Apparatus for and method of edge enhancement in image processing

CROSS REFERENCE TO RELATED APPLICATION

The This invention claims priority of Korean Patent Application No. 2003-54648, which on 7 August 2003 the Korean Intellectual Property Office (Korean Office Intellectual property) has been submitted and the disclosure of which hereby is incorporated by reference.

BACKGROUND THE INVENTION

Field of the Invention

The This invention relates to an apparatus and a method to perform an edge enhancement or edge enhancement in a widely used known digital camera, such as a portable digital camera, having a low number of image pixels, and more particularly an apparatus and method for edge enhancement to simultaneously both an edge enhancement process and an interpolation without an additional Circuit or block perform edge enhancement.

In a portable digital camera, or a known widely used Digital camera does not appear a sensed or captured image alive because image sensor and lens of small size are, and the function of a photo-processing ICs for cost reduction has been greatly simplified. In particular, the border and the border a captured image is out of focus or blurry. To prevent the captured image is blurred, is a method of edge enhancement applied in the digital camera to the edge of the captured image strengthen and to obtain a vivid image captured.

The includes edge of a captured image information about the captured image itself. The edge of the captured image, the Limit is where the position, shape and size of a changed object of the captured image will. The edge of the captured image is located at a point, where the brightness of the captured image of a high brightness level low level to a low brightness or the level of Brightness to the level of large Brightness changes.

As above described, the process is edge enhancement used to the vivid image captured widely used in the to get known camera covers which image pixels whose number less than constituting a default. Of several methods for Edge enhancement is a process for detecting the edge of a original Image widely applied using various methods applied and the detected edge is added to the original image, around the edge of the original Image highlight.

The A method for edge enhancement is according to the type or the type of an input image assigned to one of various methods, and a very fast and very simple method for edge enhancement is to calculate pixel data of a center pixel and of neighboring pixels of the center pixel to determine a maxi mum value. This method is either a homogeneity operator method or Difference operator method.

<figref idrefs="S33">1A</figref> and <figref idrefs="S34">1B</figref> are views which conventional Method with a homogeneity operator or explain a difference operator. As in <figref idrefs="S33">1A</figref> is shown the homogeneity operator method comprises Forming a window with 3 × 3 Pixels, subtracting the pixel values ​​of around the center pixel of the window arranged neighboring pixels, from a pixel value of the center pixel for calculating differences, and outputting a maximum Absolute value among the absolute values ​​of differences at baseline. There wherein homogeneity operator method the calculating of the differences between the pixel value of the center pixel and the pixel values ​​of neighboring pixels of the window is carried out, are necessary with respect to the center pixel of the window 8 subtraction.

As in <figref idrefs="S34">1B</figref> is shown, comprising the difference operator method comprises calculating a first difference between pixel values ​​of an upper left pixel and a lower right pixel of the center pixel, the calculation of a second difference between pixel values ​​between an upper central pixel and a lower average pixel of the center pixel, the calculation of a third Difference between pixel values ​​of an upper &lt;?page 3?&gt;right pixel and a lower left pixel of the center pixel and calculating a fourth Difference between pixel values ​​of a middle-left pixel and a middle right-hand pixel of the center pixel. Since the difference operator method 4 subtraction requires in relation to the center pixel, is the difference operator method during execution the subtraction operation faster than the homogeneity operator method.

The above homogeneity and difference operator method are with respect to a black / white picture with a brightness component performed.

Various A method for edge enhancement are for a color image, which is not the Black / White, applied. Generally, in the color image with an RGB (R, G, and B components) color space operations in reference to the pixel values ​​of each color component R, G or B performed, and a gray scale edge image is made using the following formula 1 the results of operations created.

<img img-content="mf" img-format="tif" he="5" wi="52" file="00040001.tif" /> &lt;F1&gt;

Here in is G_red for a pixel value of a red component, G_green stands for the Edge image of a green component and G_blue represents the edge image of a blue component.

though is in a HSV (hue, saturation, value-hue, saturation and value (brightness or luminance) components) space, the edge the color image from the value (V) component of the hue (H) -, saturation (S) - and value (V) components detected. Therefore, it is possible to Edge of the color image rather by taking the value (V) component instead of all the color components, such as the H, S and V components, to recognize.

