Patent Grant
7417641
Conventional aeronautical chart files provided by such manufacturers as Jeppesen Sanderson, Inc. of Denver, Colo. are configured for charting on paper and possibly for displaying on conventional personal computers (PCs). Such conventional aeronautical chart file information is not tailored for avionics quality displays which may be used in a cockpit or other location inside an aircraft. Also, conventional aeronautical chart files are not tailored for displaying on most conventional electronic displays.
Aeronautical chart files are conventionally created using RGB colors, fonts, and graphics rendering techniques for personal computers, in order to achieve high quality paper charts. The result of displaying such conventional aeronautical chart files on an electronic display, such as, but not limited to, an avionics quality or commercial quality display, results in reduced readability, especially in cockpit ambient illumination conditions, and reduced color contrast compared to paper charts. In particular, for liquid crystal displays (LCDs), characteristics may also include color shifts over a range of viewing angles and poor font quality.
Accordingly, there is a need for a system and method to convert aeronautical chart files into files which are usable in an avionics quality display environment. There is also a need for a method of remapping conventional aeronautical chart colors to colors which will be more readily usable, readable, and provide better contrast and reduced luminance for an avionics quality display. Further, there is a need for a method and apparatus for remapping a white background color to a background color that does not conflict with other chart features and that provides color contrast for sunlight, diffused light, and night viewing conditions, as well as providing reduced luminance while maintaining good color contrast. Further still, there is a need for a system and method for using conventional aeronautical chart data and remapping conventional fonts and line widths to appropriate fonts and line widths for improved readability on an avionics quality display.
It would be desirable to provide a system and/or method that provides one or more of these or other advantageous features. Other features and advantages will be made apparent from the present specification. The teachings disclosed extend to those embodiments which fall within the scope of the appended claims, regardless of whether they accomplish one or more of the aforementioned needs.
An example of the invention relates to a method of converting electronic display aeronautical chart data to aeronautical chart data tailored for an avionics quality display. The method includes receiving by a data processing unit, electronic display aeronautical chart data. The method also includes remapping the color palette of the electronic display aeronautical chart data, to improve viewability on the avionics quality display. Further, the method includes sending signals representative of the remapped colors to the avionics quality display.
Another example of the invention relates to a method of converting an aeronautical chart file to an avionics display file. The method includes remapping the background color of an aeronautical chart file to a display background color having subdued background luminance.
Yet another example of the invention relates to a computer readable medium, having a program stored thereon. The program includes a first set of instructions to remap the background color of an aeronautical chart file to a display background color having subdued background luminance and a second set of instructions to store data representative of the display background color in an avionics display file.
Alternative exemplary embodiments relate to other features and combination of features as may be generally recited in the claims.
The invention will become more fully understood from the following detailed description, taken in conjunction with the accompanying drawings, wherein like reference numerals refer to like elements, in which:
Referring now to
However, it is desirable to display chart information on an avionics display integrated into the aircraft cockpit or other location on the aircraft. Such an avionics quality display needs to meet certain desired characteristics, such as, but not limited to, readability, especially providing color contrast for sunlit, diffuse sunlit, and night viewing conditions as well as reduced luminance of the display such that the background color of the aeronautical chart shown on the display does not provide an undesired brightness within the flight cabin when flying at night. Accordingly, aeronautical chart data 100 may be remapped in terms of colors, fonts, and line widths (operation 130) by an on-board computer or other data processing device which may be on-board or not on-board the aircraft. Once the colors, fonts, and line widths have been remapped, the aeronautical chart data, in a preferred display format, will be displayed on the avionics quality display (operation 140) in the cockpit or other locations on-board the aircraft.
