Search results
27 lis 2022 · Make approximate measurements in an image, using an object with known size for scale. Online, without upload, simple and free. For the best accuracy, the objects should be close to each other — unlike in the sample image below.
This is a convenient online ruler that could be calibrated to actual size, measurements in cm, mm and inch, the upper half is the millimeter ruler and centimeter ruler, the lower half is an inch ruler.
Visual Angle Calculator. The visual angle of an object is a measure of the size of the object's image on the retina. The visual angle depends on the distance between the object and the observer -- larger distances lead to smaller visual angles.
Calculate Distance or Size of an Object in a photo image. This is rather specialized, but people do ask how to determine or measure the distance or size of an object or subject in a photo image.
Calculating the object size or FOV using entocentric standard lenses. Calculate the field of view given the working distance, sensor size and lens focal length.
Canonical Visual Size for Real-World Objects. Talia Konkle and Aude Oliva. Massachusetts Institute of Technology. Real-world objects can be viewed at a range of distances and thus can be experienced at a range of visual angles within the visual field.
If one looks at a one-centimeter object at a distance of one meter and a two-centimeter object at a distance of two meters, both subtend the same visual angle of about 0.01 rad or 0.57°. Thus they have the same retinal image size R ≈ 0.17 mm {\displaystyle R\approx 0.17{\text{ mm}}} .
