Multiresolution based method for removing noise from digital images

In a method of removing noise from a digital image, comprising the steps of:

• a) receiving an original digital image including a plurality of pixels;
• b) generating at least one residual digital image and at least one base digital image from the original digital image using wavelet filters or discrete cosine transform filters, the base digital image having a lower spatial resolution than the original digital image;
• and
• c) generating a noise reduced base digital image by removing noise from the base digital image with a noise reduction filter so that when the noise reduced base digital image is combined with the residual digital image to produce a reconstructed digital image, noise is not present in the reconstructed digital image.

In a method of removing noise from a digital image, comprising the steps of:

• a) receiving an original digital image including a plurality of pixels;
• b) sequentially generating, starting from the original digital image, a plurality of residual digital images and a plurality of corresponding base digital images, respectively, wherein each base digital image has a lower spatial resolution than the previous digital image from which is was derived;
• and
• c) generating noise reduced base digital images by removing noise from at least one of the base digital images with a noise reduction filter so that when the noise reduced base digital images are combined with corresponding residual digital images to produce reconstructed digital images, noise is not present in the reconstructed digital images.

In a method of removing noise from a digital image comprising the steps of:

• a) receiving an original digital image including a plurality of pixels;
• b) noise filtering the original digital image to produce a noise reduced original digital image;
• c) generating at least one residual digital image and at least one base digital image from the noise reduced original digital image, the base digital image having a lower spatial resolution than the noise reduced original digital image;
• and
• d) generating a noise reduced base digital image by removing noise from the base digital image with a noise reduction filter so that when the noise reduced base digital image is combined with the residual digital image producing a reconstructed digital image, noise is not present in the reconstructed digital image.

In a method of removing noise from a digital image comprising the steps of:

• a) receiving an original digital image including a plurality of pixels;
• b) noise filtering the original digital image to produce a noise reduced original digital image;
• c) generating at least one residual digital image and at least one base digital image from the noise reduced original digital image using wavelet filters or discrete cosine transform filters, the base digital image having a lower spatial resolution than the original digital image;
• and
• d) generating a noise reduced base digital image by removing noise from the base digital image with a noise reduction filter so that when the noise reduced base digital image is combined with the residual digital image to produce a reconstructed digital image, noise is not present in the reconstructed digital image.

In a method of removing noise from a digital image comprising the steps of:

• a) receiving an original digital image including a plurality of pixels;
• b) noise filtering the original digital image to produce a noise reduced original digital image;
• c) sequentially generating, starting from the noise reduced original digital image, a plurality of residual digital images and a plurality of corresponding base digital images, respectively, wherein each base digital image has a lower spatial resolution than the previous digital image from which is was derived;
• and
• d) generating noise reduced base digital images by removing noise from at least one base digital image with a noise reduction filter so that when the noise reduced base digital images are combined with corresponding residual digital images to produce reconstructed digital images, noise is not present in the reconstructed digital images.