Moving image processing apparatus and moving image processing method
AssigneeCanon Kabushiki Kaisha
InventorKiwamu Kobayashi
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Abstract
In order to distribute low-frequency component image data L in image data for one frame to first and second sub-frames respectively as L1 and L2, a distribution of L2 in the low-frequency component image data L is decided. This decision is made based on a non-linear curve, so that when the low-frequency component image data L falls within a low-level region, a distribution rate of L2 is decreased, and when the low-frequency component image data L falls within a high-level region, the distribution rate of L2 is increased within a range that does not exceed 0.5. In this way, a negative-side clipping phenomenon of high-frequency components is suppressed in the low-level region, and flickers are suppressed in the high-level region.
Claims15
A moving image processing apparatus which concentrates high-frequency components in image data for one frame on a first sub-frame, and distributes low-frequency components to the first sub-frame and a second sub-frame upon generating image data of two sub-frames based on the image data for one frame, said apparatus comprising:
- an extraction unit configured to extract low-frequency components L from image data of a frame of interest;
- a distribution unit configured to decide a distribution of second low-frequency components L2 in the low-frequency components L so as to distribute the low-frequency components L to the first sub-frame SH and the second sub-frame SL as first low-frequency components L1 and the second low-frequency components L2;
- a first sub-frame generation unit configured to generate the first sub-frame SH as a sum of the first low-frequency components L1 in the low-frequency components L and high-frequency components H in the frame of interest by subtracting the second low-frequency components L2 from the image data of the frame of interest;
- and
- a second sub-frame generation unit configured to generate the second sub-frame SL based on the second low-frequency components L2,
- wherein when a level of the low-frequency components L falls in a low-level region in which the level is lower than a predetermined boundary level, said distribution unit sets a distribution rate of the second low-frequency components L2 to be relatively smaller than when the level of the low-frequency components L falls within a high-level region in which the level is higher than the boundary level, and when the level of the low-frequency components L falls within the high-level region, said distribution unit sets the distribution rate of the low-frequency components L2 to be relatively larger within a range that does not exceed 0.5 than when the level falls within the low-level region.
A moving image processing method which concentrates high-frequency components in image data for one frame on a first sub-frame, and distributes low-frequency components to the first sub-frame and a second sub-frame upon generating image data of two sub-frames based on the image data for one frame, the method comprising:
- an extraction step of extracting low-frequency components L from image data of a frame of interest;
- a distribution step of deciding a distribution of second low-frequency components L2 in the low-frequency components L so as to distribute the low-frequency components L to the first sub-frame SH and the second sub-frame SL as first low-frequency components L1 and the second low-frequency components L2;
- a first sub-frame generation step of generating the first sub-frame SH as a sum of the first low-frequency components L1 in the low-frequency components L and high-frequency components H in the frame of interest by subtracting the second low-frequency components L2 from the image data of the frame of interest;
- and
- a second sub-frame generation step of generating the second sub-frame SL based on the second low-frequency components L2,
- wherein in the distribution step, when a level of the low-frequency components L falls in a low-level region in which the level is lower than a predetermined boundary level, a distribution rate of the second low-frequency components L2 is set to be relatively smaller than when the level of the low-frequency components L falls within a high-level region in which the level is higher than the boundary level, and when the level of the low-frequency components L falls within the high-level region, the distribution rate of the low-frequency components L2 is set to be relatively larger within a range that does not exceed 0.5 than when the level falls within the low-level region.
Dependencies are inferred from the claim text.