Converting Images via the Internal PDF Converter
An internal converter is now always used (in build 18.104.22.168 and later) to convert GIF, JPG and PNG image files to PDF or TIF. This is done by loading the image, into a blank PDF page, and then using the internal converter to create a TIF from it.
This method of conversion has the following advantages:
•The Document Converter print driver is not required. Note, however, that you may still require this print driver for other types of document, so the Document Converter still checks for it. To suppress the checks that this driver is present, set the environment variable NO_CV_PRINT to a non-empty value, and avoid conversions which require the driver.
•The 'speckle' round text characters, especially on JPG images, can be reduced using QPDF_OPTIONS, and other customization of the conversion is also possible using these options.
•Output TIF files are often dramatically smaller and therefore can be transmitted more quickly.
Note that you should not use the SCIMG keyword in QPDF_OPTIONS for small image file such as logo images, which would otherwise be scaled up to full page size. Use SCIMG only when the image is a page-width file which will be scaled accordingly to fit a fax page format. With SCIMG, landscape mode images (wider than their height) are rotated anticlockwise.