You want your eBook size to be as small as possible because Amazon charges you a 15 cents per megabyte download fee. You want your web images to be as small as possible so your website loads faster. In this post, you'll learn how to optimally resize image files to strike a balance between file size and quality. Here are the steps:
1. Change the dimensions
2. Save for web
3. Remove extraneous metadata
4. Now squoosh it
But First, JPG vs PNG
First, a little about file types. The main difference between JPG and PNG is their compression method. JPGs are meant for photographs. They are smaller in file size because their compression algorithm is "lossy" and removes some of the image's information. Use JPG for all your photos and web images unless they need transparency or have text in them. When you save an image as JPG it flattens it, so the nuances of transparency (opacity) are removed. Text in JPG images often become pixelated. So go with the larger PNG format or, better yet, use captions instead of embedded text.
Use PNG for small images like line drawings, icons, charts, and text-based graphics such as screenshots of fancy chapter titles, headings, and flourishes that replace plain-text chapter titles in your ebook file. (You can't count on e-readers and other devices to translate non-standard fonts correctly.) When you save an image as a PNG you don't lose any data during compression because it's "lossless," so the detail is preserved.
The difference is significant. A PNG image with a file size of 402 KB saved as a JPG would be only 35.7 KB, but you'd lose a lot of detail.
Okay, now on to the four steps to resize image files.
1. Change the Dimensions
First, make a copy of the image. Don't work with the original image!
Change the height and width of your image to 1600 pixels on the shortest side if you want it to fill the screen on a tablet, or 800 pixels if you're targeting e-reading devices and smartphones. If your image is smaller than that, it won't fill the screen.
If you don't need to crop your image, you can resize it using Google's free Squoosh App, described in Step 4.
2. Save for Web
Once you've changed the dimensions of your image, compress it using Photoshop or GIMP by Saving or Exporting for Web. Use a quality setting of 40.
3. Remove Extraneous Metadata
This is the first step to making them smaller by getting rid of extraneous data.
4. Now Squoosh It
The final step to making your image as small as possible is to squoosh it using Google's free Squoosh app. Open Squoosh in your browser, then drag-and-drop the image onto the Squoosh icon. Use sliders to compress the file size until you see degradation, then slide it back up.
I tried Squoosh with this print-quality photo of a dog.
And... the Resulting File Sizes
From top to bottom, here are the file sizes. Do you think the image quality suffers? I think not.
- 518 KB dog-original-print-quality.jpg
- 66 KB dog-save-for-web-40.jpg
- 33 KB dog-squooshed-50percent.jpg
Now you have beautiful, small-sized images to place in your eBook and on your website.
TIP! If you think your eBook images may be too small for a smartphone, upload large-sized images to your website and create a link to them in your eBook. This can be especially useful for readers if you included graphs and charts with a lot of detail.
ANOTHER TIP: Create a separate PDF eBook with the images your readers can download. Use it as a lead magnet by requiring readers to enter their email address. Make it friendly to readers who have not purchased your book by adding just enough information to compel them to buy.
Was This Helpful?
I hope this post helps you create high-quality, small file-size images for your eBook and your website. It will make a difference to your royalty deposits, your eBook readers, and your website visitors.
Are there any tips or tools that you use to resize image files? Questions? Please let me know in the comments section below. Thanks!