Patent Application
20100254597
The subject application is directed generally to improving quality of digitally encoded color images. The application is particularly applicable to isolation or detection of facial areas in image data and improving the color characteristics thereof.
More recently, images are acquired as encoded, digital image data. Such image data is obtained via devices such as digital cameras, both for still images and moving pictures. Digital image data is also acquired by scanning of tangible images, such as from pictures or negatives obtained via more traditional, film-based cameras. Color image data is typically encoded in a multidimensional color space, such as red-green-blue (RGB); cyan-magenta-yellow (CMY), which may include black (CMYK); or any other of a plurality of alternative encoding schemes.
A large number of images include depictions of human faces, which frequently form the area or areas of greatest interest to a viewer. It is desirable to have as accurate a depiction of facial images as possible. Earlier systems, operable on a black-and-white rendering of a digital image, sought to isolate a facial region for special treatment. However, such systems are prone to false positives, and are generally separated from any system that seeks to perform image correction.
In accordance with one embodiment of the subject application, there is provided a system and method for facial tone indexing. Image data comprised of a plurality of pixels encoded in at least a three dimensional component space is received and at least one candidate facial region is isolated in the received image data. The received image data is translated to Lightness, Chroma, Hue (LCH) color space. Histogram data corresponding to the Hue of pixels is calculated in the at least one candidate facial region by discarding the low-Chroma pixels first. The Hue index on which the Hue histogram peaks is identified as the Facial Tone index. The Facial Tone Index indicates where the Hue concentration is and therefore is a single number representing the flesh tone of a face.
Still other advantages, aspects and features of the subject application will become readily apparent to those skilled in the art from the following description wherein there is shown and described a preferred embodiment of the subject application, simply by way of illustration of one of the best modes best suited to carry out the subject application. As it will be realized, the subject application is capable of other different embodiments and its several details are capable of modifications in various obvious aspects all without departing from the scope of the subject application. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawings will be provided by the Office upon request and payment of the necessary fee.
The subject application is described with reference to certain figures, including:
The subject application is directed to a system and method for improving quality of digitally encoded color images. In particular, the subject application is directed to a system and method for isolation or detection of facial areas in image data and improving the color characteristics thereof. More particularly, the subject application is directed to a system and method for facial tone indexing. It will become apparent to those skilled in the art that the system and method described herein are suitably adapted to a plurality of varying electronic fields employing image processing, including, for example and without limitation, communications, general computing, data processing, document processing, financial transactions, vending of products or services, or the like. The preferred embodiment, as depicted in
Referring now to
The skilled artisan will appreciate that while a computer network 102 is shown in
The system 100 also includes a document processing device 104, which is depicted in
According to one embodiment of the subject application, the document processing device 104 is suitably equipped to receive a plurality of portable storage media, including, without limitation, Firewire drive, USB drive, SD, MMC, XD, Compact Flash, Memory Stick, and the like. In the preferred embodiment of the subject application, the document processing device 104 further includes an associated user interface 106, such as a touchscreen, LCD display, touch-panel, alpha-numeric keypad, or the like, via which an associated user is able to interact directly with the document processing device 104. In accordance with the preferred embodiment of the subject application, the user interface 106 is advantageously used to communicate information to the associated user and receive selections from the associated user. The skilled artisan will appreciate that the user interface 106 comprises various components, suitably adapted to present data to the associated user, as are known in the art. In accordance with one embodiment of the subject application, the user interface 106 comprises a display, suitably adapted to display one or more graphical elements, text data, images, or the like, to an associated user, receive input from the associated user, and communicate the same to a backend component, such as the controller 108, as explained in greater detail below. Preferably, the document processing device 104 is communicatively coupled to the computer network 102 via a communications link 112. As will be understood by those skilled in the art, suitable communications links include, for example and without limitation, WiMax, 802.11a, 802.11b, 802.11g, 802.11(x), Bluetooth, the public switched telephone network, a proprietary communications network, infrared, optical, or any other suitable wired or wireless data transmission communications known in the art. The functioning of the document processing device 104 will be better understood in conjunction with the block diagrams illustrated in
