JP2012068905A - Image processing apparatus, image processing method, and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To raise the image quality at the circumference of an output image without increasing the necessary memory capacity and load when an input image is scaled to generate the output image.SOLUTION: An image processing apparatus 5 segments a segmented image having a segmentation resolution from the input image, performs resolution conversion on the segmented image, generates an enlarged image with a higher resolution than the output resolution, and generates the output image by extracting a part corresponding to the output resolution from the generated enlarged image.

Description

  The present invention relates to an image processing apparatus, an image processing method, and a display apparatus that perform enlargement / reduction of an image.

  Conventionally, a method for generating an output image by cutting out a part of an input image and enlarging or reducing the image when enlarging or reducing the image is known (see, for example, Patent Document 1). In this method, a part of the input image is cut out with a size corresponding to the resolution and the enlargement / reduction ratio of the output image, and resolution conversion is performed according to the enlargement / reduction ratio. When an output image having a higher resolution than an image cut out by this resolution conversion is generated, pixel information of many pixels is generated from pixel information of pixels having a small input image, for example, by interpolation calculation. Specifically, the pixel information of the output image is calculated from the pixel information of the input image at a position corresponding to the pixel and a plurality of surrounding pixels.

JP 2005-109708 A

When the resolution of an image is increased using a technique such as an interpolation operation as in the method described in Patent Document 1, the pixel information of one pixel is calculated based on the pixel information of a plurality of pixels. A quality output image is obtained. However, pixels located at the end of the output image must obtain pixel information from the pixels at the end of the input image. That is, since no pixel exists outside the edge of the input image, the pixel information at the edge of the output image is calculated from the pixel information of fewer pixels. For this reason, there has been a problem that the image quality is deteriorated at the peripheral portion of the output image. In addition, if the size of the image that is the basis of the arithmetic processing is increased or the arithmetic processing is complicated in order to solve this problem, the required memory capacity and hardware performance will increase dramatically, making it difficult to implement. There was a problem of becoming.
The present invention has been made in view of the above-described circumstances. When an output image is generated by enlarging or reducing the input image, the image quality at the periphery of the output image is increased without increasing the necessary memory capacity or load. The purpose is to increase.

In order to achieve the above object, the present invention provides an image processing apparatus for generating an output image having a predetermined output resolution from an input image, wherein the clipped image having a cutout resolution is cut out from the input image. An output processing unit, and converting the resolution of the cut image to generate an enlarged image having a higher resolution than the output resolution, and extracting the portion corresponding to the output resolution from the generated enlarged image And an enlarging processing means for generating.
According to the present invention, after an enlarged image having a resolution higher than the output resolution is obtained, an output image is generated by extracting a portion corresponding to the output resolution from the enlarged image. Therefore, the output image is an image after resolution conversion. The image is obtained by removing the peripheral edge portion of. For this reason, since the low-quality portion generated at the peripheral portion during resolution conversion is removed, the extracted output image can be expected to have high image quality up to the peripheral portion, so that the image quality of the output image is improved. be able to. Further, the process of extracting a part from the image after resolution conversion can be executed without storing the converted high-resolution image in the memory, and can be realized without increasing the necessary memory capacity and load.
Here, the enlargement factor includes an enlargement factor of 1 or less, that is, a magnification when the input image is reduced.

