← Back to Patent Explorer
US6020897A Expired / Lapsed US ⏱️ 0.0 years remaining

Dehalftoning of digital images

Assignee: Adobe Inc
•
Filing: 1997-12-22
•
Granted: 2000-02-01
•
Expires: 2017-12-22
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract Methods and apparatus for blending graphics objects. In one aspect, a method includes receiving a first graphics object; rendering the first graphics object to produce a first pixel map having a first bit depth; increasing a bit depth of a second pixel map associated with a second graphics object that is to be blended with the first graphics object, where the second bit depth is less than the first bit depth; and blending the first and second pixel maps. The method may be implemented to blend graphics objects received by a printing device. In one embodiment, the invention features blending deep pixel data received by a printing device with corresponding shallow halftoned data stored in a shallow frame buffer. The invention may be implemented as a printer configured to receive a page description language description of a page to be printed, the printer including a dehalftone engine for deriving deep pixel data values for objects stored in a shallow frame buffer. In another aspect, the invention features using a pixelmap representative of underlying graphics data for transfer between a host and a remote device by transmitting a halftone representation of the pixelmap from the host to the remote device and reconstructing the pixelmap at the remote device from the halftone representation and a threshold matrix.

Inventors

  • 👤 Stephen E. Carlsen
  • 👤 Lars U. Borg

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 20:21
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/387; G; G06; G06T; G06T11/00; G06T11/60

