Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
149 words
A printer driver for a printer; said printer driver managing a two layer buffer which represents a page to be printed; the first layer of said buffer containing background contone data; the second layer of said buffer containing foreground bi-level data; said printer driver transmitting data from said buffer to said printer; said printer compositing data from said layers of said buffer; said printer driver operating such that when it determines that contone data being composited with said contone layer obscures data in said bi-level layer, said obscured bi-level data is removed from said bi-level layer and is either discarded, or in the case where there is some interaction between the image represented by said obscuring contone data and the image represented by said obscured bi-level data then said obscured bi-level data is composited with said contone layer before said obscuring contone data is composited with said contone layer.
Claim 2
Dependent Claim
149 words
A printer driver for a printer; said printer driver managing a two layer buffer which represents a page to be printed; the first layer of said buffer containing background contone data; the second layer of said buffer containing foreground bi-level data; said printer driver transmitting data from said buffer to said printer; said printer compositing data from said layers of said buffer; said printer driver operating such that when it determines that contone data being composited with said contone layer obscures data in said bi-level layer, said obscured bi-level data is removed from said bi-level layer and is either discarded, or in the case where there is some interaction between the image represented by said obscuring contone data and the image represented by said obscured bi-level data then said obscured bi-level data is composited with said contone layer before said obscuring contone data is composited with said contone layer.
Claim 3
Dependent Claim
35 words
A printer driver according to claim 1 , where said interaction occurs between an image represented by said obscuring contone data and said obscured bi-level data when said contone data represents a non-opaque image object.
Claim 4
Dependent Claim
24 words
A printer driver according to claim 1 , where said contone layer data is color data, and said bi-level layer data is black data.
Claim 5
Dependent Claim
141 words
A printer driver according to claim 3 , where the following rules are implemented by said printer driver: when a black image object is composited with said page buffer, it is composited with said bi-level black layer; when a contone color image object is composited with said page buffer, it is composited with said contone color layer; wherever said contone image object obscures said black layer, even if not fully opaquely, obscured black layer pixels are composited with said contone layer, and removed from said black layer, before said contone object is composited with said contone layer; if a pixel of said contone object is fully opaque, then there is no need to composite corresponding pixels in said black layer with said contone layer, since the corresponding pixel in said contone layer will be completely replaced by said contone object pixel.
Claim 6
Dependent Claim
20 words
A printer driver according to claim 1 , where said contone layer has a lower resolution than said bi-level layer.
Claim 7
Dependent Claim
158 words
A printer driver according to claim 5 , where said two layer page buffer is augmented with a third layer of contone data; said third layer containing a contone version of the bi-level data of said second layer subsampled at the resolution of said first layer; said printer driver operating such that when it determines that contone data being composited with said first layer obscures contone data in said third layer, said obscured contone data is removed from said third layer and is either discarded, or in the case where there is some interaction between the image represented by said obscuring contone data and the image represented by said obscured contone data then said obscured contone data is composited with said first layer before said obscuring contone data is composited with said first layer, and bi-level data in said second layer which corresponds to said obscured contone data in said third layer is removed from said second layer.
Claim 8
Dependent Claim
21 words
A printer driver according to claim 5 , where said bi-level layer data is transmitted to said printer in compressed form.
Claim 9
Dependent Claim
37 words
A printer driver according to claim 7 , where Group 4 facsimile coding is used for said bi-level compression, with the modified Huffman coding of horizontal run lengths removed, tuned for higher resolutions, or used as normal.
Claim 10
Dependent Claim
17 words
A printer driver according to claim 7 , where EDRL compression is used for said bi-level compression.
Claim 11
Dependent Claim
21 words
A printer driver according to claim 5 , where said contone layer data is transmitted to said printer in compressed form.
Claim 12
Dependent Claim
20 words
A printer driver according to claim 10 , where JPEG compression or wavelet compression is used for said contone compression.
Claim 13
Dependent Claim
151 words
In a printer driver for a printer; said printer driver managing a two layer buffer which represents a page to be printed; the first layer of said buffer containing background contone data; the second layer of said buffer containing foreground bi-level data; said printer driver transmitting data from said buffer to said printer; said printer compositing data from said layers of said buffer; a method comprising the following steps: operating said printer driver to determine whether contone data being composited with said contone layer obscures data in said bi-level layer; removing said obscured bi-level data from said bi-level layer; and either discarding said obscured bi-level data, or in the case where there is some interaction between the image represented by said obscuring contone data and the image represented by said obscured bi-level data, compositing said obscured bi-level data with said contone layer before compositing said obscuring contone data-with said contone layer.
Claim 14
Dependent Claim
151 words
In a printer driver for a printer; said printer driver managing a two layer buffer which represents a page to be printed; the first layer of said buffer containing background contone data; the second layer of said buffer containing foreground bi-level data; said printer driver transmitting data from said buffer to said printer; said printer compositing data from said layers of said buffer; a method comprising the following steps: operating said printer driver to determine whether contone data being composited with said contone layer obscures data in said bi-level layer; removing said obscured bi-level data from said bi-level layer; and either discarding said obscured bi-level data, or in the case where there is some interaction between the image represented by said obscuring contone data and the image represented by said obscured bi-level data, compositing said obscured bi-level data with said contone layer before compositing said obscuring contone data-with said contone layer.
Claim 15
Dependent Claim
34 words
A method according to claim 12 , where said interaction occurs between an image represented by said obscuring contone data and said obscured bi-level data where said contone data represents a non-opaque image object.
Claim 16
Dependent Claim
19 words
A method according to claim 12 , where said contone layer has a lower resolution than said bi-level layer.
Claim 17
Dependent Claim
153 words
A method according to claim 14 , where said two layer page buffer is augmented with a third layer of contone data; said third layer containing a contone version of the bi-level data of said second layer subsampled at the resolution of said first layer; said method comprising the following steps: operating said printer driver to determine whether contone data being composited with said first layer obscures data in said third layer; removing said obscured contone data from said third layer; either discarding said obscured contone data, or in the case where there is some interaction between the image represented by said obscuring contone data and the image represented by said obscured contone data then compositing said obscured contone data with said first layer before compositing said obscuring contone data with said first layer; and removing from said second layer bi-level data which corresponds to said obscured contone data in said third layer.
Claim 18
Dependent Claim
23 words
A method according to claim 12 , where said contone layer data is color data, and said bi-level layer data is black data.
Claim 19
Dependent Claim
140 words
A method according to claim 16 , where the following rules are implemented by said printer driver: when a black image object is composited with said page buffer, it is composited with said bi-level black layer; when a contone color image object is composited with said page buffer, it is composited with said contone color layer; wherever said contone image object obscures said black layer, even if not fully opaquely, obscured black layer pixels are composited with said contone layer, and removed from said black layer, before said contone object is composited with said contone layer; if a pixel of said contone object is fully opaque, then there is no need to composite corresponding pixels in said black layer with said contone layer, since the corresponding pixel in said contone layer will be completely replaced by said contone object pixel.