How to use EyeCalculus
EyeCalculus includes a number of visual assistance tools. The application can operate in three different modes:
- Identify the color
- Compensate for color deficiency
It is possible in all modes to save the current picture, in it's current state, using the camera icon. The picture is stored in your Camera roll.
The lamp icon is present on devices that have a torch, or camera lamp, such as iPhone 4.
This control turns the torch on and off. Remember that the lamp use a lot of battery.
Shake the device at any time to force the camera to re-focus.
Identify the color
This feature identifies the color in the center of the square. The color is presented by name. The number of names that is searched for can be configured in the Settings part. The default when the app is installed is to search 30 colors. It is also possible to limit the colors to the basic prime colors (9 colors), as well as a more detailed range (134 colors).
It is also possible to have the name of the color spoken out loud by pressing the Speaker button.
In order to get the best results it is important to have good light. On devices with a torch this helps a lot on shorter distances.
Another parameter that is important, and difficult to handle, is called White balance. In short it tries to compensate for the color of the light-source in order to make white items look white.
In the upper right corner is a button to control white balance. By default it is set to AUTO meaning that the device tries to judge the color of the lightsource and compensate for it. Other options are Tungsten, normal lightbulbs, and Fluorescent light.
When AUTO is choosen the device constantly adjusts the white balance. Beneath the AUTO button is then an indication of wether the white balance is unlocked (constantly adjusting) or locked.
It is possible to lock the cameras white balance. This can be used if you have a white or grey item. Turn the camera to the white or grey item and wait for the camera to adjust its white balance until the color shown is correct. Then lock the white balance. It is important that the surrounding light in not changed once the white balance is locked, as this will give incorrect color readings.
Compensate for color deficiency
Around 7-8 % of males and 0.5 % of females have some kind of color deficiency. Depending on the deficiency certain combination of colors can be indistinguishable. Using the Compensate for color deficiency feature of EyeCalculus, it adjusts the part of the color spectrum that is affected making patterns visible that would otherwise be hidden. A total of six modes exist and are changed with the button in the upper right corner of the screen.
The first three modes uses a method called Daltonization based on the work of John Dalton. It increases the contrast of the selected colorspace and remaps colors into the visible space based on deficiancy.
The next three modes turns the picture into greyscale with the exception of the selected base color (red, green or blue) that retains its hue but flashes periodically to indicate its presence.
The following section describes the different viewing modes available.
Compensate for the lack of, or reduced function of L-cones. The L-cones cover the Long wavelength spectrum. When people have problems to distinguish between colors in the green-yellow-red part of the spectrum. The protanope may experience strong reduction of brightness due to the reduced intake of the Long wavelength spectrum. This abnormal dimming may lead to that reds are mistaken for black.
Compensate for the lack of, or reduced function of M-cones. The M-cones cover the Medium wavelength spectrum. When people have problems to distinguish between colors in the green-yellow-red part of the spectrum. Common to the protanope the deuteranope does not experience the dimming effect.
Compensate for the lack of, or reduced function of S-cones. The S-cones cover the Short wavelength spectrum. When people have problems to distinguish between colors in the blue-yellow part of the spectrum.
This mode turns the image into greyscale except for red colors. The red content of the picture maintains its hue and flashes periodically to indicate its precense.
Same function as above but isolates the green content of the picture.
Same function as above but isolates the blue content of the picture.
The magnify feature works as a digital magnifying class. Depending on the device up to 8 times magnification is supported. It is possible to step through the magnification levels by pressing the magnify button or by using the pinch gesture on the screen. When the magnification level exceeds 5 times a sharpening algorithm is applied. This may create extra noise as information is added to the image that was not present. It is possible to turn off this sharpening in the Settings.
The magnified image can be presented in three different ways. In the upper right corner of the screen is the button to toggle between the presentation modes.
Present in color
In this mode the image is presented in normal color.
Present in grey scale
In this mode the image is presented in grey scale.
Present in inverted grey scale
In this mode the image is presented in inverted grey scale. For people with photophobia (excessive sensitivity to light) this can help reading text printed on white paper by making the background black and the text white. Thereby lowering the total amount of light for the eye.
Switch between normal and strong contrast.
When this feature is turned on the color spectrum is drawn to the extreme parts. I.e. light items will be lighter and dark items will be darker. Increasing contrast may increase noise levels but can help significatly in readability of text and symbols.
In the settings screen it is possible to control certain behaviors of EyeCalculus.
Button sounds - turns on and off the audio feedback of buttons on the main screen.
Extra Voice over feedback - gives some extra feedback on some actions, without the need for enabling the full built in voice over functionality of iOS.
Show Camera Focus and Exposure indicators - controls whether visual indicators are shown when the camera is adjusting focus and exposure levels. Knowing if the camera is adjusting the exposure can be of interest when identifying colors. The focus indicator can be used to know if the camera is trying to adjust focus or has given up (maybe due to the near focus limit).
Use sharpening on higher magnification levels - controls whether artificial sharpening should be applied at higher magnification levels. This may increase the noise levels of the image but can help. Best used with a strong light source or the built in torch at close distance.
Number of color names - select the number of symbolic color names searched for when identifying colors. Depending on the use it may be more important to know that the color is Red (or reddish) rather than orange red. The fewer colors searched the bigger the error.
Feedback is welcome!
While this app was developed to help the people around us in their daily lives you may have ideas or things that would make EyeCalculus do more. Please send us an email with ideas or feedback to firstname.lastname@example.org