Referring to
In an exemplary embodiment, the color remapping referred to in operation 130, which may be carried out by processor 210 or another computer which is not on-board the aircraft, uses the color palette chart shown below to remap the colors, in the aeronautical chart data, to colors for the avionics quality display. The color palette chart below depicts the original aeronautical chart color palette and the remapped target color palette. For example, the fourth row of the table corresponds to the aeronautical chart color Red having RGB values of 255, 000, and 000, respectively. This is remapped into a PC based platform color having RGB values of 192, 000, and 000, with a target platform color having Hex value of 0000C0 and is typically used for airport diagram hot spots. The color red also corresponds to a chromaticity value of u′=0.4272, v′=0.5184, and fL=5.42.
In an exemplary embodiment, in order to implement a color remapping of the type described, RGB values in the original chart file may be remapped in terms of gray scales that result in color, color contrast, and color saturation differences representative of those in paper printed charts. When the gray scales are remapped, it is beneficial to have the gray scales providing more separation and a more linear relationship thereby providing better contrast and more uniform separation.
Once the colors are remapped, the chart feature chromaticity can be measured on the target platform to confirm that they are consistent with the color palette that is desired. Also, the typically white background that is used in conventional paper aeronautical charts is remapped into a preferable gray-green color or another color that does not conflict with chart features and that provides color contrast for sunlight, diffuse sunlight, and night viewing conditions. In a preferred embodiment, chromaticity coordinates are u′=0.1778, v′=0.4235, and fL=33.26 (see, last row of Summary Chart Color Palette). However, other colors may be used having other chromaticity coordinates that provide the desired background and contrast, without departing from the scope of the invention.
Once the chromaticity coordinates are defined, an interwoven elemental spatial modulation pattern for the chart background is defined and implemented. In preferred embodiments, the implementation of the gray-green background color reduces the luminance of the background by approximately 22% and facilitates the color stability of the chart features. Further, in an exemplary embodiment, new font types are defined and implemented for the avionics display that preferably maintain the original chart file font style. Also, an algorithm may be implemented that dynamically displays a given font at a given line width depending on the point size displayed, and redefines the line widths for chart features (e.g., for terrain contours). In an exemplary embodiment, a relationship may be developed between font point size and line width in order to provide the proper character lines such that they are perceived to be the correct line width, that is, the line width of the corresponding font in the original aeronautical chart. Such a relationship may be, but is not limited to, line width=(point size×K)+C where K and C are defined constants. In an exemplary embodiment, the constants may be defined according to the font being used, for example, as shown in the table below.
Similarly, as can be seen in the chart, other mappings are done. Further, for some mappings, no remapping is necessary. For example, in the first row, RGB values of 000,000, and 000, there is no corresponding remapped color in the remapped color palette because no remapping was necessary for the color Black.
In an exemplary embodiment, remapping of the color palette from the original aeronautical chart file to the aeronautical chart file which is tailored for the avionics quality display, requires a remapping of the background color. Preferably, the remapped background color is a green, a gray, or a gray-green color especially in the case that the original aeronautical chart background color was substantially white. The use of a gray-green background color provides an avionics display having reduced luminance over a white background color. Accordingly, the display will not appear too bright in the flight cabin. Further, the gray-green color provides good contrast with other chart feature colors. In an exemplary embodiment, no other chart feature colors are close to the gray-green background color.
In a preferred embodiment, an interwoven elemental spatial modulation pattern is used to implement colored pixels on an avionics quality display. For example, an interwoven elemental spatial modulation pattern 500 is depicted in
Referring back to
Accordingly, referring to
While the detailed drawings, specific examples and particular formulations given describe preferred and exemplary embodiments, they serve the purpose of illustration only. The inventions disclosed are not limited to the specific forms shown. For example, the methods may be performed in any of a variety of sequence of steps. The hardware and software configurations shown and described may differ depending on the chosen performance characteristics and physical characteristics of the computing and display devices. For example, the type of computing device, communications bus, processor, or display hardware used may differ. The systems and methods depicted and described are not limited to the precise details and conditions disclosed. Furthermore, other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the exemplary embodiments without departing from the scope of the invention as expressed in the appended claims.
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