In accordance with one embodiment of the subject application, the document processing device 104 incorporates a backend component, designated as the controller 108, suitably adapted to facilitate the operations of the document processing device 104, as will be understood by those skilled in the art. Preferably, the controller 108 is embodied as hardware, software, or any suitable combination thereof, configured to control the operations of the associated document processing device 104, facilitate the display of images via the user interface 106, direct the manipulation of electronic image data, perform color image processing, and the like. For purposes of explanation, the controller 108 is used to refer to any myriad of components associated with the document processing device 104, including hardware, software, or combinations thereof, functioning to perform, cause to be performed, control, or otherwise direct the methodologies described hereinafter. It will be understood by those skilled in the art that the methodologies described with respect to the controller 108 is capable of being performed by any general purpose computing system, known in the art, and thus the controller 108 is representative of such general computing devices and is intended as such when used hereinafter. Furthermore, the use of the controller 108 hereinafter is for the example embodiment only, and other embodiments, which will be apparent to one skilled in the art, are capable of employing the facial tone indexing system and method. The functioning of the controller 108 will better be understood in conjunction with the block diagrams illustrated in
Communicatively coupled to the document processing device 104 is a data storage device 110. In accordance with the one embodiment of the subject application, the data storage device 110 is any mass storage device known in the art including, for example and without limitation, magnetic storage drives, a hard disk drive, optical storage devices, flash memory devices, or any suitable combination thereof. In one embodiment, the data storage device 110 is suitably adapted to store scanned image data, modified image data, photographic data, color processing data, or the like. It will be appreciated by those skilled in the art that while illustrated in
The system 100 of
The system 100 illustrated in
Communicatively coupled to the server 124 is the data storage device 126. According to the foregoing example embodiment, the data storage device 126 is any mass storage device, or plurality of such devices, known in the art including, for example and without limitation, magnetic storage drives, a hard disk drive, optical storage devices, flash memory devices, or any suitable combination thereof. In such an embodiment, the data storage device 126 is suitably adapted to store color imaging data, color images, photographs, documents, and the like. It will be appreciated by those skilled in the art that while illustrated in
Also depicted in
The communications link 134 is any suitable channel of data communications known in the art including, but not limited to wireless communications, for example and without limitation, Bluetooth, WiMax, 802.11a, 802.11b, 802.11g, 802.11(x), a proprietary communications network, infrared, optical, the public switched telephone network, or any suitable wireless data transmission system, or wired communications known in the art. Preferably, the computer workstation 134 is suitably configured to perform image processing, color image modification, imaging calculations, generate output data, or the like, with respect to the document processing device 104, or any other similar device coupled to the computer network 102. The functioning of the computer workstation 134 will better be understood in conjunction with the block diagram illustrated in
Additionally, the system 100 of
Turning now to
Also included in the device 200 is random access memory 206, suitably formed of dynamic random access memory, static random access memory, or any other suitable, addressable memory system. Random access memory provides a storage area for data instructions associated with applications and data handling accomplished by the processor 202.
A storage interface 208 suitably provides a mechanism for volatile, bulk or long term storage of data associated with the device 200. The storage interface 208 suitably uses bulk storage, such as any suitable addressable or serial storage, such as a disk, optical, tape drive and the like as shown as 216, as well as any suitable storage medium as will be appreciated by one of ordinary skill in the art.
A network interface subsystem 210 suitably routes input and output from an associated network allowing the device 200 to communicate to other devices. The network interface subsystem 210 suitably interfaces with one or more connections with external devices to the device 200. By way of example, illustrated is at least one network interface card 214 for data communication with fixed or wired networks, such as Ethernet, token ring, and the like, and a wireless interface 218, suitably adapted for wireless communication via means such as WiFi, WiMax, wireless modem, cellular network, or any suitable wireless communication system. It is to be appreciated however, that the network interface subsystem suitably utilizes any physical or non-physical data transfer layer or protocol layer as will be appreciated by one of ordinary skill in the art. In the illustration, the network interface card 214 is interconnected for data interchange via a physical network 220, suitably comprised of a local area network, wide area network, or a combination thereof.
Data communication between the processor 202, read only memory 204, random access memory 206, storage interface 208 and the network subsystem 210 is suitably accomplished via a bus data transfer mechanism, such as illustrated by the bus 212.
Suitable executable instructions on the device 200 facilitate communication with a plurality of external devices, such as workstations, document processing devices, other servers, or the like. While, in operation, a typical device operates autonomously, it is to be appreciated that direct control by a local user is sometimes desirable, and is suitably accomplished via an optional input/output interface 222 to a user input/output panel 224 as will be appreciated by one of ordinary skill in the art.