<figref idrefs="S35">2</figref> shows a block diagram a conventional Edge recognition device, which under the edge of the color image recognizes recourse a luminance. Referring to<figref idrefs="S35">2</figref> is from an image sensor <figref>201</figref> detected perceived image in a memory <figref>202</figref> as a Bayer pattern or Bayer pattern ge stores. Since 3 or more data components required are to realize the color image, pixel values ​​of three independent color (R, G and B) components are used as data components. The color image sensing image sensor <figref>201</figref> requires Color filter array (CFA), which are arranged in color sensors. Each color sensor of the image sensor <figref>201</figref> the pixel value taken from one of the color components with respect to each pixel, other Color components of the pixel, which is not removed with regard to the pixel be able by the CFA using information from neighboring pixels of the pixel to be calculated. This method is a commonly known Bayer pattern method, which corresponds to a CFA method. The recovery of the color image by the image sensor <figref>201</figref> is with the CFA called interpolation and demos-icing.

The in the memory <figref>202</figref> captured image (image information) becomes an RGB pattern image in a 3 × 3 line interpolation <figref>203</figref> processed.

Under Assuming that the interpolation unit <figref>203</figref> a 3 x 3-line interpolation with respect to the image information as the Bayer pattern in a Unit of a 3 × 3 window with the number of 3 × 3 Pixels is stored, carried, as the Bayer pattern is one of four patterns, is the 3 × 3 window of a the following four patterns represent. <ul><li>00: rgrgrg .... gbgbgb ....</li><li>01: BGBGBG .... GRGRGR ....</li><li>10: gbgbgb .... rgrgrg ....</li><li>11: GRGRGR .... BGBGBG ....</li></ul>

If a 3 x 3-line Bayer pattern, this in <figref idrefs="S36">3A</figref> is shown the interpolation unit <figref>203</figref> is supplied, provide the RGB values ​​of the RGB pattern as follows. &lt;?page 4?&gt;<st32:df xmlns:st32="http://lighthouseip.com/">R = (R1 + R2 + R3 + R4) / 4 G = (G1 + G2 + G3 + G4) / 4 B = B1</st32:df>

If the 3 × 3 line Bayer pattern, this in <figref idrefs="S36">3B</figref> is shown the interpolation unit <figref>203</figref> is supplied, the RGB values ​​of the RGB pattern as follows. <st32:df xmlns:st32="http://lighthouseip.com/">R = (R1 + R2) / 2 G = G3 B = (B1 + B2) / 2</st32:df>

If the 3 × 3 line Bayer pattern, this in <figref idrefs="S37">3C</figref> is shown the interpolation unit <figref>203</figref> is delivered, loud the RGB values ​​of the RGB pattern as follows. <st32:df xmlns:st32="http://lighthouseip.com/">R = (R1 + R2) / 2 G = G3 B = (B1 + B2) / 2</st32:df>

If the 3 × 3 line Bayer pattern, this in <figref idrefs="S37">3D</figref> is shown the interpolation unit <figref>203</figref> is supplied, the RGB values ​​of the RGB pattern as follows. <st32:df xmlns:st32="http://lighthouseip.com/">R = R1 G = (G1 + G2 + G3 + G4) / 4 B = (B1 + B2 + B3 + B4) / 4</st32:df>

The 3 x 3-line Bayer pattern interpolation a method of calculating a mean of the pixel values Neighboring pixels excluding those pixels with a maximum or minimum pixel value and the method described above include. To perform the 3 × 3-line interpolation, should transfer 3 line data simultaneously to an image processor will.

The in the interpolation <figref>203</figref> interpolated RGB pattern Image is in an edge detection device <figref>206</figref> through a YCrCb (YUV) -Musterkonverter <figref>204</figref> and a further memory <figref>205</figref> processed.

