#5 Code question. Need DPI of image

[Artem]

Hello!
I was begginer programmer. In your project I needs width and heigh image in mm. For it's need DPI of image. DPI was stored in EXIF by address 0x011a in Rational type. In the code exists method ReadRationalTag(...), but with him DPI was wrong.
How can I get access to DPI of image?

[David Kleiner]

Some formats (like bmp) can store a DPI value but its value is typically not set.
In JPEG I assume that almost no camera sets the DPI of an image because it's simply not known as it depends on the distance of the subject.

David