Further, in the image processing apparatus according to the present invention, the enlargement processing unit converts a horizontal resolution of the cut image, and outputs the converted data for each horizontal line; Horizontal clipping means for clipping the portion corresponding to the output resolution from the data for each line output by the horizontal resolution conversion means, and outputting the data of the horizontally converted image for each line, and horizontal conversion clipped by the horizontal clipping means Storage means for sequentially storing image data; vertical resolution conversion means for converting the resolution in the vertical direction of the horizontally converted image stored in the storage means; and outputting the converted data for each vertical line; and the vertical The portion corresponding to the output resolution is clipped from the data for each line output by the resolution conversion means, and the output image data is output for each line. Characterized in that it comprises a vertical clip means for outputting.
According to the present invention, the horizontal resolution of the cut-out image is converted, the converted data is output for each horizontal line, and the portion corresponding to the output resolution is clipped from the data output for each line. That is, since the resolution conversion in the horizontal direction and the clipping to the data corresponding to the output resolution are executed for each line, it is not necessary to store the image in the memory during the conversion of the horizontal resolution and the clipping process. Therefore, the required memory capacity can be suppressed and the processing speed can be increased. Also for vertical resolution conversion, the image data stored in the storage means is read for each line in the vertical direction, the vertical resolution is converted, and an image having a higher vertical resolution than the output resolution is output. Clip the part corresponding to the output resolution from the image. This vertical resolution processing is performed for each line in the vertical direction, and it is not necessary to store image data in the memory during this processing, so the amount of memory used is reduced and the processing speed is further increased. Can be planned.

In the image processing apparatus according to the present invention, the horizontal resolution conversion means included in the enlargement processing means converts the horizontal resolution of the input image data to a higher resolution than the output resolution. .
According to the present invention, since the horizontal resolution conversion means converts the horizontal resolution of the clipped image to a higher resolution than the output resolution, the horizontal resolution of the clipped image is calculated from the output resolution and the enlargement factor. The required minimum resolution can be achieved. Thereby, it is possible to reduce the amount of data to be processed, reduce the load, and increase the processing speed. In addition, since an image having a higher resolution than the output resolution can be easily obtained, high image quality can be easily achieved.

In the image processing apparatus according to the present invention, the vertical resolution conversion unit included in the enlargement processing unit sets the vertical resolution of the horizontal conversion image stored in the storage unit to a higher resolution than the output resolution. It is characterized by converting.
According to the present invention, the vertical resolution conversion means converts the vertical resolution of the horizontal conversion image to a higher resolution than the output resolution, and therefore the vertical resolution of the cut-out image is obtained from the output resolution and the enlargement factor. The required minimum resolution can be achieved. Thereby, it is possible to reduce the amount of data to be processed, reduce the load, and increase the processing speed. In addition, since an image having a higher resolution than the output resolution can be easily obtained, high image quality can be easily achieved.

According to the present invention, in the image processing apparatus, the extraction processing unit extracts, from the input image, an area including more pixels than a necessary input image resolution obtained from the output resolution and the enlargement ratio. It is characterized by.
According to the present invention, when a cut image is cut out from an input image, an image with a resolution higher than the required resolution is cut out, so that an image with a resolution higher than the output resolution can be easily generated.

In order to achieve the above object, the present invention provides an image processing method for generating an output image having a predetermined output resolution from an input image, wherein the cut image having a cut resolution is generated from the input image. Cut out, convert resolution of the cut out image, generate an enlarged image having a higher resolution than the output resolution, and generate the output image by extracting a portion corresponding to the output resolution from the generated enlarged image It is characterized by that.
By executing the method of the present invention, it is possible to generate a high-quality output image in which the input image is enlarged by resolution conversion. That is, after obtaining an enlarged image with a resolution higher than the output resolution, a portion corresponding to the output resolution is extracted from the enlarged image to generate an output image. Therefore, the output image has a peripheral portion of the image after resolution conversion. The image is removed. For this reason, since the low-quality portion generated at the peripheral portion during resolution conversion is removed, the extracted output image can be expected to have high image quality up to the peripheral portion, so that the image quality of the output image is improved. be able to. Further, the process of extracting a part from the image after resolution conversion can be executed without storing the converted high-resolution image in the memory, and can be realized without increasing the necessary memory capacity and load.