If However, the interpolation and edge enhancement on the detected Image by using the above conventional methods are performed, to realize a processed image block, a time lag occurs between the input image and the output image, since the interpolation and edge enhancement are performed in the unit of a frame, and also be a frame buffer and an additional memory needed storing the input image and the edge image temporarily because the interpolation and the edge enhancement in the unit of Framework conducted will.

The captured image looks not alive, since the functions of image processor ICs have been simplified to reduce costs too much to get a clear Image capture image as input (perceived), and the image sensor and the lens of the digital camera with a low number of pixels are of only small size. In particular, the edge (the edge) of an object in the captured Picture is blurred. Although the edge of the object of the captured image using the conventional can be strengthened process for edge enhancement to a livelier to obtain image, requires a device for edge enhancement, the conventional the A method for edge enhancement applies, in addition to an interpolation processing unit (A block) as shown in <figref idrefs="S35">2</figref> shown is an additional Functional unit (one block).

The Japanese Patent Publication Nos. Hei 7-107268 discloses a conventional image processing device to obtain information with a high resolution for a sharp edge by Calculating the high-resolution Information that the resolution information is adjacent, in a linear interpolation and by add the edge information of an edge information unit to the linear interpolated high resolution information.

There However, the above conventional image processing apparatus an apparatus for processing an edge processing operation after performing represents the interpolation of additional functional block is next the interpolation block required. Furthermore, the foregoing conventional image processing apparatus not right in Digital camera, or the well-known popular Digital&lt;?page 5?&gt;camera be used.

It is necessary that a new process for the simultaneous implementation of Edge enhancement and interpolation without an additional Function block in the digital camera or the well-known popular Digital camera regardless of the size or the cost of image processing ICs can be easily used.

Out US 2002/0012055 A1 is a digital still camera system and a method therefor known. Raw data are here interpolated. Scroll through the raw data initially interpolation. In this interpolation of the green channel interpolated, and the green Channel are detected edges. Purpose of which is the focus of the to improve the image (<figref>27</figref>).

Out JP 06-309452 A is a resolution conversion processor known. An edge detection part judges whether a pixel close a straight edge is. A first Interpolationsverarbeitungsteil calculates a pixel value of an arbitrary pixel position by interpolating the input image data. A high-band emphasis part leads the clearance processing the input image data. A second Interpolationsverarbeitungsteil receives the output of the emphasis part and calculates a pixel value at the same pixel position as the first Interpolationsverarbeitungsteil. An adder leads the weighting operation the results of the first and second Interpolationsverarbeitungsteile by proviso the extent nearby the processed pixel in an edge region by means of the issue the edge judging part through.

Out of the <patcit><text>US 6563537</text></patcit> is known image signal interpolation. Based on 4 pixels, the a target pixel are adjacent, it is judged whether the target pixel an edge forms and if so, whether the edge or horizontally extends vertically. When an edge is present, an appropriate interpolation is performed.

SUMMARY THE INVENTION

to solution the above problem, and / or other problems, it is a Aspect of the present invention to provide an apparatus and method An edge enhancement available make to order by providing a simple circuit at the Device, which emphasizes a screen edge, a more vivid to obtain image without enlarging the image processing unit.

It is a further aspect of the present invention, an apparatus and a process for edge enhancement or strengthening of a Picture edge available provide, without an additional Memory than the line memory for storing an input image provide, which is required when an edge emphasizing using an additional Function block or an additional Edge image is realized.

It is a further aspect of the present invention, an apparatus and a method of edge enhancement available to set to the same time a 3 × 3-interpolation and to process edge enhancement to some an output image with only few bars delay without a maximum frame delay, which occurs when interpolation and edge enhancement block be realized in separate circuit blocks, outputting.

More Aspects and / or advantages of the invention will in part, in the following running Description and partly obvious from the description, or may be prepared by Implementation of the invention will learn into practice.

The Objects of the invention are solved with the feature of the independent claims. Dependent claims are to preferred embodiments shaper the invention is directed.

