Noise removing circuit, image sensing device and operation method of the same
AssigneeSK hynix Inc.
InventorsDong Ik Kim, Jin Su Kim, Chang Ki Min, Seong Hee Park
Life of this patent
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Abstract
A noise removing circuit includes an image combiner suitable for generating a high dynamic range (HDR) image by combining images having different exposure times; a detailed image generator suitable for generating a detailed image from the HDR image; an image strength evaluator suitable for evaluating strength of the detailed image; and a noise coring component suitable for performing a noise coring operation for removing noise from a region of the detailed image in which a signal to noise ratio (SNR) has decreased using a low threshold and a saturation threshold when the strength of the detailed image is less than a reference value.
Claims14
A noise removing circuit, comprising:
- an image combiner suitable for generating a high dynamic range (HDR) image by combining images having different exposure times;
- a detailed image generator suitable for generating a detailed image from the HDR image;
- an image strength evaluator suitable for evaluating strength of the detailed image;
- and
- a noise coring component suitable for performing a noise coring operation for removing noise from a region of the detailed image in which a signal to noise ratio (SNR) has decreased using a low threshold and a saturation threshold when the strength of the detailed image is less than a reference value,
- wherein the noise coring component adjusts a noise coring strength using a coring width parameter in a first region in which a long exposure image and a middle exposure image overlap and a second region in which the middle exposure image and a short exposure image overlap.
An image sensing device, comprising:
- an image sensor including a pixel array having a plurality of pixels;
- an image signal processor suitable for processing an output signal of the image sensor;
- and
- a noise removing circuit including:
- an image combiner suitable for generating a high dynamic range (HDR) image by combining images having different exposure times;
- a detailed image generator suitable for generating a detailed image from the HDR image;
- an image strength evaluator suitable for evaluating strength of the detailed image;
- and
- a noise coring component suitable for performing a noise coring operation for removing a noise from a region of the detailed image in which a signal to noise ratio (SNR) has decreased using a low threshold and a saturation threshold when the strength of the detailed image is less than a reference value,
- wherein the noise coring component adjusts a noise coring strength using a coring width parameter in a first region in which the long exposure image and the middle exposure image overlap and a second region in which the middle exposure image and the short exposure image overlap.
An operation method of an image sensing device, comprising:
- generating a high dynamic range (HDR) image by combining a long exposure image, a middle exposure image and a short exposure image;
- generating a detailed image from the HDR image;
- evaluating strength of the detailed image;
- and
- performing a noise coring operation for removing noise from a region of the detailed image in which a signal to noise ratio (SNR) has decreased using a low threshold and a saturation threshold when the strength of the detailed image is less than a reference value,
- wherein the low threshold indicates a first region in which the long exposure image and the middle exposure image overlap, and the saturation threshold parameter indicates a second region in which the middle exposure image and the short exposure image overlap, and
- wherein performing the noise coring operation includes adjusting a noise coring strength using a coring width parameter in the first region and the second region.
Dependencies are inferred from the claim text.