Specify jpg, tiff, png image size for print PDF.

When to use it?
If we wish to use photo to prepare printable PDF with bleed and crop marks.
What part of PDF is affected by it?
The PDF will consists of an image and the crop marks.
What to watch for?
The resolution of the image should not be less than 300 dpi as much as possible
How to use it?

Dimensions: cropped size of PDF without bleed.

Only a portion of the image is needed for the PDF. Cropping.

The cropped size of PDF is not to scale with the image.

The crop size of PDF will be to scale with the image.