Inserting image in Writer without scaling

I want to insert some pictures in a Writer document. I have prepared the images in Photoshop Elements, and with a 300PPI resolution they have the correct size in cm. Since I want it to be a nice printable document, this is the resolution I want to use.

When I insert the image, Writer will assume a 96dpi resolution, and a picture size as big as possible on my page. I then can adjust the size in cm, to get the picture size I need.

With Compress Graphic I can then change the DPI setting, but I notice that Writer will do all kind of recalculations to get to the result that I want. Writer first recalculates the original image to 96DPI and the cm size I want, and then recalculates it again to 300DPI. That will not add to the quality of the picture.

Writer should have the option to calculate the size of the image in cm, just by setting the desired DPI setting, and without recalculating the image. So if the image width is 1500 pixels, and I set the resolution to 300DPI, the width on paper will be 5 inch or 12.7cm. Simple and straightforward, no need to touch the actual pixels.

After all, programs like Photoshop are more suitable for these kind of calculations, and if you have such a program you will prepare your images there. Writer then shouldn’t touch the pixels any more.

I have found the problem. LibreOffice doesn’t always understand or find the dpi information in the headers of an image, and will assume the dpi setting of the screen of my laptop. There is a bug report on this matter (52598) dating back from 2012. It should be quite easy to fix, if a developer would take the time to look at it. It is a major problem, since it prevents you from inserting images with the proper dpi setting.

I use LO; when I insert images, LO adjust it to the text width. I tested with an automatic legend and without it. It works the same. The procedure is: activate the menu, select Insert – Image – select your image – enter.

That is how you insert an image, I know how it works. The problem is the size of the image. The size is stated in pixels, and the dpi setting in the header of the image should tell Writer what the resulting size in inch in the picture should be. Pixels divided by dpi = height or width of the picture in inch. However Writer does not read the dpi settings, and uses the dpi settings of the screen resulting in the wrong size in the document.