PDFs are designed to use full colour with transparency. We generally use ARGB to provide the best quality display of PDF content and we are always trying to improve our quality of output. So it was something of a culture shock to have several inquiries about making the output WORSE. They wanted the PDF displayed or printed in Grayscale or black and white…
Taking a PDF an making the output grayscale or black and white does result in some image deterioration which varies from file to file. On a page of black and white text it is negligible whereas it can have a big effect on images. Here is an example. The original…
and in black and white…
As you can see in this example, grayscale works well whereas black and white does impact image appearance.
The advantages of having a PDF in grayscale or black and white are that it allows for a smaller image size and allows it use in faxes (which do not seem to be as extinct as I had believed). It also means that people who do lots of printing can use the cheaper print modes.
There are several ways to convert a PDF to grayscale or black and white. If you are using JPedal and want to use the feature we have added, there is a new tutorial here.
This post is part of our “Understanding the PDF File Format” series. In each article, we discuss a PDF feature, bug, gotcha or tip. If you wish to learn more about PDF, we have 13 years worth of PDF knowledge and tips, so click here to visit our series index!
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