SHORT DESCRIPTION THE DRAWINGS

The foregoing and other advantages of the invention appear from the following description of the preferred embodiments together with the verstan accompanying drawings and better&lt;?page 6?&gt;the, wherein:

<figref idrefs="S33">1A</figref> and <figref idrefs="S34">1B</figref> views show which conventional one Homogeneity operator method or a conventional explain difference operator procedures;

<figref idrefs="S35">2</figref> on Block diagram of a conventional Edge detection device shows which under an edge attraction a luminance recognizes;

<figref idrefs="S36">3A</figref> to <figref idrefs="S37">3D</figref> 3 × 3 window show, which are formed when a Bayer pattern using of a 3 x 3-line interpolation is interpolated;

<figref idrefs="S38">4</figref> on Block diagram of an edge enhancement device according to a embodiment the present the invention; and

<figref idrefs="S39">5</figref> on Block diagram of a further edge enhancement device according to a Alternatively, of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

It will now be in detail to the present preferred embodiments of taken to the present invention, examples of enclosed in the Drawings are illustrated, wherein like reference numerals consistently refer to the same elements. The embodiments be described below to the present invention by Referring to explain to the figures.

According to a Aspect of the present invention comprise the method and Apparatus for edge enhancement is a method for detecting a Edge of a luminance component (luminance) of image data and for highlighting the edge as the simplest method of various edge detection methods and -hervorhebungsverfahren. Since most edges same edge as the luminance show the edge under recourse is recognized the luminance and highlighted.

The Corresponds to the luminance component Y of a YCrCb or the YUV color space. According to the CCIR 6-1 YCrCb color space conversion formula is the G-component of R, G, and B for Y is the most significant, since a coefficient of R 77 is, is a coefficient of G 150 and a coefficient of B is 29. Therefore, the Y of the YCrCb color space or the G component of RGB color space as the luminance component be used to detect and to emphasize the edge. &lt;CCIR 6-1 YCrCb color space conversion formula&gt;<tables><table><tgroup cols="2"><colspec colname="1" colwidth="1*" /><colspec colname="2" colwidth="1*" /><tbody><row><entry colname="1">Y = (77R + 150G + 29B) / 256</entry><entry colname="2">Area: 16 ~ 235</entry></row><row><entry colname="1">Cb = (-44R - 87G + 131B) / 256 + 128</entry><entry colname="2">Area: 16 ~ 240</entry></row><row><entry colname="1">Cr = (131R - 110G - 21B) / 256 +128</entry><entry colname="2">Area: 16 ~ 240</entry></row></tbody></tgroup></table></tables>

at the method for detecting the edge by reference to the luminance component is it when an image sensor an image processor for outputting RGB data, such as YUV data, the interpolation process in a have been processed, which desirable that the edge using the luminance component, such Example Y, is detected by each pixel. If the RGB data, the not been processed in the interpolation process, output are, the RGB format of RGB data needs in a YCrCb or YUV format be converted to the edge of the RGB data in the image sensor, the the image processor not to recognize. In this case, an additional Storage space for use in an edge detection process requires.

There the method and apparatus for edge enhancement, interpolation and the edge enhancement in an image device of low Size with a mobile device, such as a wireless phone, may be connected, in a very simple structure in accordance with a Aspect perform a further aspect of the present invention is the method for detecting and highlighting the edge using the G component which affects the luminance most, used in the method and the device for edge enhancement.

The used in the process and the apparatus for edge emphasizing edge detection&lt;?page 7?&gt;The procedure compares the G value of a center pixel a frame contained in a 3 × 3 window with GSM values ​​of neighboring pixels of the center pixel to the edge by reference to the difference between the G value of the center pixel and the G values ​​of the adjacent pixels to recognize.

As in the <figref idrefs="S36">3A</figref> to <figref idrefs="S37">3D</figref> shown is, with respect to the 3 × 3 window of 4 different Bayer-pattern the edge by comparing the G value of the center pixel of the 3 × 3 window with the G values ​​of the neighboring pixels of the center pixel and by calculating a maximum difference among the differences between the G value the center pixel and the G-values ​​of neighboring pixels judged as an edge.