In order to achieve the above object, the present invention provides a display device for generating an output image having a predetermined output resolution from an input image and displaying the generated output image, wherein the output image is cut from the input image. A cutout processing unit that cuts out a cutout image having an output resolution, and converts the resolution of the cutout image to generate an enlarged image having a higher resolution than the output resolution, and corresponds to the output resolution from the generated enlarged image The image processing apparatus includes an enlargement processing unit that generates the output image by extracting a portion to be displayed, and a display unit that displays the output image generated by the enlargement processing unit.
According to the present invention, a high-quality output image obtained by enlarging an input image by resolution conversion can be displayed. That is, after obtaining an enlarged image with a resolution higher than the output resolution, a portion corresponding to the output resolution is extracted from the enlarged image to generate an output image. Therefore, the output image has a peripheral portion of the image after resolution conversion. The image is removed. For this reason, since the low-quality portion generated at the peripheral portion during resolution conversion is removed, the extracted output image can be expected to have high image quality up to the peripheral portion, so that the image quality of the output image is improved. be able to. Further, the process of extracting a part from the image after resolution conversion can be executed without storing the converted high-resolution image in the memory, and can be realized without increasing the necessary memory capacity and load.

  According to the present invention, it is possible to improve the image quality of the output image including the peripheral edge by cutting out a part of the input image and converting the resolution without increasing the necessary memory capacity and load.

It is a block diagram which shows the functional structure of the display apparatus which concerns on embodiment to which this invention is applied. It is a flowchart which shows operation | movement of the display apparatus which concerns on an enlarged display. It is a figure which shows an example of the process which expands an image, (A) is an input image, (B) is the clip image cut out from the input image, (C) is an image after horizontal resolution conversion, (D) is a horizontal direction (E) shows the image after the vertical resolution conversion, and (F) shows the image after the output vertical clip clipped in the vertical direction. It is a figure which shows the mode of a general resolution conversion, (A) shows arrangement | positioning of the pixel of the image before conversion, (B) shows arrangement | positioning of the pixel of the image after conversion. It is a figure which shows the mode of the resolution conversion which concerns on this embodiment, (A) shows the pixel arrangement | positioning in the image before conversion, (B) shows the pixel arrangement | positioning in the image after conversion, (C) is a clip. The arrangement | positioning of the pixel in a subsequent image is shown. It is a figure which shows the process which expands the image in a modification, (A) is an input image, (B) is a clip image cut out from the input image, (C) is an image after horizontal resolution conversion, (D) is horizontal The image after output horizontal clipping clipped in the direction, (E) shows the image after vertical resolution conversion, and (F) shows the image after output vertical clipping clipped in the vertical direction.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a functional configuration of a display device 1 according to an embodiment to which the present invention is applied.
A display device 1 shown in FIG. 1 is a projector that projects an image onto a screen SC. The light source device 2, a liquid crystal light valve 3 that modulates light emitted from the light source device 2, and light modulated by the liquid crystal light valve 3. And a projection optical system 4 for condensing and diffusing the light and projecting it on the screen SC.

The light source device 2 includes a light source including a xenon lamp, an ultrahigh pressure mercury lamp, an LED, a laser, and the like. The light source device 2 may include a reflector for guiding light emitted from the light source to the liquid crystal light valve 3 and an auxiliary reflector, and a lens group (not shown), a polarizing plate, or a light source for enhancing the optical characteristics of the projection light It may be provided with a light control element or the like for reducing the amount of light emitted from the light on the path to the liquid crystal light valve 3.
The liquid crystal light valve 3 includes, for example, three transmissive liquid crystal panels corresponding to RGB colors, and an image processed by the image processing device 5 is drawn on these transmissive liquid crystal panels.
The projection optical system 4 includes a prism that synthesizes RGB three-color modulated light modulated by the liquid crystal light valve 3, a lens group that forms a projection image synthesized by the prism on the screen SC, and the like. In addition, when the liquid crystal light valve 3 is composed of one transmissive liquid crystal panel, a member corresponding to a prism is unnecessary.
Each component relating to image display including the light source device 2, the liquid crystal light valve 3, and the projection optical system 4 corresponds to the display means of the present invention as a whole, but the liquid crystal light valve 3 particularly corresponds to the display means. To do. However, the configuration of the display means is not limited to the liquid crystal light valve 3, and if it is possible to display an image, a part or all of the display means can be replaced by the various functional units as described above.