Claims Analysis

Total Claims: 40
Claim 1
Independent Claim 87 words
A method blending graphics objects comprising: receiving a first graphics object; rendering the first graphics object to produce a first pixel map having a first bit depth; providing a second pixel map associated with a second graphics object that is to be blended with the first graphics object, the second pixel map having a second bit depth, where the second bit depth is less than the first bit depth; increasing the second bit depth of the second pixel map; and blending the first and second pixel maps.
Claim 2
Independent Claim 87 words
A method blending graphics objects comprising: receiving a first graphics object; rendering the first graphics object to produce a first pixel map having a first bit depth; providing a second pixel map associated with a second graphics object that is to be blended with the first graphics object, the second pixel map having a second bit depth, where the second bit depth is less than the first bit depth; increasing the second bit depth of the second pixel map; and blending the first and second pixel maps.
Claim 3
Dependent Claim 22 words
The method of claim 1 wherein the step of increasing the bit depth includes dehalftoning data associated with the second pixel map.
Claim 4
Dependent Claim 76 words
The method of claim 2 wherein the step of dehalftoning includes computing a dehalftone region size for the second pixel map; dividing the second pixel map into regions according to the dehalftone region size; checking each region for flatness and for each region that is not flat, subdividing the region until each resulting sub-region is flat; and for each region and sub-region, calculating a singular deep pixel data value representative of a shade in that region.
Claim 5
Dependent Claim 27 words
The method of claim 3 further including the steps of grouping sub-regions according to shading and adjacency and calculating a shade for all sub-regions within a group.
Claim 6
Dependent Claim 13 words
The method of claim 1 wherein the blending step produces a transparency effect.
Claim 7
Dependent Claim 13 words
The method of claim 1 wherein the blending step produces an overprinting effect.
Claim 8
Dependent Claim 13 words
The method of claim 1 wherein the blending step produces a darkening effect.
Claim 9
Dependent Claim 13 words
The method of claim 1 wherein the blending step produces a lightening effect.
Claim 10
Dependent Claim 13 words
The method of claim 1 wherein the blending step produces a shadow effect.
Claim 11
Dependent Claim 13 words
The method of claim 1 wherein the blending step produces a screen effect.
Claim 12
Dependent Claim 13 words
The method of claim 1 wherein the blending step produces an additive effect.
Claim 13
Dependent Claim 34 words
The method of claim 1 wherein the second pixel map includes halftone data, and where the increasing step generates deep pixel data from halftone data in the second pixel map using a threshold matrix.
Claim 14
Dependent Claim 35 words
The method of claim 1 wherein the second pixel map is stored in a frame buffer prior to increasing the bit depth and the frame buffer is at least two bits deep per color component.
Claim 15
Dependent Claim 33 words
The method of claim 1 wherein the second pixel map is stored in a frame buffer prior to increasing the bit depth and the frame buffer is one bit deep per color component.
Claim 16
Independent Claim 86 words
A method blending graphics objects received by a printing device comprising: rendering a first graphics object to produce a first pixel map having a first bit depth; restoring a bit depth of a second pixel map associated with a second graphics object that is to be blended with the first graphics object to the first bit depth, where the second pixel map was previously rendered at a second bit depth that was less than the first bit depth; and blending the first and second pixel maps.
Claim 17
Independent Claim 86 words
A method blending graphics objects received by a printing device comprising: rendering a first graphics object to produce a first pixel map having a first bit depth; restoring a bit depth of a second pixel map associated with a second graphics object that is to be blended with the first graphics object to the first bit depth, where the second pixel map was previously rendered at a second bit depth that was less than the first bit depth; and blending the first and second pixel maps.
Claim 18
Independent Claim 102 words
A method blending graphics objects received by a printing device comprising: receiving a first graphics object; rendering the first graphics object to produce a first pixel map having a first bit depth; reducing the bit depth of the first pixel map; storing the first pixel map; receiving a second graphics object to be blended with the first graphics object; rendering the second graphics object to produce a second pixel map, the second pixel map including data at a blend bit depth; increasing the bit depth of the first pixel map to the blend bit depth; blending the first and second pixel maps.
Claim 19
Independent Claim 102 words
A method blending graphics objects received by a printing device comprising: receiving a first graphics object; rendering the first graphics object to produce a first pixel map having a first bit depth; reducing the bit depth of the first pixel map; storing the first pixel map; receiving a second graphics object to be blended with the first graphics object; rendering the second graphics object to produce a second pixel map, the second pixel map including data at a blend bit depth; increasing the bit depth of the first pixel map to the blend bit depth; blending the first and second pixel maps.
Claim 20
Independent Claim 85 words
A method blending deep pixel data received by a printing device with corresponding shallow data stored in a shallow frame buffer, the method comprising: receiving deep pixel data associated with a first graphics object; restoring deep pixel data values from shallow pixel data stored in the shallow frame buffer associated with a second graphics object previously rendered into the shallow frame buffer; and blending the deep pixel data associated with the first graphics object and restored deep pixel data associated with the second graphics object.
Claim 21
Independent Claim 85 words
A method blending deep pixel data received by a printing device with corresponding shallow data stored in a shallow frame buffer, the method comprising: receiving deep pixel data associated with a first graphics object; restoring deep pixel data values from shallow pixel data stored in the shallow frame buffer associated with a second graphics object previously rendered into the shallow frame buffer; and blending the deep pixel data associated with the first graphics object and restored deep pixel data associated with the second graphics object.
Claim 22
Dependent Claim 145 words
