So I have this picture:
If I print the picture, when I print this the mountain behind is around 1.3cm and the car in the lower left is around 0.4cm. I dont know how far away the car is from the mountain but I would like to know if there is a way to know how big would the car be if it were on top of the mountain. Please help me.
What you need to compute this is the distance between the camera and the car and the distance between the camera and the volcano (Mt. Fuji?). This is not easily found from the image itself, but if you can find the place where the image is taken in an aerophoto service such as Google Maps*, you might be able to work out the camera position by perspective.
First, the camera is clearly directly above the left side of the street. We also need another line it is on -- for example you might be able to find the red billboard behind the railway line in the areaphoto, and then draw the line that connects it with the traffic light at the right end of the zebra crossing. Since these to objects are directly above each other in the image, the camera was located somewhere on the line on the map that contains both of them.
Once you know where the camera was, measure the distance along the street (which I'll assume is the optical axis of the image) until you reach the point in the street where the angle towards the camera and where the car was. (This looks like it's more or less at the left end of the zebra crossing).
Divide this distance with to the volcano. The resulting ratio is how much smaller the image of the car would been if it was moved up the mountain.
Edit: Looks like it's taken here. The direction of the street matches, and the boxy cream-coloured building to the left is clearly recognizable in Google Street View, but unfortunately the zebra crossing seems to have moved (and the tall smokestack demolished?) after the photo was taken. On the other hand, we can probably conclude anyway that the photo was taken from the Shinkansen viaduct, which also explains the high vantage point, and would be good enough to measure the distance to the parking space where the car stood with a reasonable accuracy.
Edit 2: Definitely taken from the train. Here is the original, and another one from a few meters further left/west, both explicitly documented as "from the shinkansen".