The display device 1 receives an image signal from an image source (not shown) stored in a built-in storage device or an external image supply device (not shown) such as a personal computer or various image players. The image signal input to the display device 1 may be a still image or a moving image. Here, as an example, a case where digital image data of a still image is input will be described.
The display device 1 includes a control device 10 that controls the entire display device 1, an image processing device 5 that processes image data input from the image source or an external image supply device according to the control of the control device 10, and an image processing device 5. And a light source for turning on / off the light source device 2 by supplying a drive current to the light source device 2 in accordance with the control of the control device 10. A driving device 11 is provided. The control device 10 is connected to an operation panel 12 disposed on the upper surface or the back surface of the main body of the display device 1. The operation panel 12 includes a plurality of operation elements, generates operation signals corresponding to the operations of these operation elements, and outputs them to the control device 10.

The image processing apparatus 5 according to the present embodiment includes an input interface (I / F) 51 to which the above image data is input, and a plurality of processing units that sequentially process the images input to the input interface 51. The input image is processed according to the control of the apparatus 10, and the processed image data is written in the frame memory 61. The drive control unit 62 reads out the processed image data from the frame memory 61 under the control of the control device 10 and drives the liquid crystal light valve 3 to display an image.
The processing unit included in the image processing apparatus 5 includes an input clip unit 52 (cutout processing unit) that clips an image input to the input interface 51, and a horizontal resolution conversion that performs horizontal resolution conversion of an image processed by the input clip unit 52. A unit 53 (horizontal resolution conversion unit), an output horizontal clip unit 54 (horizontal clip unit) that performs processing for clipping an image converted by the horizontal resolution conversion unit 53, and an image processed by the output horizontal clip unit 54 temporarily. The line memory 55 (storage means) stored in the image data, the vertical resolution conversion unit 56 (vertical resolution conversion means) for converting the vertical resolution of the image stored in the line memory 55, and the image converted by the vertical resolution conversion unit 56. And an output vertical clip unit 57 (vertical clip means) for clipping. The enlargement processing means of the present invention includes the horizontal resolution conversion unit 53, the output horizontal clip unit 54, the line memory 55, the vertical resolution conversion unit 56, and the output vertical clip unit 57.

FIG. 2 is a flowchart showing the operation of the display device 1, and particularly shows the operation when executing the enlargement / reduction function for displaying the input image in an enlarged or reduced manner.
When executing the enlargement / reduction function, since the zoom magnification (enlargement ratio) is designated by operating the operation panel 12, the control device 10 acquires the designated zoom magnification (step S11). Subsequently, the control device 10 calculates a resolution for clipping from the input image based on the output resolution and the zoom magnification (step S12), and performs image enlargement / reduction processing for cutting out and enlarging the image with the calculated resolution from the input image. It is executed by the image processing device 5 (step S13). As a result, the input image is enlarged or reduced at the designated zoom magnification and displayed on the screen SC.

The operation of the image processing device 5 will be described in detail.
FIG. 3 is a diagram illustrating an example of an image enlargement / reduction process executed by the image processing apparatus 5. 3, (A) shows an input image, (B) shows a clip image (cut image) cut out from the input image, (C) shows an image after horizontal resolution conversion, and (D) shows An image after output horizontal clipping clipped in the horizontal direction is shown, (E) shows an image after vertical resolution conversion, and (F) shows an image after output vertical clipping clipped in the vertical direction.
In the following description, as shown in FIG. 3A, a case where the input image 101 of 720 × 480 is enlarged at a zoom magnification of 2 and displayed as an output image of output resolution 1024 × 768 will be described as an example. To do.
The input clip unit 52 clips a part of the input image 101 input to the input interface 51 in accordance with the cut-out resolution obtained from the output resolution and the zoom magnification, and the clip image 102 shown in FIG. Generate. In the input image 101, the portion clipped by the input clip unit 52 is arbitrary, and can be designated by operating the operation panel 12, for example.

