Image reproducing apparatus and image reproducing method

Abstract

An image reproducing device and an image reproducing method that can control a brightness and / or a contrast of a sub image according to a brightness and / or a contrast of a main image and minimize eyestrain of users are provided. The image reproducing device comprises an image signal inputting part for receiving input of a first image signal; a sub image signal generating part for generating a sub image signal from information on a sub image extracted from the above-mentioned first image signal; a main image signal decoding part for extracting a main image signal from the above-mentioned first image signal and decoding the above-mentioned main image signal; a brightness detecting part for detecting a brightness of the above-mentioned main image signal and calculating a brightness average value; a brightness adjusting part for adjusting a brightness of the above-mentioned sub image signal based on the above-mentioned brightness average value; an image signal composing part for synchronizing the above-mentioned main image signal and the above-mentioned sub image signal, the brightness of which is adjusted, composing them and generating a second image signal; and an image signal outputting part for outputting the above-mentioned second image signal.

Description

TECHNICAL FIELD [0001] The present invention relates to an image reproducing device and an image reproducing method. BACKGROUND ART [0002] Computerized data stored in a recording medium such as DVD (hereinafter referred to as “content”) and the contents distributed from dynamic image distribution servers or digital video broadcast are as diverse as movies, concerts and sports. The image signal of movie content among these contents includes sub image information such as subtitles in addition to a main image signal compressed according to MPEG2 system. [0003] Unexamined Patent Publication Hei 4-354480 discloses a prior art brightness control circuit. The prior art brightness control circuit receives input of an image signal of cinema scope size (there is a black part of predetermined size on each of the upper and lower sides of an image of a main part and a subtitle appears in the lower black part), detects the subtitle part of the image signal when the image signal reaches a continuo...

AI Technical Summary

Benefits of technology

[0007] The image reproducing device of the present invention adjusts the brightness of the sub image signal based on the brightness average value of the main image signal. That is, when the main image signal is bright, the brightness of the sub image signal is adjusted to be high and when the main image signal is dark, the brightness of the sub image signal is adjusted to be low. Further, the device composes the main image signal and the sub image signal, the brightness of which is adjusted, and outputs the composed signal. The present invention has the effect of realizing the image reproducing device for outputting an image signal that does not cause much eyestrain and is easily viewable for users. The “brightness average value” may be the brightness average value of the whole region where the image signal is displayed (valid region) or the brightness average value of a predetermined region located at a predetermined position of the valid region. Preferably, the “predetermined position” is a center part of the valid region.

[0024] When the brightness of the sub image signal varies subtly at every moment according to the variation in the brightness of the main image signal, users feel inconvenience and suffer much eyestrain. On the other hand, in the case where the brightness average value of the main image signal varies abruptly, when a delay in brightness variation of the sub image signal occurs, users have a visually uncomfortable feeling. The present invention has the effect of realizing the image reproducing device that outputs the sub image signal of stable brightness when the brightness variation of the main image signal is small and varies abruptly the sub image signal at the same timing when the brightness average value of the main image signal varies abruptly.

Problems solved by technology

Therefore, when the brightness and / or contrast of the image of the main part is high (picture is bright and / or sharp), the subtitle part is hard to see because of being relatively dark and / or low in contrast.

On the contrary, when the brightness and / or contrast of the image of the main part is low (picture is dark and / or outline is represented softly), the subtitle part is hard to see because of its glare.

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