SPEEDUP RADAR

How it works

The SPEEDUP Baseball app leverages the camera of a smartphone to measure the speed of a baseball. The camera takes high-resolution images of the ball at high speed (several hundred images per second for the most efficient smartphones). Each image is analysed by a complex and innovative image processing algorithm which aims, in a few thousandths of a second, to locate the baseball. Once the ball has been identified, the speed can be estimated by calculating the ratio between the distance traveled by the ball and the time elapsed between two images. Speed measurement is accurate to 3 km/h (2 mph). For comparison, a commercial radar is accurate to around 2 km/h (1 mph). To find out more about accuracy, click on the link below.

How to use it

To measure speed, a user starts by choosing a use case :

Device placed on the ground
- in front of the pitcher
- to the right or left of the pitcher
Device mounted on a tripod

After throwing the ball, the speed is updated in real time on the SPEEDUP Live interface located inside the application and on the SPEEDUP Baseball Live web interface. Any owner of the application who has received the SPEEDUP Live code from the pitcher can consult the speed of the pitch in real time. The pitcher can also activate voice announcement on its smartphone (activated by default).

Accuracy

Device placed on the ground

in front of the pitcher

How to use it

Place the smartphone/tablet flat on the ground, screen facing down, step back about 2 m (6.5 ft) from the device, and throw the ball.

Try your best to keep the trajectory of the ball aligned with the device’s long axis.

Make sure the ball stays within the camera’s field of view represented above by a 1m (3.5ft)-wide corridor.

Maximum speed that can be measured

The maximum measurable speed in this configuration varies depending on the smartphone model :

iPhone: 200 km/h (125 mph)
Android: 80 km/h (50 mph) in general and for some models 160 km/h (100 mph)

For owners of an Android smartphone, a certain number of alternatives exist in order to increase the maximum measurable speed:

choose another use case: “device placed on the ground to the right or to the left of the pitcher” or “device mounted on a tripod”.
If your device allows it, choose “File” mode described in detail below.

N.B.: the minimum speed has been set at 30 km/h (20 mph).

"File" mode

"File" mode is intended to allow owners of an Android smartphone to carry out speed measurements up to 200 km/h (125 mph) in the configuration "Device placed on the ground in front of the pitcher".

As a reminder, the maximum measurable speed in this configuration varies depending on the smartphone models:

iPhone: 200 km/h (125 mph)
Android: 80 km/h (50 mph) in general and for some models 160 km/h (100 mph)

The fact that most Android smartphones fail to measure speeds above 80 km/h (50 mph) in this configuration is due in part to the fact that the image acquisition rates made available to developers of application do not exceed (except for a few rare exceptions) 30 images per second. Assuming that this limitation may be overcome one day, another issue will remain: the insufficient computing capacity of most entry-level Android smartphones to perform real-time processing of images taken by the smartphone camera. If you are an Android user, you can:

choose another use case: "device placed on the ground to the right or left of the pitcher" or "device mounted on a tripod"
if your device allows it, choose "File" mode described in detail below.

Mode of operation

"File" mode consists of two steps:

First, a short video of your pitch is recorded using the slow motion function available in the camera application installed by default on your device (if the slow motion function is not available, you will not be able to use "File" mode)
Secondly, the video recording is provided to the SPEEDUP app in order to extract the characteristics of the trajectory (speed, pitch angle, etc.) of each of the pitches present in the file. Ideally, the duration of a recording should not exceed 15-20 seconds since the time required for SPEEDUP to measure the speed increases with the size of the slow motion video file which can be very large.

N.B.: "File" mode is accessible by selecting the "File" option above the red button on the application home page.