Next, the horizontal resolution conversion unit 53 executes horizontal resolution conversion processing for enlarging the horizontal resolution of the clip image 102 output from the input clip unit 52 in accordance with the output resolution. In this example, the output resolution in the horizontal direction is 1024 dots, but the horizontal resolution converter 53 enlarges the resolution to 1028 dots, which is larger than the output resolution. For this reason, as shown in FIG. 3C, the horizontal resolution-converted image 103 output by the horizontal resolution conversion unit 53 is an image of 1028 × 384 dots in which the horizontal resolution is 4 dots higher than the output resolution. Yes.
Subsequently, the output horizontal clip unit 54 extracts a portion corresponding to the output resolution, that is, an output horizontal clipped image 104 of 1024 × 384 dots, from the horizontal resolution converted image 103 output by the horizontal resolution converting unit 53, The output horizontal clipped image 104 is written into the line memory 55. The output horizontal clip unit 54, for example, cuts off the 2-dot external area 103A located at both ends of the image 103 after the horizontal resolution conversion.

The display device 1 of the present embodiment improves the image quality by generating the horizontal resolution-converted image 103 having horizontal 1028 dots larger than the output resolution and then extracting only the portion of 1024 dots in the horizontal direction. Yes. This point will be described in detail.
As a technique for performing resolution conversion, a known method such as a linear interpolation method, a projection method, or a nearest neighbor method can be used. Here, a case where a linear interpolation method is used will be described as an example.

4A and 4B are diagrams illustrating a general resolution conversion by the linear interpolation method. FIG. 4A illustrates an arrangement of pixels of an image before conversion, and FIG. 4B illustrates an arrangement of pixels of an image after conversion. .
5A and 5B are diagrams showing the state of resolution conversion according to the present embodiment, in which FIG. 5A shows the pixel arrangement in the image before conversion, and FIG. 5B shows the pixel arrangement in the image after conversion. , (C) shows the pixel arrangement in the clipped image. 4 and 5 exemplify a case where processing for increasing the resolution of an image to be processed is performed.
When an image having 512 dots in the horizontal direction is enlarged to 1024 dots, insufficient pixel data is generated by generating one pixel data from pixel data of a plurality of pixels by interpolation calculation. For example, as shown in FIGS. 4A and 4B, a pixel B-1 is generated based on the pixel data of the first pixels A-1 and A-2 before conversion, and the pixels A-1 to A-3 are generated. Pixel B-2 is generated. Similarly, pixel data of each pixel after conversion is generated from three pixels including the pixel before conversion at the same position and the pixels on both sides thereof.
However, in this method, only the pixel B-1 and the pixel B-1024 located at the ends have only two corresponding positions and two neighboring pixels. Since the pixel B-1 and the pixel B-1024 located at this end are generated in the same manner as the other pixels, the pixel A-0 and the pixel A-512 before the pixel A-1 that does not actually exist are usually present. The subsequent pixel A-513 is virtually generated, and the pixel B-1 and the pixel B-1024 are generated using the virtual pixel data. The pixel data of the pixel A-0 and the pixel A-513 is, for example, a copy of the pixel A-1 and the pixel A-512 or pixel data “0” (both RGB colors have a luminance of 0, that is, black). For this reason, the pixel data of the pixel B-1 and the pixel B-1024 becomes an unnatural color compared to the other pixels or darker than the other pixels.

On the other hand, in the present embodiment, an extra pixel is generated by resolution conversion, and the image quality is improved by discarding the pixel.
From the pre-conversion image data of 512 dots shown in FIG. 5A, image data of 1028 dots is generated as shown in FIG. Since the pixel B-1 and the pixel B-1028 located at the end are generated from the pixel data of the three pixels including the virtual pixel as described above, the colors are unnatural compared to other pixels, It may be dark. Here, the image processing apparatus 5 uses the output horizontal clip unit 54 to remove the extra 4 dots from the converted data of 1028 dots shown in FIG. Specifically, the two dots of the first pixels B-1 and B-2 and the two dots of the last pixels B-1027 and 1028 are removed. As a result, pixels that may not be of better quality than other pixels are removed, and pixels B-3 to 1026 are output as the output horizontal clipped image 104. The above interpolation calculation can also obtain pixel data of one pixel from more than three pixels. In this case, not only the converted pixels B-1 and 1028 but also more pixels are affected by virtual pixels. In order to cope with such a case, in the example shown in FIG. 5B, the top and the end are deleted by two dots. Of course, it is possible for the output horizontal clip unit 54 to delete more pixels by converting the horizontal resolution conversion unit 53 to a higher resolution. Further, the pixels to be deleted by the output horizontal clip unit 54 (the external region 103A in FIG. 3C) do not need to be uniform at the beginning and the end.