The Method and apparatus for edge enhancement lead the Recognizing and highlighting the edge according to another aspect of the present invention by simultaneously. The edge enhancement operation is not performed to the image data to be highlighted. Of the G-value of the center pixel and the four G-values ​​of the four neighboring pixels are compared, since one of the RGB components in the Bayer pattern present.

<figref idrefs="S36">3A</figref> and <figref idrefs="S37">3D</figref> show the center pixel having a B value or a R value, rather than the G value. There the G value showing data from that on the B and the R-value based interpolation achieved are generated, is in itself the G-value is not data output from the image sensor, but to calculated data from the interpolation of the B value and R-value are obtained. Accordingly, the edge is in the<figref idrefs="S36">3A</figref> and <figref idrefs="S37">3D</figref> not calculated.

In the <figref idrefs="S36">3B</figref> and <figref idrefs="S37">3C</figref> becomes a multiplication value by multiplying with the 4 G-value of the center pixel is calculated from the sum of the G values the four neighboring pixels subtracted to an edge detection value to calculate (a signal) X, which is calculated from the following formula 2 becomes. <st32:df xmlns:st32="http://lighthouseip.com/">Edge detection value (X) = 4G3 - (G1 + G2 + G3 + G4) &lt;Formula 2&gt;</st32:df>

Here in the G value of the center pixel with four is multiplied because the Number of neighboring pixels is four. If the edge is not in a of the 3 × 3 window surrounded portion is present; are similar to one another in the 3 × 3 window disposed G values, and a difference between the multiplication value and the sum of is close to zero. This means that the detection value X is zero. In contrast, when the edge in the 3 x 3 window is present, is a the G values ​​of neighboring pixels due to differences between the luminance is greater than the other G-values, and an absolute value of the difference between the multiplication value and the sum is important to show that the edge in the 3 x 3 window is present.

Even when the edge detection value X is recognized by a point, which is disposed adjacent to the center pixel, the above Edge methods used in the edge enhancement device , since no significant effect on an image with highlighted Edge is present, except the image is enlarged or reduced to a minimum, and since it is a further aspect of the present Invention is to realize the edge enhancement in an extremely simple manner.

In this case, a threshold value can be set. If the edge detection value X is greater than the Threshold value, it is determined that the edge in the 3 × 3 window present. If the Kantenerken voltage value not greater than X the threshold value, it is determined that the edge in the 3 × 3 window is not present.

The The method and the device for edge detection according to a another aspect of the present invention perform edge detection and the edge enhancement of using a line memory, for the application of a 3 × 3 interpolating used in the edge enhancement without any additional memory becomes.

<figref idrefs="S38">4</figref> is a block diagram of the edge enhancement device according to a embodiment of the present invention. A process of edge enhancement is with reference to <figref idrefs="S38">4</figref> described in detail.

As in <figref idrefs="S38">4</figref> As shown, image data is a captured Image with pixel lines in the unit of a frame of an image sensor <figref>415</figref> at a line buffer <figref>401</figref> output. The line buffer<figref>401</figref> stores the input image data temporarily and outputs the stored image data in a unit of three lines to Interpolation. The 3-line image data by a register<figref>402</figref> in an interpolation unit <figref>403</figref> entered.

&lt;?page 8?&gt;

A Output of the line buffer <figref>401</figref> is a left exit the register <figref>402</figref> transmitted and then to a right terminal of the register <figref>402</figref> shifted. Accordingly, the 3 × 3 window corresponding Image data in the register <figref>402</figref> saved, and the 3 × 3 window is the register <figref>402</figref> shifted according to each clock. The 3 × 3 window is clocked according to the right shifted in the interpolation unit <figref>403</figref> entered to become.

The interpolation <figref>403</figref> performs the 3 × 3-line interpolation on the image data of pixel values ​​by which described the 9 above from the register <figref>402</figref> received corresponding to pixels.

A RGB to YCrCb conversion unit <figref>404</figref> convert the RGB data, which in the interpolation <figref>403</figref> are interpolated in the data from the YCrCb format or the data from the YUV format, to a Display device or a memory unit are output.

<figref idrefs="S38">4</figref> shows Circuits such as a control unit <figref>405</figref> and an edge detection device <figref>406</figref>, For carrying out the Edge detection and edge enhancement.

