Wavelet transformation-based image encoder, decoder and method for generating thumbnail image

A method for generating a thumbnail image from the original image comprising the steps of:

• dividing the original image by an image tiling unit into a predetermined number of images;
• determining a number of wavelet transformations by a wavelet transformation unit for each of the divided images;
• performing wavelet transformation by the wavelet transformation unit for each of the divided images according to the determined number of wavelet transformations and outputting the wavelet transformed data;
• extracting by an extractor unit only specific wavelet transformed data for each of the divided images, wherein the specific wavelet transformed data is data filtered by at least one filter of filters in a wavelet transformation unit;
• range mapping by an image processor for a color value of each pixel included in each of the specific extracted wavelet transformed data;
• and
• generating a thumbnail image corresponding to an entirety of the original image by assembling each of the range-mapped, wavelet transformed data.

A wavelet transformation based-image decoder apparatus including machine executable code on a non-transitory machine readable medium, the decoder apparatus comprising:

• an entropy decoding processing unit for entropy decoding of an image encoded according to a wavelet transformation method;
• a bit stream parsing processing unit for parsing a bit stream of the entropy decoded wavelet encoded image output by the entropy decoding unit;
• an LL image extractor processing unit for receiving the result of the bit stream parsing of the wavelet encoded image and extracting low-low image data from the result;
• and
• a range mapping processing unit including processing means for performing range mapping for the color value of pixels included in each of the extracted LL image data and outputting the LL image data as a thumbnail image for the wavelet encoded image.

A method for decoding of an encoded image according to a wavelet transformation method of an original image, said method including the steps of:

• entropy decoding by an entropy decoding processing unit for performing the entropy decoding of the encoded image according to the wavelet transformation scheme;
• parsing by a bit stream parsing processing unit the bit stream of the entropy decoded wavelet encoded image;
• receiving by an LL image extraction processing unit the result of the bit stream parsing of the wavelet encoded image and extracting low-low (LL) image data from the result;
• range mapping by a range mapping processing unit for a color value of pixels included in each of the extracted LL image data;
• and
• outputting by the range mapping processing unit the LL image data of which the range mapping has been completed as a thumbnail image for an entirety of the wavelet encoded image.