The horizontal resolution conversion unit 53 acquires the clip image 102 in units of horizontal lines, performs resolution conversion processing in units of lines, and outputs the processed horizontal resolution converted image 103 in units of lines. More specifically, the horizontal resolution conversion unit 53 acquires data for one line of the clip image 102 in order from the first dot, and at the time when the first pixels A-1 and A-2 are acquired, the top of the image after conversion. Pixel B-1 is generated. Hereinafter, the horizontal resolution conversion unit 53 generates pixel data of the image 103 after the horizontal resolution conversion while acquiring the data of the processing target line of the clip image 102, and outputs the image 103 after the horizontal resolution conversion in order from the first dot. In the processing of the horizontal resolution conversion unit 53, it is not necessary to store the clip image 102 and the horizontal resolution converted image 103 in the memory all in one line. Then, the horizontal resolution conversion unit 53 sequentially outputs one line of image data of the horizontal resolution converted image 103 from the first dot. The output horizontal clip unit 54 reads and discards the image data of the first two dots and the last two dots among the data of one line output from the first dot by the horizontal resolution conversion unit 53. By this simple processing, the output horizontal clipped image 104 excluding the external area 103A can be extracted. Then, the output horizontal clip unit 54 writes the remaining data obtained by discarding the head and tail of one line of the image 103 after horizontal resolution conversion to the line memory 55 in order from the head dot.
Therefore, in the processing executed by the horizontal resolution conversion unit 53 and the output horizontal clip unit 54, it is necessary to store the entire data of one line of the clip image 102, the horizontal resolution converted image 103, and the output horizontal clipped image 104 in the memory. Therefore, the required memory capacity can be reduced and the processing speed can be increased.

  The vertical resolution conversion unit 56 reads the output horizontal clipped image 104 from the line memory 55 line by line in the vertical direction, performs resolution conversion, and generates a vertical resolution converted image 105 shown in FIG. The processing method in which the vertical resolution conversion unit 56 performs resolution conversion is, for example, the interpolation calculation method described with reference to FIG. The vertical resolution conversion unit 56 outputs the 772 dot vertical resolution converted image 105 that is larger than the required output resolution (here, 768 dots). The output vertical clip unit 57 removes the external region 105A of the first and last two dots in the vertical direction of the vertical resolution converted image 105 output by the vertical resolution conversion unit 56, and outputs an output vertical clip unit image of 768 dots in length. 106 is generated. The output vertical clip portion image 106 conforms to the resolution of the output image displayed on the liquid crystal light valve 3. The output vertical clip unit 57 writes the output vertical clip unit image 106 after clipping into the frame memory 61, and the drive control unit 62 reads out the output vertical clip unit image 106 written into the frame memory 61, and the liquid crystal light valve 3. To draw.

Here, the vertical resolution conversion unit 56 acquires the output horizontal clipped image 104 stored in the line memory 55 in units of lines in the vertical direction, performs resolution conversion line by line, and processes the processed vertical resolution converted image 105. Are output in line units. More specifically, the vertical resolution conversion unit 56 sequentially acquires data for one line of the output horizontal clipped image 104 in the vertical direction from the first dot, and at the time when the first several pixels are acquired, the top of the converted image is acquired. Are generated. Hereinafter, the vertical resolution conversion unit 56 generates pixel data after conversion while acquiring data of the processing target line of the output horizontal clipped image 104, and outputs the vertical resolution converted image 105 in order from the first dot. Further, the output vertical clip unit 57 removes the external area 105A by discarding the beginning and end of the data of the vertical resolution converted image 105 output by the vertical resolution conversion unit 56 in order from the beginning, and outputs the output vertical clip unit. An image 106 is generated, and the output vertical clip portion image 106 is written in the frame memory 61 in order from the first dot.
Accordingly, in the processing executed by the vertical resolution conversion unit 56 and the output vertical clip unit 57, it is not necessary to store the entire data for one line of the image 105 after the vertical resolution conversion in the memory. Processing speed can be increased.

