How to add a company logo or a marking seregraphy with "Allegro PCB Design"

Seems like v17.2 and later has improved the logo importing capability.  This is what worked for me. Your mileage may vary.....

1) .bmp is the only supported image type in OrCAD, at least in 17.2.  I had to convert a jpg to bmp using a free online converter.  Hopefully you have access to more sophisticated (i.e. uncompressed) file types and image manipulation programs, and your original logo is an uncompressed file type.  I didn't see any issue with jpg compression in the final result of my logo import though, and it is "good enough" for all intents and purposes. I used a monochrome image, I don't know what will happen if you have a multi-color image.

2)  Resize image to the size you want it to be on your board.  I opened it in Paint.  In Paint, go to File->Properties (there is a resize button, but this only resizes in % or pixels).  Select Inches, and you can resize the width and height that you want.  Unfortunately, in paint, the aspect ratio is not locked, so you will have to hand calculate the aspect ratio if you don't want it to skew.  I used https://www.calculator.net/ratio-calculator.html (use at your own risk). I'm sure that there is an easier method to do this, but this was my first cut..... Save the image in your project file location.  BTW MY IMPORTED LOGO DID NOT TURN OUT TO BE THE SAME SIZE AS WHEN I RESIZED IT IN PAINT. NOT SURE WHY, YOU'LL HAVE TO PLAY AROUND A BIT.... In Paint it says 1.39" wide, and placed in my PCB it is 0.42" wide....

3) In Orcad Layout, New->Drawing and select Mechanical (this is creating a .dra file).

4) File->Import->Logo.  In the "Input Logo File" field, find your .bmp file.  Select your class and subclass layer that you want to import to ([Some class]/Silkscreen Top), Check the box next to "Preserve the original dimension of the image" or your logo will not be what you expect (it may not be anyway, see note in all CAPS above....). Click OK. Check your logo.  Save and exit 

5) Open your PCB design file, Place->Components Manually.  Click the Advanced Settings tab.  Check the "library" box (mine took a few seconds to actually fill in the check box). Click the Placement list tab, select "Mechanical Symbols" from the drop down box. The file name of your logo should be in the list (if it's not, make sure your logo file is in the same Windows directory as your PCB).  Select the checkbox next to it. Place the logo on the board.

First, props to eDave as I expect Cadence's implementation is probably based upon his skill.

Next, if you import the logo directly into a library part you'll be able to manipulate it's size and layers there using "create detail" for scaling. I have created a single part that contains 3 different size logos by using different layers: Board_Geometry/Logo_0p5, /Logo_1, /Logo_2 for instance. I can load this into any design and specify which of the layers to include in the artwork definition.

First, props to eDave as I expect Cadence's implementation is probably based upon his skill.

Next, if you import the logo directly into a library part you'll be able to manipulate it's size and layers there using "create detail" for scaling. I have created a single part that contains 3 different size logos by using different layers: Board_Geometry/Logo_0p5, /Logo_1, /Logo_2 for instance. I can load this into any design and specify which of the layers to include in the artwork definition.