Image Processing, Segmentation, Object Detection, Measurement, Calibration.
in details 4. The sizes in pixel and DPI of image is mentioned over there From Image properties There is a second option if you can’t see DPI from first method. The second method is 1. Go to your 3D paint application from windows button 2. Open image in paint 3. Click CRTL+ E 4. You will see DPI of