The first two steps in the GUI focuses on getting the prerequisite information from the user and the next two steps focuses on the Edge Blending.

The Manual Blending GUI page enables user to do both photometric corrections (brightness adjustments in the overlap region) as well as geometric corrections (angle adjustments of the keystone corners in the projected image).

Step 0 : Prerequisites

Before using the Manual Blending GUI page, please make sure that the following prerequisites are done.

1. The required number of projectors need to be physically set up with the desired overlap region.
2. Make the physical adjustments to the projectors as far as possible to make sure that the projected images are properly overlapped and geometrically aligned.
3. Connect one of the projectors (to be blended) to the Control Program and establish the Command Interface Connection.

When the connection is ready, use the Manual Blending page starting from Step 1 and go in the order of steps.

Step 1 : Read Parameters

(A) Read Output Resolution

This is the first and foremost step in the process of Manual Blending to read the output resolution information from the projector system. The default value of Output Width is 0 and Output Height is 0. Clicking on the "Read Output Resolution" button populates the valid (>0) output resolution information if and only if the connection to the projector system has been established.

When the output resolution information has been read from the projector system, all other GUI elements that are relevant for the next step of action are enabled.

Note: Unless the output resolution information is populated, none of the following functionalities in the GUI would work as expected.

(B) Read Blending Data (Optional)

The user is given two options to either to read the manual blending parameter values stored in the EEPROM and populate into the fields in the page using the button "Load Blending Parameters and Geometric Correction Values from EEPROM" or manually enter data in the GUI in Step 2. When the blending parameter values from the EEPROM are loaded in the GUI, then the user can apply the same on the screen by clicking on the "Initialize and Apply" button in Step 2.

Step 2 : Initialization of Blending Parameters

This step focuses on getting multiple system information from the user to initialize the parameters that are required for edge blending in the following steps. The user is supposed to enter the following information:

Projectors Layout

Layout in which the projectors are arranged, that is, horizontally stacked (columns) or vertically stacked (rows) to combine the projected image.

Based on the values provided by the user, the table of rows and columns depicting the projector layout in the sections "Current Projector in the Layout", "Black Luminance Values (Nits)" and "White Luminance Values (Nits)" is changed to give a visual prepresentation of the projectors layout.

Current Projector in the Layout

In the table of rows and columns depicting the projectors layout, identify the projector system that is currently being blended, that is, the projector system to which the current instance of control program is connected to.

Input Source

Select the input source used to display the pattern or image that should be used for calibration. This calibration patternor image must match the output resolution of the system identified in Step 1.

By default, "Splash Pattern" is the input source that displays a built-in default calibration pattern used for the Manual Blending process.

If "External Source" is the input source selected, then the user is expected to display a custom calibration pattern through External Video Input. The option to "Keep the display as is" makes it so no updates are made to the display. This is the most useful option for quickly tuning the RGB values for Simple 1D RGB mode.

Overlap Information

The user is allowed to give the overlap and fusion zone information in either exact number of pixels or lines or as a percentage in both horizontal and vertical directions.

When the "Projectors Layout" has

• More than one row, then the user must enter the "Vertical Overlap Height".
• More than one column, then the user must enter the "Horizontal Overlap Width".

The GUI controls are disabled when those values are not needed or used.

1. Note: The minimum overlap supported is 1%.
2. "Corner" systems can support a maximum overlap of 60%.
3. "Non-Corner" systems (edge or middle systems) can support a maximum overlap of 49%.

Photometric Correction Mode

For 2D cases and cases that include warping, "Use Black / White Luminance Values" must be selected. For 1D cases without warping, "Use Simple 1D RGB Gain / Offset Values" can be chosen.

Black Luminance Values (Nits)

• Required for 2D Luminance mode.
• The black luminance values of all the projectors in the layout are entered in the table here.
• The black luminance value for the current projector that is being calibrated is highlighted.
• The minimum value and default value is 0.0000.
• Floating point values are supported up to 4 decimal places.
• The maximum value cannot be greater than or equal to the white luminance value of the corresponding projector, that is, 0 ≤ Black Luminance Value < White Luminance Value of the corresponding projector.

White Luminance Values (Nits)

• Required for 2D Luminance mode
• The white luminance values of all the projectors in the layout are entered in the table here.
• The white luminance value for the current projector that is being calibrated is highlighted.
• The default value is 1000.0000.
• Floating point values are supported up to 4 decimal places.
• The minimum value cannot be less than or equal to the black luminance value of the corresponding projector, that is, 0 ≤ Black Luminance Value < White Luminance Value of the corresponding projector.

Simple 1D RGB Values

The RGB gain and offset values for the projector are entered in the below fields. The acceptable range of values are between 0 and 1 for all fields. TI recommends starting with the gain fields as all 1, and the offset fields as all 0. The gain values should be lowered so that a white field appears to be the same brightness as the least bright projector in the system. Raise the offset values to where the black field brightness of all projectors is the same.

After all of the above values are entered, click the "Initialize and Apply" button to initialize all the blending parameters and apply the values on the screen.

Step 3 : Geometric Correction

After the blending parameters are initialized, the user is allowed to perform the geometric correction only for the keystone corners.

• When the user changes any of the keystone corner values, then the updated values are sent through the ESW commands to the projector system and the immediate visual change can be seen on the projected pattern/image on the screen.
• Clicking on the "Reset to Default Values" button would revert all the value changes done so far to their corresponding default values.
• Clicking on the "Enable Edge Blending" button enables the user to enable the edge blending in the overlap region of the pattern displayed, that is, the lines in the pattern on the overlap region will not look sharper.
  • By default, Edge Blending will be disabled to ensure that the user first makes the geometric correction with the sharper looking lines in the pattern on the overlap region.
  • When the geometric correction is done, then the user can click on this button to enable the edge blending in the overlap region.
  • When the edge blending is enabled, this button will be toggled to "Disable Edge Blending".

Step 4: Enter Adjacent projector Geometric Parameters

For the 2D Luminance mode algorithm to correctly calculate the shapes of the overlapping regions, the keystone values of the adjacent projectors must be entered. The values can remain at default (unwarped) until all projectors in the system have completed the warping phase

Step 5:Apply Manual Blending Corrections to EEPROM

1. When satisfied with the manual blending corrections done so far and ready to store it in the EEPROM, choose if the blending data to be stored in EEPROM needs to be applied at startup or not. This can be done by using the "Enable Blending At Startup" checkbox. By default, this check box is unchecked.
   • If the checkbox is checked, then the blending data stored in EEPROM is applied at system startup.
   • If the checkbox is unchecked, then the blending data stored in EEPROM are hot applied at system startup.
2. Click the "Save to EEPROM" button to write the manual blending parameter values in the page to the EEPROM and apply it at startup or not based on the "Enable Blending at Startup" check box state.