point picassa at your new folder and carry out the following for each picture.
- View and Edit (shortcut = <Rtn>)
- Basic Fixes > Crop
- Select Kindle, drag the rectangle around to suit
- Quickest is to choose one of the proposed crops, possible using ‘rotate’, then resize/move to suit
- Keep your produced images either all portrait or all landscape
- This is for cute pics of my daughter; might not be appropriate for your selection
Your picture is now in the right ratio with pretty decent cropping and contrast, but it’s a fair bit bigger than it needs to be. If you don’t care about diskspace or how quickly pictures are rendered then you can skip the next section.
Now we open up gimp and optimise the file format.
- File > Open
- Image > Mode > Grayscale
- Image > Scale Image
- Set resolution to 166
- Un-chain Width & Height so they can have unlinked values
- Set them to be 600 and 800
- You probably want ‘Cubic’ interpolation
- File > Save As
- Change suffix to “png”
- Untick everything except ‘Save resolution’
Your picture is now in a smaller (png) file. (Might be worth comparing your ‘before’ and ‘after’ sizes, but with my pictures they became much smaller — less than 250 kB.)
If your kindle doesn’t have a ‘pictures’ folder, create one at its root and then create a subfolder for your pictures (eg /kindle/too_cute). Put your .png pictures into the sub-folder, go to ‘Home’ in the kindle, refresh via <Alt>+<z>, then you should be able to open the folder of pictures in the same way you would access a book.
To have these pictures be your new screensaver images, you need to follow the steps at Kindle Screensaver Hack, putting your pictures in the /linkss/screensavers folder.
There are a couple of improvements that could be made to this recipe. It’s ok for twenty pictures, but if you were doing two hundred, you would want to use gimp’s scripting approach. The generated picture files have meta-data relating to the edits, but I’d much rather copy the meta-data (eg creation date) from the original files. One day I’ll write a perl script to copy selected meta-data from each jpg to the corresponding png.