The control unit <figref>405</figref> transmits a signal pattern, the information on representing a pattern of the 3 × 3 window, the interpolation unit <figref>403</figref>, The pattern signal the by the image sensor <figref>415</figref> is produced Bayer pattern, is supplied to the interpolation unit <figref>403</figref> transfer.

In the case in which the image sensor <figref>415</figref> the non-image processor comprises, are the from the register <figref>402</figref> the interpolation unit <figref>403</figref> transmitted Image data, the Bayer pattern.

In this case, the Bayer pattern of the following four patterns. <ul><li>00: rgrgrg .... gbgbgb ....</li><li>01: BGBGBG .... GRGRGR ....</li><li>10: gbgbgb .... rgrgrg ....</li><li>11: GRGRGR .... BGBGBG ....</li></ul>

The means that the control unit <figref>405</figref> the pattern signal, which represents which of the four patterns in the interpolation unit <figref>403</figref> transmitted Bayer pattern is, the interpolation unit <figref>403</figref> transfers.

If the pixel value of the center pixel, which in the register <figref>402</figref> saved 3 × 3 window accounts, the G value is, the G-value is multiplied by 4, and the multiplication is the sum of four adjacent of the center pixel distributed values ​​subtracted to give the edge detection value X.

If the pixel value of the center pixel of the 3 × 3 window is not the G-value, the Edge detection value X not to the first adder <figref>408</figref> transfer.

As in <figref idrefs="S38">4</figref> shown, receives the interpolation <figref>403</figref> the Pattern signal from the control unit <figref>405</figref>To that of the register <figref>402</figref> to determine received Bayer pattern.

The interpolation <figref>403</figref> generates a selection signal of the Value 0 to the edge detection unit <figref>406</figref>To the edge detection unit <figref>406</figref> off, when in the interpolation <figref>403</figref> input pattern of the window indicates that the pixel value of the center pixel of the B-value or R-value rather than the G value is, as shown in <figref idrefs="S36">3A</figref> and <figref idrefs="S37">3D</figref> shown is. interpolation<figref>403</figref> generates the selection signal of the value 1 of an AND gate <figref>414</figref> the edge detection unit <figref>406</figref>. around the edge detection value X of the edge detection unit <figref>406</figref> at a first adder <figref>408</figref> output when in the interpolation <figref>403</figref> entered Pattern of the window indicates that the pixel value of the center pixel of the G value is, as shown in <figref idrefs="S36">3B</figref> and <figref idrefs="S37">3C</figref> shown is. The edge detection unit<figref>406</figref> performs a calculation process at the G value Gc of the center pixel, which in a central portion of the 3 × 3 window is arranged, and at the G1, G2, G3, G4-values ​​of the pixels, which are arranged adjacent to the center pixel. The edge detection value X is calculated by the following formula. <st32:df xmlns:st32="http://lighthouseip.com/">Edge detection value (X) = 4Gc - (G1 + G2 + G3 + G4)</st32:df>

&lt;?page 9?&gt;

In the calculation process of the edge detection unit <figref>406</figref> added a second adder <figref>410</figref> G1 to G3 to obtain a first sum G1 + G3 output, a multiplier <figref>411</figref> multiplied the G value Gc of the center pixel 4, by a multiplication value outputting 4Gc, a third adder <figref>413</figref> added to G2 G4 to output a second sum G2 + G4, and a fourth adder adds the first sum G1 + G3, the multiplication value and 4Gc the second sum G2 + G4 to output the edge detection value X, namely 4Gc - (G1 + G2 + G3 + G4).

As It was described above, is when the edge in a portion of the image data which in the register <figref>402</figref> stored 3 × 4 window meet, is not present, the addition to the value of 4Gc - (G1 + G2 + G3 + G4) corresponding edge detection value X to zero, the called, the edge detection value (X) = 0, since almost all of the pixel values in the 3 × 3 window arranged pixels each are similar. In contrast, decreases as the edge in the image data portion of the exists that the in the register <figref>402</figref> stored 3 × 4 window match, an absolute value of the edge detection value X, of the Addition value of 4Gc - (G1 + G2 + G3 + G4), corresponds to a larger value, that is, the Edge detection value (X) varies because some of the pixel values to the center pixel of the 3 × 3 window pixels arranged in accordance with the luminance of each other differ.

