Under what circumstances does it make sense to resample images? What are the correct settings? (SIZE)
We recommend resampling only if the output size is known to Pixometry. This is the case in the following situations:
You are processing PDF. Pixometry knows the size that images have on the PDF page/document.
You are using our Indesign Jobclient. Pixometry knows the size that images have in the Indesign document.
You have one of the fixed size options checked in SIZE settings, like “width in pixels” or similar.
If none of the above is true, we recommend to uncheck the resample checkbox and not resample images. If you do check the resample checkbox in that situation, Pixometry will resample based on the DPI value of the original image. This may lead to “random” resampling results. For example, you may have two images with 8 million pixels. One image may have a DPI value of 72, the other 300. The DPI value in a digital image is only a metadata field in the header of the image and says nothing about the image quality. It is merely an output intent that can still be changed at will. The image information is in the 8 million pixels, so both images have the same amount of information. If you do DPI based resampling with a target of 300 DPI, that will lead to one image with 8 million pixels (the one that had already 300 DPI) and the other image will be resampled from 72 to 300 DPI, leading to an image of more than 32 million pixels.
It is also possible to just set the DPI value without resampling the image. That is the preferred option in this case.