  As described above, the display device 1 according to the embodiment to which the present invention is applied has the image processing device 5 that generates an output image having a predetermined output resolution from the input image, and has a cut-out resolution from the input image. The input clip unit 52 that cuts out the clip image 102, and the resolution conversion of the clip image 102, the horizontal resolution converted image 103 and the vertical resolution converted image 105 are generated as an enlarged image having a resolution higher than the output resolution, and generated. Since an output image having a predetermined resolution is generated by clipping a portion corresponding to the output resolution from these enlarged images, a high-quality output image obtained by enlarging the input image by resolution conversion can be generated. That is, after obtaining an enlarged image with a resolution higher than the output resolution, a portion corresponding to the output resolution is extracted from the enlarged image to generate an output image. Therefore, the output image has a peripheral portion of the image after resolution conversion. The image is removed. For this reason, since the low-quality portion generated at the peripheral portion during resolution conversion is removed, the extracted output image can be expected to have high image quality up to the peripheral portion, so that the image quality of the output image is improved. be able to. Further, the process of extracting a part from the image after resolution conversion can be executed without storing the converted high-resolution image in the memory, and can be realized without increasing the necessary memory capacity and load.

The image processing apparatus 5 also converts a horizontal resolution of the clip image 102 clipped by the input clip unit 52 and outputs the converted data for each horizontal line, and a horizontal resolution conversion The portion corresponding to the output resolution is clipped from the line-by-line data output by the unit 53, and the horizontal clip part for outputting the horizontal conversion image data for each line, and the horizontal conversion image data extracted by the horizontal clip part A line memory 55 that sequentially stores, a vertical resolution conversion unit 56 that converts the vertical resolution of the horizontally converted image stored in the line memory 55, and outputs the converted data for each vertical line, and a vertical resolution conversion unit The portion corresponding to the output resolution is clipped from the line-by-line data output by 56, and the output image data is line-by-line. It includes an output vertical clip portion 57 to force the.
The horizontal resolution conversion unit 53 converts the horizontal resolution of the image cut out by the input clip unit 52 and outputs the converted data for each horizontal line. The output horizontal clip unit 54 includes the horizontal resolution conversion unit 53. A portion corresponding to the output resolution is extracted from the data output for each line. As described above, since the resolution conversion in the horizontal direction and the extraction to the data corresponding to the output resolution are executed for each line, it is necessary to store the image in the memory during the processing of the horizontal resolution conversion unit 53 and the output horizontal clip unit 54. Absent. Therefore, the required memory capacity can be suppressed and the processing speed can be increased. The vertical resolution conversion unit 56 reads the image data stored in the line memory 55 for each line in the vertical direction, converts the vertical resolution, and outputs an output vertical clip unit having a higher vertical resolution than the output resolution. The image 106 is output, and the output vertical clip unit 57 extracts a portion corresponding to the output resolution from the output vertical clip unit image 106. Since this vertical resolution processing is performed for each vertical line, there is no need to store image data in the memory during this processing, reducing memory usage and further speeding up the processing. Can be planned.

  The horizontal resolution conversion unit 53 converts the horizontal resolution of the clip image 102 clipped by the input clip unit 52 to a higher resolution than the output resolution. For this reason, an image having a higher resolution than the output resolution can be easily obtained from the clip image 102 having a required resolution obtained from the output resolution and the zoom magnification, and an output image having a high image quality can be obtained. Further, the vertical resolution conversion unit 56 converts the vertical resolution of the output horizontal clipped image 104 stored in the line memory 55 to a higher resolution than the output resolution. For this reason, an image having a higher resolution than the output resolution can be easily obtained from the clip image 102 having a required resolution obtained from the output resolution and the zoom magnification, and an output image having a high image quality can be obtained.