A printer configured to receive a page description language description of a page to be printed, comprising: a render engine for rendering received page description objects for the page into deep pixel data; a halftone engine operating on deep pixel data to create halftone data representative of the objects; a shallow frame buffer for storing halftone data; a dehalftone engine for approximating deep pixel data values for objects stored in the shallow frame buffer resulting in restored deep pixel data; a blending engine for blending rendered deep pixel data and restored deep pixel data resulting in blended data, the blended data operated on by the halftone engine to derive halftone data for storage in the shallow frame buffer; and a print engine for printing halftone data from the shallow frame buffer resulting in a blending of image data according to a user defined blending function.
Claim 23
Dependent Claim 145 words
A printer configured to receive a page description language description of a page to be printed, comprising: a render engine for rendering received page description objects for the page into deep pixel data; a halftone engine operating on deep pixel data to create halftone data representative of the objects; a shallow frame buffer for storing halftone data; a dehalftone engine for approximating deep pixel data values for objects stored in the shallow frame buffer resulting in restored deep pixel data; a blending engine for blending rendered deep pixel data and restored deep pixel data resulting in blended data, the blended data operated on by the halftone engine to derive halftone data for storage in the shallow frame buffer; and a print engine for printing halftone data from the shallow frame buffer resulting in a blending of image data according to a user defined blending function.
Claim 24
Independent Claim 68 words
A method of deriving deep pixel data from halftone data comprising: computing a dehalftone region size; dividing the halftone data into regions according to the dehalftone region size; checking each region for flatness, and further sub-dividing each region that is not flat until each resulting sub-region is flat; and for each region and sub-region calculating a singular deep pixel data value representative of a shade in that region.
Claim 25
Independent Claim 68 words
A method of deriving deep pixel data from halftone data comprising: computing a dehalftone region size; dividing the halftone data into regions according to the dehalftone region size; checking each region for flatness, and further sub-dividing each region that is not flat until each resulting sub-region is flat; and for each region and sub-region calculating a singular deep pixel data value representative of a shade in that region.
Claim 26
Dependent Claim 27 words
The method of claim 19 further including the steps of grouping sub-regions according to shading and adjacency and calculating a shade for all sub-regions within a group.
Claim 27
Independent Claim 49 words
A method of transmitting graphics data between a host and a remote device comprising: transmitting a halftone representation of a pixelmap from the host to the remote device; reconstructing the pixelmap at the remote device from the halftone representation and a threshold matrix used to construct the halftone representation.
Claim 28
Independent Claim 49 words
A method of transmitting graphics data between a host and a remote device comprising: transmitting a halftone representation of a pixelmap from the host to the remote device; reconstructing the pixelmap at the remote device from the halftone representation and a threshold matrix used to construct the halftone representation.
Claim 29
Dependent Claim 14 words
The method of claim 21 wherein the reconstructing step includes dehalftoning the halftone representation.
Claim 30
Dependent Claim 20 words
The method of claim 21 further including using a reconstructed pixel map in a trapping operation in the remote device.
Claim 31
Dependent Claim 20 words
The method of claim 21 further including using a reconstructed pixel map in a blending operation in the remote device.
Claim 32
Dependent Claim 21 words
The method of claim 21 further including using a reconstructed pixel map in a color adjustment operation in the remote device.
Claim 33
Dependent Claim 16 words
The method of claim 21 further including re-halftoning a reconstructed pixelmap based on new halftone parameters.
Claim 34
Independent Claim 61 words
A method of transmitting a pixelmap representative of underlying graphics data for transfer between a host and a remote device, the pixelmap having a first bit depth, the method comprising: reducing the bit depth of the pixelmap; transmitting a reduced bit depth representation of the pixelmap from the host to the remote device; and reconstructing the pixelmap at the remote device.
Claim 35
Independent Claim 61 words
A method of transmitting a pixelmap representative of underlying graphics data for transfer between a host and a remote device, the pixelmap having a first bit depth, the method comprising: reducing the bit depth of the pixelmap; transmitting a reduced bit depth representation of the pixelmap from the host to the remote device; and reconstructing the pixelmap at the remote device.
Claim 36
Dependent Claim 13 words
The method of claim 27 wherein the reducing step includes halftoning the pixelmap.
Claim 37
Dependent Claim 16 words
The method of claim 28 wherein the reconstructing step includes dehalftoning the reduced bit depth representation.
Claim 38
Dependent Claim 25 words
The method of claim 27 wherein lossless compression is applied to the reduced bit depth representation before the representation is transmitted to the remote device.
Claim 39
Independent Claim 64 words
A method of increasing the bit depth of a reduced bit depth pixelmap of the form of halftone data representative of an underlying image, comprising: generating a pixelmap from the halftone data and a threshold matrix used to construct the halftone data by grouping regions of halftone data according to shading and adjacency and calculating a single shade for all regions within a group.
Claim 40
Independent Claim 64 words
A method of increasing the bit depth of a reduced bit depth pixelmap of the form of halftone data representative of an underlying image, comprising: generating a pixelmap from the halftone data and a threshold matrix used to construct the halftone data by grouping regions of halftone data according to shading and adjacency and calculating a single shade for all regions within a group.

References Cited (Backward Citations)

US4977458A Cited
US5235435A Cited
US5285291A Cited
US5305118A Cited
US5124803A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2003-01-31 2003-08-02 2004-02-01 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2007-01-31 2007-08-02 2008-02-01 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2011-01-31 2011-08-02 2012-02-01 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag