PDF to image quality

The PDF file format was designed as much as possible to be Vector graphics. The problem with bitmaps and pixels is that pixels can only be on or off. While you can use some clever tricks such as anti-aliasing and hinting to smooth lines, you can’t draw fractions of a pixel. If a line is…

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PDF text co-ordinates

There are several ways to define PDF text co-ordinates with PDF. When you see the text onscreen, you can see the actual character. The outline of this is known as the ‘visible text box’ – if you draw it onscreen it would just touch the edges of the character. When a font is designed, most…

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What is PDF pagesize?

Page size can cause some confusion with PDFs because there are several possible values. All PDF files have a MediaBox which defines the size of the PDF in units. Values 0,0,595,842 (listed in the file as an Array [0 0 595 842]) are the normal values for an A4 portrait page, although they can also…

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JButton backgrounds

We use a lot of JButtons in our Java PDF viewer and thought that the following observations might be of help to other Java developers. When you create a JButton it can be transparent (no background) and you can see through them or have a background color. This is done using the method setOpaque(boolean flag)…

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