Also in data communication with the bus 212 are interfaces to one or more document processing engines. In the illustrated embodiment, printer interface 226, copier interface 228, scanner interface 230, and facsimile interface 232 facilitate communication with printer engine 234, copier engine 236, scanner engine 238, and facsimile engine 240, respectively. It is to be appreciated that the device 200 suitably accomplishes one or more document processing functions. Systems accomplishing more than one document processing operation are commonly referred to as multifunction peripherals or multifunction devices.
Turning now to
The document processing engine 302 suitably includes a print engine 304, facsimile engine 306, scanner engine 308 and console panel 310. The print engine 304 allows for output of physical documents representative of an electronic document communicated to the processing device 300. The facsimile engine 306 suitably communicates to or from external facsimile devices via a device, such as a fax modem.
The scanner engine 308 suitably functions to receive hard copy documents and in turn image data corresponding thereto. A suitable user interface, such as the console panel 310, suitably allows for input of instructions and display of information to an associated user. It will be appreciated that the scanner engine 308 is suitably used in connection with input of tangible documents into electronic form in bitmapped, vector, or page description language format, and is also suitably configured for optical character recognition. Tangible document scanning also suitably functions to facilitate facsimile output thereof.
In the illustration of
The document processing engine 302 is suitably in data communication with one or more device drivers 314, which device drivers allow for data interchange from the document processing engine 302 to one or more physical devices to accomplish the actual document processing operations. Such document processing operations include one or more of printing via driver 318, facsimile communication via driver 320, scanning via driver 322 and a user interface functions via driver 324. It will be appreciated that these various devices are integrated with one or more corresponding engines associated with the document processing engine 302. It is to be appreciated that any set or subset of document processing operations are contemplated herein. Document processors which include a plurality of available document processing options are referred to as multi-function peripherals.
Turning now to
Also included in the controller 400 is random access memory 406, suitably formed of dynamic random access memory, static random access memory, or any other suitable, addressable and writable memory system. Random access memory provides a storage area for data instructions associated with applications and data handling accomplished by processor 402.
A storage interface 408 suitably provides a mechanism for non-volatile, bulk or long term storage of data associated with the controller 400. The storage interface 408 suitably uses bulk storage, such as any suitable addressable or serial storage, such as a disk, optical, tape drive and the like as shown as 416, as well as any suitable storage medium as will be appreciated by one of ordinary skill in the art.
A network interface subsystem 410 suitably routes input and output from an associated network allowing the controller 400 to communicate to other devices. The network interface subsystem 410 suitably interfaces with one or more connections with external devices to the device 400. By way of example, illustrated is at least one network interface card 414 for data communication with fixed or wired networks, such as Ethernet, token ring, and the like, and a wireless interface 418, suitably adapted for wireless communication via means such as WiFi, WiMax, wireless modem, cellular network, or any suitable wireless communication system. It is to be appreciated however, that the network interface subsystem suitably utilizes any physical or non-physical data transfer layer or protocol layer as will be appreciated by one of ordinary skill in the art. In the illustration, the network interface 414 is interconnected for data interchange via a physical network 420, suitably comprised of a local area network, wide area network, or a combination thereof.
Data communication between the processor 402, read only memory 404, random access memory 406, storage interface 408 and the network interface subsystem 410 is suitably accomplished via a bus data transfer mechanism, such as illustrated by bus 412.
Also in data communication with the bus 412 is a document processor interface 422. The document processor interface 422 suitably provides connection with hardware 432 to perform one or more document processing operations. Such operations include copying accomplished via copy hardware 424, scanning accomplished via scan hardware 426, printing accomplished via print hardware 428, and facsimile communication accomplished via facsimile hardware 430. It is to be appreciated that the controller 400 suitably operates any or all of the aforementioned document processing operations. Systems accomplishing more than one document processing operation are commonly referred to as multifunction peripherals or multifunction devices.
Functionality of the subject system 100 is accomplished on a suitable document processing device, such as the document processing device 104, which includes the controller 400 of
In the preferred embodiment, the engine 502 allows for printing operations, copy operations, facsimile operations and scanning operations. This functionality is frequently associated with multi-function peripherals, which have become a document processing peripheral of choice in the industry. It will be appreciated, however, that the subject controller does not have to have all such capabilities. Controllers are also advantageously employed in dedicated or more limited purposes document processing devices that perform one or more of the document processing operations listed above.
The engine 502 is suitably interfaced to a user interface panel 510, which panel allows for a user or administrator to access functionality controlled by the engine 502. Access is suitably enabled via an interface local to the controller, or remotely via a remote thin or thick client.
The engine 502 is in data communication with the print function 504, facsimile function 506, and scan function 508. These functions facilitate the actual operation of printing, facsimile transmission and reception, and document scanning for use in securing document images for copying or generating electronic versions.
