grunnvms

Yes, I know. However, if there are many images in a multi-page document, it will dramatically increase the size of the document. So I prefer preparing the images as they should be in the document.

Thanks Petar, I get you points, but I do have some remarks. Cameras most certainly do put a dpi setting in the image headers. Often it is 72 dpi, some cameras use 300 dpi. The reason will be that there is at least some setting that will produce a printable image. Most people will not use a program like AP, or PS to manipulate their images. I always use the raw image from my camera, and leave that untouched. When I have worked on the image, I will save it as PSD (with PS or) the native file format of AP. I will make.jpg copies of that image for the purpose I need them for. If I use it in a document, I will set the size in cm, and the dpi setting, and then recalculate the image. For a web image, I will just set the pixel size and recalculate. After all, the dpi setting has no effect for web images.

Resizing is a bit of an ambiguous expression. An image has a size in pixels, but pixels have no dimension in inch or cm. Changing the number of pixels however, is certainly seen as resizing. If you want to print an image, then the actual size of the print will be determined by the size of the image in pixels, and the dpi setting. If you have an image of 600 x 600 pixels, and a setting of 300 dpi, then the resulting image on paper will be 2 x 2 inch. Change the dpi setting to 150 dpi, and the print will be 4 x 4 inch. So changing the dpi setting of an image is also seen as resizing. Even though the pixels are not even touched, the size of the resulting image on paper will be changed. To sum it up, resizing can mean changing the number of pixels, changing the dpi setting, or both at the same time. The dpi setting is stored in the TIFF headers, or in the EXIF headers, but not in both. It is no more then comment really, it doesn't do anything with the pixels. The topic starter is rightfully complaining that changing the dpi setting (= rewriting the dpi setting in the headers) doesn't work in AP. That is indeed a very silly and annoying bug that should have been resolved long ago.

I just installed the latest version of Affinity (1.6.5.123) , and the problem is still there. For people working with Affinity, this is not a minor problem, it is a very annoying problem. Technically it will be a minor problem to solve. When you are producing documents, and you have to insert images in those documents, then you need to prepare those images for insertion. That means that you know the size of the images in cm (or inch), and you know the dpi setting for all images in the document. The dpi setting is necessary to guarantee the print quality of the final product. So you take an image, fix all the photographic problems, and then as the last phase of this process, you give it a size in cm (or inch), and a dpi setting, and resample it. The resulting image file has a certain size in pixels, and should have the proper dpi setting entered in the headers. When you insert the image in the word processing software (or whatever software you are using for the primary document), it will calculate the desired image size in cm based on the size of the image in pixels, and the dpi setting. If the dpi setting is wrong, the image size (in cm) will be calculated wrongly. Affinity can find the dpi setting of an image, now how difficult can it be to rewrite the dpi setting with the required value????? To be honest, there is one annoying problem. The dpi setting can be in the TIFF headers, or in the EXIF headers, but not in both! It seems that these days the EXIF headers are the proffered place for the dpi setting. When I read the release notes of the new version, I see that all kind of things have been fixed. I doubt very much if I will ever use many of those things. I'm sure it must be very challenging to fix all those complicated problems. But please gentlemen, can you please fix this minor problem as well? It is a bit silly that we have to use other programs as a work around to fix this annoying bug.

Yes, I know. One of them in no longer maintained, so I will try the other.

IrfanView opens the image, and rewrites the image. That is not what I want. LibreOffice reads the dpi setting of the image, and calculates the size of the image from there. So the effective dpi settings is the same as the dpi setting in the header. If you change the size of the image, it will be resampled. The dpi settings remains the same. The graphics part of LibreOffice needs some overhaul, it's not working like I (and others) would like to see.

Indeed, LibreOffice has a good PDF export. Don't know if it supports CMYK. I suppose Affinity supports CMYK? Have just been using it for two days or so :-).

I'm trying to find a workable Exif editor, but a program like IrfanView also touches the image. I'm using LibreOffice, and LibreOffice resamples the file. It doesn't use effective PPI. However I don't think there is a limit to the dpi setting of an image, LibreOffice just looks at the size in inch/cm.

The way that I want to prepare images for insertion in a document is very simple. I open the original image, open the 'Resize Document' panel, enter the desired dimensions , choose the desired dpi setting, and click resample. Very simple. I can then just insert the image in the document, without touching it. That is the recommended way for inserting images in documents with a word processor. And using the 'Resize Document' panel this way is exactly what is is intended for.

That's great, but I'm not using QXPress or InDesign. I'm using a word processor, and I don't want a word processor to touch my images. The images should be imported 'as is', for that I need the proper dpi settings in the headers. That's why these settings are there.

As others have stated, the dpi setting is noting else than a kind of comment in the headers. It tells an application how to calculate the size of an image for use in a document as well as a print. The dpi settings can be found in the TIFF headers, or the EXIF headers, but they should not appear in both !! For printing 300dpi is good value in many cases, Unfortunately many camera's set the value to 72 dpi in their EXIF data. That is a useless ridiculous value. Browsers etc. only look at the pixel dimensions, not at dpi. When you prepare images for use in documents (books etc.), then you will use 'Resize Document' to set the appropriate size (inch, or cm, or mm) and dpi setting to calculate the pixel size of the image.It is vitally important that this dpi setting is preserved in the headers, otherwise you can't properly insert the image in the document without extra work.It seems Affinity is not setting the proper dpi value at the moment. Should there be a header editor in Affinity? Yes of course, even Photoshop Elements has one. You may want to add copyright information, a description of the image, and so on. For the moment I have to find a proper EXIF header tool, that doesn't touch the image itself. It seems Exiftool is embedded in Affinity, but in read-only mode. Using it in stand-alone mode means using a command line tool, not really what I'm looking for. So please developers, get the header editor incorporated in Affinity as soon as possible, and before that, make sure the dpi setting is preserved in the headers !!