  Further, since the input clip unit 52 generates the clip image 102 by clipping the input image 101 in accordance with the size determined from the output resolution and the zoom magnification, the capacity of the memory for storing the clip image 102 is minimized. There is an advantage that it can be done.

  In the above embodiment, the input clip unit 52 generates a clip image 102 that matches the size determined from the output resolution and zoom magnification, and the clip image 102 is generated by the horizontal resolution conversion unit 53 and the vertical resolution conversion unit 56. However, the present invention is not limited to this, and a method of increasing the size to be clipped by the input clip unit 52 is also useful. Hereinafter, this case will be described as a modified example.

[Modification]
FIG. 6 is a diagram illustrating processing for enlarging an image according to the modification. In FIG. 6, (A) is an input image, (B) is a clip image cut out from the input image, (C) is an image after horizontal resolution conversion, and (D) is an image after output horizontal clipping clipped in the horizontal direction. , (E) shows an image after vertical resolution conversion, and (F) shows an output vertical clipped image clipped in the vertical direction. In this modification, the output image size is 1024 × 768 dots and the zoom magnification is double.

In the modification shown in FIG. 6, the input clip unit 52 clips the input image 101 to generate a larger clip image 112. The clip image 112 is larger than the minimum size of 512 × 384 dots required when the output image is 1024 × 768 dots and the zoom magnification is two times, and has an extra external area 112A vertically and horizontally.
The horizontal resolution conversion unit 53 converts the resolution of the clip image 112 including the external area 112A, and outputs a horizontal resolution converted image 113. The horizontal resolution of the image 113 after the horizontal resolution conversion is 1028 dots, which is larger than the 1024 dots required as an output image. Since the output horizontal clip unit 54 clips the horizontal resolution converted image 113, the horizontal region of the external area 113A of the horizontal resolution converted image 113 is removed, and an output suitable for the horizontal resolution of the output image is removed. A horizontal clipped image 114 is generated.

  When the clip image 112 is interpolated to generate the image 113 after the horizontal resolution conversion, since there is pixel data outside the originally required range, the portion of the image after the horizontal resolution conversion 113 excluding the external region 113A is present. The pixel data is data obtained from the pixel data of the existing pixels, and there is no possibility that the color is unnatural compared to other pixels or darker than other pixels. Therefore, by removing the external region 113A from the horizontal resolution converted image 113, a high-quality output image can be obtained in the horizontal direction.

Further, the vertical resolution conversion unit 56 converts the resolution of the output horizontal clipped image 114 having the external region 114A in the vertical direction, and generates the vertical resolution converted image 115 having the external region 115A. When the post-output horizontal clip image 114 is interpolated to generate the post-vertical resolution converted image 115, the interpolation calculation is performed using the external area 114A of the post-output horizontal clip post-image 114. The pixel data excluding the external region 115A is data obtained from the pixel data of the existing pixels. For this reason, there is no possibility that the color is unnatural compared to other pixels or darker than other pixels. Accordingly, by removing the external region 115A from the vertical resolution converted image 115, an output vertical clip portion image 116 that is a high-quality output image can be obtained.
According to the modification shown in FIG. 6, the input clip unit 52 generates a clip image 112 including more pixels than the resolution of the necessary input image obtained from the output resolution and the zoom magnification. By processing, it is possible to easily generate a high-resolution image and improve the image quality of the output image including the periphery.

  The above-described embodiment is merely an example of a specific mode to which the present invention is applied, and the present invention is not limited. The present invention can be applied as a mode different from the above-described embodiment. For example, the horizontal resolution conversion unit 53 and the vertical resolution conversion unit 56 included in the display device 1 of the embodiment have been described as performing resolution conversion by interpolation calculation, but the present invention is not limited to this. The resolution conversion may be performed by a method such as a projection method or a nearest neighbor method. