Trapezoidal correcting system for projector

Abstract

The present invention relates to a projector trapezium correction system. On the output end of picture current of projector the invented projector trapezium correction system can be adopted to make image processing. Said processing method includes the following steps: firstly, making the picture current be passed through A/D converter circuit to obtain digital signal, after having been processed making the digital signal be passed through D/A converter circuit to obtain analog signal and output it; using FPGA chip as image processing core chip, the FPGA chip is connected with data and control port of microprocessor, utilizing microprocessor to control FPGA to execute operation, said microprocessor has memory, clock and power supply module, image processing software is used for processing video signal, in which pretreatment adopts Kaiser window and Sinc function filter to make filtration, the correction adopts line interpolation algorithm and ZEROPAD edge sawtooth correction technique and signal communication between chips adopts I2C bus connection.

Description

technical field [0001] The invention relates to a new keystone correction system applied in projectors. Background technique [0002] In the use of the projector, the position of the projector should be at right angles to the projection screen as much as possible to ensure the projection effect. If the verticality of the two cannot be guaranteed, the screen will produce a trapezoid. The projector is placed on the table, and it is difficult to guarantee "vertical". In this case, you need to use the "keystone correction function" to correct the trapezoid to ensure that the picture becomes a standard rectangle. There are usually two methods of keystone correction: optical keystone correction and digital keystone correction. Optical keystone correction refers to the purpose of adjusting the trapezoid by adjusting the physical position of the lens, but when the physical position is limited, this method is difficult; digital keystone correction refers t...

AI Technical Summary

Problems solved by technology

[0009] A projector trapezoidal correction system uses the projector trapezoidal correction system to process graphics at the output end of the video stream of the projector, and first passes through the AD conversion circuit for digital processing, especially using the FPGA chip as the image processing core chip, the FPGA chip and the micro The data of the processor is connected to the control port, and the FPGA is controlled by the microprocessor to perform calculations. The microprocessor is equipped with memory, clock and power supply modules, and is processed by using image processing software. The preprocessing uses Kaiser window function and Sinc function filter. Filtering and correction adopt line interpolation algorithm and ZEROPAD edge aliasing correction technology, which solves the contradiction between the correction range and aliasing distortion, and can realize the vertical trapezoidal correction range from -50 degrees to +50 degrees, and the naked eye cannot detect the aliasing noise

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