Of the from the fourth adder <figref>412</figref> output edge detection value X and that of the interpolation <figref>403</figref> output will select signal an addition process in the AND gate <figref>414</figref> entered. interpolation <figref>403</figref> determines the on the of the control unit <figref>405</figref> transmitted Pattern signal based Bayer pattern, transmits the selection signal from the value 0 to the AND gate <figref>414</figref>. if the pixel value of the center pixel of the 3 × 3 window of the R- or B-value instead of in the register <figref>402</figref> stored G-value, and transmits the selection signal from the value 1 to the AND gate <figref>414</figref>If the pixel value of The center pixel of the 3 × 3 window the G-value.

If the selection signal is 0, that is, a switched-off state, which represents that the pixel value the center pixel of the R or B value instead of G-value, the edge detection value X not to the first adder <figref>408</figref> transfer. When the selection signal 1, that is, a released state, which represents that the pixel value of the center pixel of the G-value is the edge detection value X is supplied to the first adder <figref>408</figref> transfer.

Of the Edge detection value X becomes an issue Gaus of interpolation <figref>403</figref> in the first adder <figref>408</figref> added to the output Gaus highlight. Accordingly, when the image data, the edge have after they have been interpolated, the highlighted image data, to the highlighted value (the signal) G 'to the RGB to YCrCb (YUV) -Konvertierungseinheit <figref>404</figref> as follows output. <st32:df xmlns:st32="http://lighthouseip.com/">G '= X + Gaus</st32:df>

<figref idrefs="S39">5</figref> is a block diagram of a further edge enhancement device an image sensor <figref>515</figref>, A line buffer <figref>501</figref>. a register <figref>502</figref>, An interpolation unit <figref>503</figref>. an RGB to YCrCb (YUV) -Konvertierungseinheit <figref>504</figref>. a control unit <figref>505</figref>, An edge detection unit <figref>506</figref>. a comparison unit <figref>507</figref> and a first adder <figref>508</figref> according to a another embodiment of the present invention. The edge detection unit<figref>506</figref> includes a second adder <figref>510</figref>, A first multiplier <figref>511</figref>. a third adder <figref>513</figref>, A fourth adder <figref>512</figref> and an AND gate <figref>514</figref>, With reference to<figref idrefs="S39">5</figref> determines the control unit <figref>505</figref> a predetermined reference value CV corresponding to the edge detection signal X, and the edge is highlighted when the edge detection unit <figref>506</figref> recognized Edge detection signal X is larger than the reference value CV is.

The Block diagram of the <figref idrefs="S39">5</figref> is similar to the block diagram of the <figref idrefs="S38">4</figref> With Except for the control unit <figref>404</figref>Which the reference value CV determines the comparison unit <figref>507</figref>Which value for edge detection X compares with the reference value CV, and a second multiplier <figref>509</figref>,

Of the from the fourth adder <figref>512</figref> the edge detection unit <figref>506</figref> output Edge detection value is X together with one of the interpolation <figref>503</figref> issued Selection signal is input to the AND gate, by the addition operation perform. interpolation <figref>503</figref> determines on the pattern signal by the controller <figref>505</figref> based Bayer pattern, transmits to the Edge detection unit <figref>506</figref> the selection signal from the value 0 if the pixel value of the center pixel of the 3 × 3 window not the G value, but the R- or B-value, and transmits to the Edge detection unit <figref>506</figref> the selection signal from the value 1, if the pixel value of the center pixel of the 3 × 3 window is the G value.