A job queue 512 is suitably in data communication with the print function 504, facsimile function 506, and scan function 508. It will be appreciated that various image forms, such as bit map, page description language or vector format, and the like, are suitably relayed from the scan function 308 for subsequent handling via the job queue 512.
The job queue 512 is also in data communication with network services 514. In a preferred embodiment, job control, status data, or electronic document data is exchanged between the job queue 512 and the network services 514. Thus, suitable interface is provided for network based access to the controller function 500 via client side network services 520, which is any suitable thin or thick client. In the preferred embodiment, the web services access is suitably accomplished via a hypertext transfer protocol, file transfer protocol, uniform data diagram protocol, or any other suitable exchange mechanism. The network services 514 also advantageously supplies data interchange with client side services 520 for communication via FTP, electronic mail, TELNET, or the like. Thus, the controller function 500 facilitates output or receipt of electronic document and user information via various network access mechanisms.
The job queue 512 is also advantageously placed in data communication with an image processor 516. The image processor 516 is suitably a raster image process, page description language interpreter or any suitable mechanism for interchange of an electronic document to a format better suited for interchange with device functions such as print 504, facsimile 506 or scan 508.
Finally, the job queue 512 is in data communication with a parser 518, which parser suitably functions to receive print job language files from an external device, such as client device services 522. The client device services 522 suitably include printing, facsimile transmission, or other suitable input of an electronic document for which handling by the controller function 500 is advantageous. The parser 518 functions to interpret a received electronic document file and relay it to the job queue 512 for handling in connection with the afore-described functionality and components.
Turning now to
The read only memory 604 suitably includes firmware, such as static data or fixed instructions, such as BIOS, system functions, configuration data, and other routines used for operation of the workstation 600 via CPU 602.
The random access memory 606 provides a storage area for data and instructions associated with applications and data handling accomplished by the processor 602.
The display interface 608 receives data or instructions from other components on the bus 614, which data is specific to generating a display to facilitate a user interface. The display interface 608 suitably provides output to a display terminal 628, suitably a video display device such as a monitor, LCD, plasma, or any other suitable visual output device as will be appreciated by one of ordinary skill in the art.
The storage interface 610 suitably provides a mechanism for non-volatile, bulk or long term storage of data or instructions in the workstation 600. The storage interface 610 suitably uses a storage mechanism, such as storage 618, suitably comprised of a disk, tape, CD, DVD, or other relatively higher capacity addressable or serial storage medium.
The network interface 612 suitably communicates to at least one other network interface, shown as network interface 620, such as a network interface card, and wireless network interface 630, such as a WiFi wireless network card. It will be appreciated that by one of ordinary skill in the art that a suitable network interface is comprised of both physical and protocol layers and is suitably any wired system, such as Ethernet, token ring, or any other wide area or local area network communication system, or wireless system, such as WiFi, WiMax, or any other suitable wireless network system, as will be appreciated by one of ordinary skill in the art. In the illustration, the network interface 620 is interconnected for data interchange via a physical network 632, suitably comprised of a local area network, wide area network, or a combination thereof.
An input/output interface 616 in data communication with the bus 614 is suitably connected with an input device 622, such as a keyboard or the like. The input/output interface 616 also suitably provides data output to a peripheral interface 624, such as a USB, universal serial bus output, SCSI, Firewire (IEEE 1394) output, or any other interface as may be appropriate for a selected application. Finally, the input/output interface 616 is suitably in data communication with a pointing device interface 626 for connection with devices, such as a mouse, light pen, touch screen, or the like.
Turning now to
Referring now to
The skilled artisan will appreciate that the subject system 100 and components described above with respect to
At step 904, at least one candidate facial region is isolated in the received image data. Those skilled in the art will appreciate that the controller 108 or other suitable component associated with the document processing device 104, the workstation 130, or other suitable device (not shown), is capable of performing the isolation of the possible facial region in accordance with the subject application. Histogram data is then calculated at step 906 corresponding to a Hue of pixels in the at least one candidate facial region. Examples of such histograms are discussed in greater detail below with respect to
Referring now to
At step 1004, the received input image data is analyzed so as to determine whether the image is a monochromatic or sepia image.
