image resolution (dpi) is completely wrong in Fm 2017

Let's try to break that down. I have created an image with 610 × 457 px at 300 dpi and went through it:

I want to import a jpg file with dimensions of 610 x 457 pixels and 300 dpi.

First: Given, that 1 inch is 25.4 mm, the image dimensions of this test image are 52 × 39 mm:

Length: (610 px × 1 inch) / 300 dpi = 52 mm*

Height: (457 px × 1 inch) / 300 dpi = 39 mm*

* all image dimensions given here are rounded, even if FrameMaker shows the exact number with three decimal places.

Import into a table cell

First I tried to import into a table cell. When I insert this jpg image, the DPI value is Unknown. If I do this via Insert | Image, the scaling in the object properties is 1.97 %. If I do this via File | Import | File, the scaling in the object properties is 4.27 %. Any dpi values during the import are ignored.

I can confirm that. Looks to me like importing an image into a table cell follows its own "rules". Needs further investigation. I will check this with the developers.

Import into an existing anchored frame

When I create an anchored frame first and import via Insert | Image, then the scaling is 72 dpi, no matter, if the image will fit into this frame. If I import via File | Import | File, then the set DPI value is kept correctly.

Yes, if I import the test image via Insert > Image into an anchored frame, it is imported at 72 dpi. Dimension is 215 × 161 mm. Scaling is given as 100%.

Length: (610 px × 1 inch) / 72 dpi = 215 mm

Height: (457 px × 1 inch) / 72 dpi = 161 mm

Yes, if I import the test image via File > Import > File into an anchored Frame and select 300 dpi in the "Import Graphic Scaling" dialog, it is correctly imported at 300 dpi and dimension is correct at 52 × 39 mm. Scaling is given as 24%.

Import into the text flow

When I import the jpg file into the regular text flow, then the results are almost the same. When I import via Insert | Image, then the DPI in the object properties is Unknown and the scaling is 72 dpi. If I import via File | Import | File, then the set DPI value is kept correctly.

Same as importing into an existing anchored frame.

So, with File > Import > File into the text flow or into an anchored frame and setting dpi during import to 300 dpi, FrameMaker imports the image correct at 300 dpi with the correct dimension of 52 × 39 mm. The scaling is given as 24%, which might be a little bit confusing at first. However, the scaling that FrameMaker gives in the object properties is the scaling compared to the image size at 72 dpi.

For the Insert > Image route, FrameMaker imports the image always at 72% (= 100%). When importing an image with this route into an anchored frame, FrameMaker does not scale down the image if it is bigger than the anchored Frame. When importing an image with this route into the text flow, FrameMaker checks if the image is bigger than the frame (at the default import size of 72 dpi). If so, FrameMaker scales down the image until it fits into the new anchored Frame (maximum width = text flow/column width minus anchored frame padding).

Again, importing into table cells is a different thing. I will check this with development. Looks like a bug to me.