Blue only mode

With blue-only mode is referred to a special mode in display devices ( LCD projector, screen, TV ), in which only the blue pixels or the blue cathode ray tube (old tube technology ) is used to generate the image. Especially in the broadcast sector have display equipment has this mode, since hereby the hue and saturation can be adjusted quickly and accurately. For this is of professional monitors, a separate button on the front of the display device.

Test images

In general, all test images are a color bar, the red, green, blue as well as the complementary colors cyan, magenta and yellow contains, for the blue-only mode and the feasible adjustment of hue and saturation. Particularly frequently, however, the SMPTE test pattern or the HD version of SMPTE color bar is used for setup. These are integrated in the professional sector in many cases already in the recording and playback devices and are available at any time. Even the blue-only test image of the company Burosch audio video equipment is suitable for use with blue filter film or just in the Blue Only mode. In addition to hue and saturation can be customized with the test images mentioned above, the brightness and contrast of the display devices to set. The mentioned Burosch test image presents an update of the conventional HD SMPTE test pattern, with additional test zones for the complete image control and optimization.

Operation

In the blue-only mode, only the blue pixels produce - or at CRT monitors, the blue cathode ray tube - the picture. Thus you can see the blue channel of the image colored blue. Areas of color with blue colors appear bright and those without dark blue. The color blue with the RGB values ​​0 0 255 thus appears bright red area A ( 255 0 0) or a green surface ( 0 255 0), however, appears black. Below - or above in some test images - the color bars are reference areas, with proper adjustment have the same brightness value which must as the related areas of color. If the display device properly adjusted fit in the blue-only mode display, the color space without brightness difference in the reference areas a. When SMPTE HD test image, the reference surface is below the color bar in the form of a gray solid area. With the old SMPTE test pattern, the reference area is also below the individual color bars. The Blue Only test image the company has Burosch respectively above and below the color bar single reference areas for each hue. The following table shows the individual colors, the associated code values ​​and the visual impression in the blue-only mode:

See illustration at right. Blue Only view the ARIB / SMPTE test pattern.

Blue filters instead of blue-only mode

Alternatively, the blue-only mode can be used a cobalt blue filter film in conjunction with the above test images. If you look through this slide, one also sees only the blue portion of the test image. Important when using such films is the transmittance. The films should have a very narrow-band transmittance in the short wavelength region of the visible spectrum and only let through the blue wavelengths of the light spectrum. If we look through the film still other colors, so you can take the films also double. An example of blue filters in conjunction with test images are also the blue filter glasses from THX. Sometimes display devices can also be adjusted with red or green filters. As a result, the color reproduction in all three channels will be properly set.

Adjust saturation and hue

For this one must enable mode, the display device in the Blue Only. If this is not possible, you can - as mentioned above - on blue filters fall back.

• The first is for setting the saturation. To do this, change the value in the menu until the colored bars seamlessly show up, with the same brightness and no apparent difference in the reference areas or below the color bars.
• If the colored bars are no longer differentiated from the reference areas, the saturation is set correctly.
• Next, we now represents the tone correctly.

Often single colored areas still lift on the reference surfaces, or individual colored bars - which should actually be dark - still appear too bright and stand out from the reference surfaces. This particularly for particulate beam cyan and magenta, with under but also the green color bars. In this case you have to adjust the color tone menu until these color bars show in the reference surface perfectly and without any visible difference. In the web links to find more detailed instructions.