Following isolation of a candidate region, the controller 108 or other suitable component associated with the document processing device 104, or the workstation 130, converts the received image data into a Lightness, Chroma, Hue color space at step 1008. More specifically, the Red, Green Blue (RGB) color space is capable of being translated into a CIE tri-stimulus X, Y, Z system which in turn is translatable into L*a*b* color space in which L* represents Lightness. In the three-dimensional color space L*a*b*, on each constant L* plane, the two-dimensional coordinate (a*, b*) represents color information, e.g. the L* axis is also referenced as the “neutral axis” where a*=0 and b*=0; the Euclidean distance from each point (a*, b*) to the neutral axis ((a*)+(b*)) is the Chroma C*; and the angle arctan(b*/a*) is the Hue H*. It will be appreciated by those skilled in the art that suitable Lightness, Chroma, and Hue color spaces includes, for example and without limitation, CIE L*C*H*, and the like, the use of any of which is capable of implementation in accordance with the subject application. In accordance with one embodiment of the subject application, a Facial Tone Index is representative of an index between 0 and 100 representing the scaled 360 degrees of the Hue angle in Lightness, Chroma, and Hue color space.
It will be appreciated by those skilled in the art that there is some Hue concentration in flesh tone colors within the facial region of a human subject. Accordingly, via the isolation, i.e. cropping, of a candidate facial region, the corresponding Hue histogram is capable of including a spike or peak value. In accordance with one embodiment of the subject application, the Hue value indicated at the peak of the Hue histogram is referenced as a Facial Tone Index. It will be understood by those skilled in the art that Facial Tone Index is one of a plurality of color attributes that are capable of being leveraged so as to predict if an input image requires image quality improvement. The skilled artisan will appreciate that as a natural color attribute, the Facial Tone Index is not derived from a monochrome or a sepia image (i.e.
Therefore, at step 1010, a determination is made by the controller 108 or workstation 130 of a number of pixels (P) in the isolated candidate region that have a Chroma value within a ranged defined by a preselected threshold value (Th). Following the determination of P, a determination is made at step 1012 whether the value P (number of pixels having a chroma value less than the Th value) is greater than a predetermined threshold value (Th′). That is, whether the isolated candidate facial region includes a high percentage of low-chroma pixels.
Upon a determination at step 1012 that the value P is less than the predetermined threshold value Th′, flow proceeds to step 1014. At step 1014, normalized histogram data is calculated of the candidate facial region based upon a Hue of pixels in the region. That is, the Hue plane of the isolated region is extracted and the low-chroma pixels (chroma<Th) are discarded, whereupon a normalized histogram is calculated therefrom. At step 1016, a maximum is calculated from the normalized Hue histogram. It will be appreciated by those skilled in the art that such calculation includes, for example and without limitation, an isolation of a peak value associated with the normalized Hue histogram by the controller 108 or other suitable component associated with the document processing device 104, by the workstation 130, or via other suitable device capable of performing the operations set forth in
According to one example implementation of the subject application, the peak value (facial tone index or iHmax) is compared to a preselected range of values. According to one embodiment of the subject application, the Hue values range from 0 to 100 representing the scaled 360 degrees of the Hue angle in Lightness, Chroma, and Hue color space. In accordance with one embodiment of the subject application, the preselected range of Facial Tone Indices is approximately 0 to 35.
One potential application of the facial tone index is to identify false positives in face detection.
In accordance with the preceding example implementation, upon a determination that the candidate facial region is not a false positive, i.e. the facial tone index (peak value) of the Hue histogram is within the preselected range, the controller 108 or other suitable component associated with the document processing device 104, the workstation 130, or other suitable device compares the histogram data to each of a plurality of preselected ranges of index values associated with a human ethnicity. A Facial Tone Index is then output for the candidate facial region based upon the results of the comparison. Thereafter, flesh tone correction is selectively applied to the pixels in the candidate facial region. A determination is then made at step 1020 whether another candidate facial region remains in the input image for analysis. Upon a determination at step 1020 that at least one additional candidate region remains in the input image, operations return to step 1006, whereupon at least one candidate facial region is isolated from the input image data. Thereafter, operations proceed from steps 1008 through step 1020 until a determination is made at step 1020 that no additional candidate facial regions remain, whereupon operations terminate with respect to
It will be appreciated by those skilled in the art that when the Facial Tone Index of a detected facial region is within the normal range, but close to the boundaries, e.g. greater than 27 or less than 7, it is possibly a candidate for flesh tone correction.
The foregoing description of a preferred embodiment of the subject application has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the subject application to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiment was chosen and described to provide the best illustration of the principles of the subject application and its practical application to thereby enable one of ordinary skill in the art to use the subject application in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the subject application as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.
