An image compressing device includes: a histogram creating unit configured to create a histogram regarding an input image; an original type recognizing unit configured to recognize an original type of the input image using the histogram; and an image compressing unit configured to perform a compression process for creating a high-compressed image file from the input image and to control a compression mode of the compression process depending on at least the original type recognized by the original type recognizing unit.

A method using L processers includes: receiving image data encoded by delta row encoding; dividing the two dimensionally arranged plurality of pixels by M (ML) to make M blocks of pixels; assigning M processers to perform a parallel processing of accumulating the delta data for all the row lines of each of the M blocks of the image data to obtain the accumulated delta data, the accumulated delta data including a total delta between the first row line and the last row line in each of the blocks; obtaining the first row lines in the respective blocks using the total delta one by one starting from the second block; and assigning M+1 processers to perform a parallel processing of decoding using the obtained first row lines to obtain the decoded data and a parallel processing of rendering the image data using the decoded data.

An image compressing device includes: a histogram creating unit configured to create a histogram regarding an input image; an original type recognizing unit configured to recognize an original type of the input image using the histogram; and an image compressing unit configured to perform a compression process for creating a high-compressed image file from the input image and to control a compression mode of the compression process depending on at least the original type recognized by the original type recognizing unit.

A method using L processers includes: receiving image data encoded by delta row encoding; dividing the two dimensionally arranged plurality of pixels by M (ML) to make M blocks of pixels; assigning M processers to perform a parallel processing of accumulating the delta data for all the row lines of each of the M blocks of the image data to obtain the accumulated delta data, the accumulated delta data including a total delta between the first row line and the last row line in each of the blocks; obtaining the first row lines in the respective blocks using the total delta one by one starting from the second block; and assigning M+1 processers to perform a parallel processing of decoding using the obtained first row lines to obtain the decoded data and a parallel processing of rendering the image data using the decoded data.

In various examples there is a method for encoding a binary image, the method comprising receiving the binary image; performing run-length encoding on pixel data of the binary image to produce run-length encoded data; performing differential encoding on the run-length encoded data to produce differential encoded data; performing variable length encoding on the differential encoded data to produce variable length encoded data; and applying a lossless compressor to the variable length encoded data to produce compressed data, the compressed data being an encoded binary image.