&lt;?page 10?&gt;

If the selection signal has the value 0, that is, if the pixel value of The center pixel of the 3 × 3 window not the G value, but the R- or B-value, the edge detection signal is X not to the comparison unit <figref>507</figref> and the first adder <figref>508</figref> transfer. In contrast to this, when the selection signal has the value 1, this means, if the pixel value of the center pixel of the 3 × 3 window is the G value, the edge detection value X to the comparison unit <figref>507</figref> and the first adder <figref>508</figref> transfer, and the comparison unit <figref>507</figref> compares the by the control unit <figref>505</figref> entered Reference value CV with the edge detection unit <figref>506</figref> issued Edge detection signal X to the presence of the edge in the 3 × 3 window to determine.

Of the by the controller <figref>505</figref> output reference value CV can be adjusted according to the level of edge enhancement. When the reference value CV will be set to a low value, a stopped down portion of the 3 × 3 window, that is, a Section with a very small change of an object of image data, reinforced are to highlight a blurred boundary of the object.

In a further portion of the 3 × 3 window, in the changes the image data are, the edge of the object is highlighted to alive Act. The need for edge enhancement varies depending on Type or use of the image data, and the reference value CV is accordingly the need for edge enhancement set.

in the Case of an 8-bit image frame is the G-value between 0 255. In general the reference value is set to 64. The edge occurs when the edge detection value X is greater than the reference value CV is, and the edge is not present, if the edge detection value X is not greater than the reference value CV is.

The comparing unit <figref>507</figref> is a value or weighting a when the edge according to a Comparison result between the edge detection value X and the reference value CV is present. Of the comparison unit<figref>507</figref> output Value is to that of the edge detection unit <figref>506</figref> issued Edge detection value X multiplied by the modified detection signal a · outputting X, and the modified detection signal a · X is to the G output value Gaus the interpolation unit <figref>503</figref> among the outputs of the interpolation <figref>503</figref> added. Therefore, if the edge is present, after the pixel value in the interpolation <figref>503</figref> was interpolated, which at the RGB to YCrCb conversion unit <figref>504</figref> transmitted highlighted signal G 'with reference to the following Formula are calculated. <st32:df xmlns:st32="http://lighthouseip.com/">G '= G<st32:sub>out</st32:sub> + A · X</st32:df>

As in the above formula is shown, the output value is G- Gaus of interpolation highlighted according to the valence. If the value a is set to a relatively large value, exaggerated the edge enhancement operation executed so that the object of the image data is out of focus. It is possible that the valence a is in a range between 0 to 1.

If it is found that according to the comparison result the edge detection value X and the reference value CV in the comparison unit <figref>507</figref> the Edge is not present, the comparison unit <figref>507</figref> the Value of 0, which with the edge detection value X in the second multipliers <figref>509</figref> is multiplied so that the edge detection value X is shifted or offset. Therefore, the output Gaus the interpolation unit <figref>503</figref> not highlighted to at the RGB to YCrCb conversion unit <figref>504</figref> output to be. This means, G '= Gaus.

As above described, since the register <figref>502</figref>. which the 3-line Bildaten the interpolation unit <figref>503</figref> provides that the 3 × 3-interpolation points out, simultaneously or frequently for edge detection and -hervorhebungsschaltkreise, such as the control unit <figref>505</figref>. edge detection unit <figref>506</figref>, The comparison unit <figref>507</figref> and the second multiplier <figref>509</figref>Is used, either a additional Memory needed yet the manufacturing cost increases. Therefore, this structure acts not to total IC area an image processing unit, even if the proceeding described vorste Edge detection and -hervorhebungsschaltkreise in the image processing unit the device can be used for edge enhancement.

According to the apparatus edge detection and -hervorhebung is a simple circuit to gain the edge added, to obtain a vivid image, without increasing the total IC area.

&lt;?page 11?&gt;

According to the apparatus are edge detection and -hervorhebung when the edge detection and -hervorhebungsschaltkreise in a separate block (one unit) be implemented in the image processing unit to the edge the image enhance, no line memory and no additional Memory required to store the image edges, necessary.

According to the apparatus edge detection and -hervorhebung be the 3 × 3 interpolation and edge enhancement performed simultaneously without clock delay, in Comparison with the possibility that a frame delay occurs when the edge detection and -hervorhebungsschaltkreise in a separate block (one unit) in the image processing unit be implemented to emphasize the edge of the image.