Avoid image compression issues

  • Updated

Most images you place into BookWright or BookSmart won't encounter any compression-related issues and you won't need to worry about any of this. However, if our customer support team has sent you to this article, it's likely you need to make some changes for the best possible results. 

First, let's look at some important terms and tools.

Image dimensions

When we talk about image dimensions or image size in this context, we mean the measurements of the image in points, pixels, inches, or centimeters, not the file size in megabytes (MB).

With BookWright, you can import the photo into BookWright then double-click its thumbnail in the View>Photos section to see the dimensions, as outlined in red below. You can see this image is 16.1 x 12.1 inches. Metric and pixel dimensions are also provided.  


You can also view image dimensions in programs like Photoshop, Preview, Paint, and other image editing programs. You may also find the dimensions via Get Info (Mac) or  or Properties (Windows).

Container size

The container size means the size of the container you place that image into. In other words, how large the image will appear, on the page, if it completely fills the container.

Here's a photo container in one of BookWright's page layouts. Click the container to view its size as outlined in red here: 



Other units

If you'd rather see the container size in another unit (centimeters or points) instead of inches, be sure you have rulers visible (View>Rulers) then double click the ruler to change the units. 



Small photo, large container

If you place an image into a container that's larger than the image size you'll trigger the low resolution warning.

For example, if I place my 16.1 x 12.1 inch image into a container that measures 19.25 x 8.25 inches, the image gets "stretched" to fit that container. That triggers the Low image resolution warning (upper right corner) and the image won't look as good in print, at least not at that size. 


Large image, small container

If you place a large image into a smaller container then BookWright must reduce the size of the image. For example, if you place a 16.1 x 12.1 inch into the container below (8.81 x 5.54 inches), BookWright will scale down the image to better fit the container.



So what's the problem?

Normally, placing a large image into a smaller container isn't a problem at all. BookWright can scale down high-quality images without any issues.

However, if the image is significantly larger than the container and the image is already grainy, pixelated,  jagged or oversharpened, the image may look worse once scaled down. 

How do you know if your image is grainy, pixelated,  jagged or oversharpened to begin with? Give it the 200% test. In an image editing program that lets you zoom to a numerical value, zoom in to 200%. (BookWright doesn't let you zoom this way, so you need to zoom in using another program). 

If you see any grain, jaggedness, moiré, noise, or other issues at 200% zoom, those  will appear in your printed image and the scaling down will make those problems look even worse in print.

If your image has any of these issues to start and you use the Enhance Image feature (which will further sharpen and brighten the image) it'll make things look worse. Grainy images will look grainier and jagged images will look more jagged.

Here's the Enhance Image feature.


How to get better results

Use the 200% test

First, as above, give your images the 200% zoom test. You can even zoom to 300% for a closer look. This will reveal any issues in the original images.

If things look problematic at 200-300% you should expect to see the same issues in the printed book. You may wish to use a different image altogether. Otherwise, just be aware that the issues you're seeing will appear in the printed book.

Turn off enhance image

Second, if you notice any grain, jaggedness oversharpening or pixelation when zoomed in, don't use enhance imageUnselect that option for that image.

Scale down large images

Third, using the steps in the Image Dimensions and Container size sections above, compare the size of your original image to the size of the image container. If your image is significantly larger than the container size (more than roughly 30% larger) and you've noticed any issues at 200% zoom, do the following:

  1. Duplicate the original image (to preserve the original for other uses). 
  2. Note the size of the image container in BookWright (as seen by clicking the container).
  3. In a photo editing program (such as Adobe Photoshop, Preview or whatever you have available) reduce the image dimensions so they're closer to the container size found in step 2.
      1. If the image dimensions are a little bit larger, that's fine. You might not be able to get an exact match. But try to get them as close as possible, within 15% of the container size.
  4. Swap that resized image into BookWright. 
  5. Make sure Enhance Image is turned off. 
  6. Review everything carefully.
  7. Upload and order that new version.

These steps will help minimize, but may not entirely eliminate, any jaggedness, grain, moiré, artifacting, or oversharpening issues in the original. 

Ultimately, if there are issues in the original image they will appear in the printed book, too. These steps can help minimize these issues. We always recommend you order and review a single proof copy of any new version, especially before ordering in bulk or making the book available for sale to the public.

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