The U.S. Patent and Trademark Office officially published a series of 63 newly granted patents for Apple Inc. today. In this particular report we cover Apple's win for an iPhone that could take photos underwater. While the iPhone has been able to work under 6 feet of water, Apple is now talking up to 10X that depth.

Apple's granted patent covers a waterproof iPhone that provides an image sensor that may capture images of underwater objects. Technically speaking, the iPhone described in this granted patent would be able to work when scuba diving  as it could function in water up to 60 feet deep.

The spectral absorption of water tends to turn underwater ambient lighting conditions greenish. Control circuitry in the submersible iPhone could perform color balancing operations and take other actions to compensate for this change in ambient lighting.

Sensors such as an ambient light sensor, a depth sensor, a distance sensor, an orientation sensor, light-emitting and detecting devices, and other circuitry may be used in determining color balance adjustments and other image adjustments to make for underwater images.

The sensors may include a color ambient light sensor. The color ambient light sensor may be used in measuring ambient light spectra above water and under water. Information from the ambient light sensor may be used in determining a light absorption spectrum for water. The ambient light sensor may also be used in measuring ambient lighting conditions above water.

A depth sensor may be used in measuring the depth of the image sensor and other components of the iPhone when operated under water. Information on the depth of the image sensor, information on the distance of an underwater object to the image sensor, angular orientation information for the electronic device and image sensor, and/or other information may be used in color balancing an image.

Water murkiness measurements and/or information on distance between the image sensor and an underwater object may be used in adjusting image contrast.

Apple's patent FIG. 1 below is a schematic diagram of an iPhone device having an image sensor; FIG. 2 is a front perspective view of an iPhone with an image sensor; FIG. 3 is a rear perspective view of an iPhone with an image sensor; FIG. 5 is a diagram of illustrative contrast levels that may be established as a function of measured depth underwater and image-sensor-to-object distance. 

Apple's patent FIGS. 9 and 10 above are flow charts of illustrative operations involved in gathering information associated with underwater lighting and image capture operations.

Apple further notes that digital cameras are sometimes provided with an automatic white balance function that estimates a satisfactory color correction to apply to captured images so that the apparent color of the images is pleasing to the eye (e.g., so that neutral image tones appear neutral to a viewer).

Water tends to absorb red light, so that ambient light becomes greenish under water. This greenish ambient light deviates from the Planckian locus on which the chromaticity of usual light sources is located, so that conventional automatic white balance adjustments, which assume that light sources are on or near the Planckian locus, tend to produce unsatisfactory results (e.g., greenish underwater scenes are confused with green lawns or forest scenes and incorrect color balance adjustments are made). Here, color balance adjustments include white balance and color rendering for non-achromatic colors.

These shortcomings can be addressed by using the sensors and other data gathering capabilities of an iPhone to characterize underwater ambient lighting conditions.

Actions can then be taken based on the characterized underwater conditions. For example, color balance for still and/or moving images can be adjusted, compensating reddish illumination may be produced to help adjust the color of target objects in an underwater scene, a reddish filter may be switched into use, etc.

The murkiness of water due to chemicals, plankton, and other materials can lead to undesired reductions in image contrast.

In some arrangements, the iPhone may use light backscattering measurements or other measurements to characterize the amount of murkiness that is present in an underwater environment. Appropriate action can then be taken based on the measured amount of murkiness and/or the distance between the image sensor of device 10 and the target object. For example, contrast can be enhanced to compensate for the loss of contrast in captured images due to murky water.

Apple tries to never limit a patent to one single device and in this patent it's no different. While the iPhone is the focal device, Apple notes that the technology could apply to a future Apple Watch, smartglasses and more.

Apple notes that images captured with a submersible camera may have an undesired greenish color cast.

Apple's granted patent 10,785,384 was originally filed in Q3 2017 and published today by the US Patent and Trademark Office.