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Image interpolation

PDF manual "png2pdf.pdf" available

Image interpolation can be used to obtain smoother color transition when low-resolution bitmap images are rendered to large screen areas or print areas.
The examples are from screenshots of the SourceForge logo converted to PDF and shown expanded to fit the page width.
The first conversion was done without setting an Interpolate entry in the image dictionary, the second one uses the Interpolate entry.

Figure 1: Image without interpolation

Figure 2: Interpolated image

As seen in the images above interpolated images may look better on screen than images without interpolation.
When using png2pdf's interpolation option keep in mind that the interpolation algorithm used to show the image depends on both the viewer software used and the output device.