Guidelines

Using "File" mode will yield good results under the following conditions:

The camera application installed by default on the device must allow recording of videos in slow motion (typically, 120/240 frames per second, without interpolation). Super slow-motion, if present, is not recommended.
The device must be placed on as flat a floor as possible (a spirit level may be used in order to check that the surface is level in both the directions of the major axis and minor axis of the device).
The lighting ambiance, natural or artificial, must be of very good quality, which translates into strong luminosity and absence of flickering. Beware of certain LED lighting that is very bright but has strong flickering (clearly visible on a video taken in slow motion). Ideally, the video recording will be carried out outdoors in the middle of the day.
The SPEEDUP app must be installed on the same device that was used to record the slow motion video of the pitch. It is strongly recommended not to analyse a video taken with another device.
In the beginning of a session, place the device on the ground within 2-3 seconds after pressing the camera button, and eave the camera\'s field of view as soon as possible.
After your last pitch, wait at least for 3 seconds before taking the device back in your hand, and press the stop button as soon as possible.

N.B.: "File" mode was tested with a samsung device (A25 5G). If you experience any trouble with another device model, please feel free to get back to us at : speedup.baseball@gmail.com

Device placed on the ground

to the left or the right of the pitcher

How to use it

The smartphone is placed on the ground to the right or the left of the pitcher at a distance D from the throwing axis ranging between 1m and 2.5m. The rear camera points in the direction of the ball.

Adjust the angle between the smartphone and the ground so that the trajectory of the ball enters the camera's field of view.

The pitcher should not be located within the camera's field of view when pitching as this may interfere with the speed measurement.

Maximum speed that can be measured

iPhone: 200 km/h (125 mph) regardless of the distance D ranging between 1m and 2.5m. For optimal performance, it is recommended to choose a value between 1m and 1.5m (performance in terms of detection and measurement accuracy increases when the distance D decreases).

Android: For the majority of Android smartphones, the maximum measurable speed increases with distance as shown in the table below. For some models, the maximum measurable speed is 160km/h (100mph) regardless of the distance D between the smartphone and the throwing axis, ranging between 1m and 2.5m

Device MOUNTED ON A TRIPOD

How to use it

The smartphone is fixed on a tripod at a distance D from the throwing axis ranging between 1.5m and 3m. The rear camera points in the direction of the ball.

The pitcher should not be located within the camera's field of view when throwing the ball as this may interfere with the speed measurement.

Maximum speed that can be measured

iPhone: 200 km/h (125 mph) regardless of the distance D ranging between 1.5m and 3m. For optimal performance, it is recommended to choose D between 1.5m and 2m (performance in terms of detection and measurement accuracy increases when the distance D decreases).
Android: For the majority of Android smartphones, the maximum measurable speed increases with distance as shown in the table below. For some models, the maximum measurable speed is 160km/h (100mph) regardless of the distance D between the smartphone and the throwing axis, ranging between 1.5m and 3m.

Good to know

Lighting conditions

Lighting conditions may have a significant impact on the speed measurement quality since the app relies on the camera to measure the speed of the ball. Currently, the app performs best outdoor in daylight as well as indoor in environments with good lighting conditions (bright and flicker-free lighting). Whether outdoor or indoor, should the lighting quality be too low, it is recommended to use an auxiliary lighting. If you are experiencing poor lighting, click on the button below to find out how to improve your speed measurement experience.

False trajectories

Disturbances in the camera's field of view may cause the speed measurement algorithm to produce a speed measurement while no ball was travelling in front of the camera. Even though the SPEEDUP technology was designed to filter out most of the real-world disturbances, make sure the camera's field of view does not contain a high level of visual pollution. In the event a false trajectory is detected, the speed measurement information produced by the algorithm may be ignored.

LIght source location

When the light source (e.g., the sun or an artificial source of light) is located in front (resp. at the back) of the camera, the ball appears generally dark (resp. bright) on the image since approximately only half of the ball is exposed to the light source. This fact must be taken into account when setting up a speed measurement session. As a rule of thumb, when the source of light is located in front (resp. at the back) of the camera, make sure that the background scene is not too dark (resp. not too bright) in order to maximize the contrast between the ball and the background (the speed measurement quality depends significantly on the contrast between the ball and the background scene, as they appear on the image).

Ball's characteristics

The SPEEDUP Baseball app was designed and optimized with the aim of measuring the speed of a baseball. Using the app with balls significantly larger or smaller than a baseball will result in erroneous speed measurements. The diameter of the ball is assumed to lie in the range 2.78-3 inches (73-76 mm).

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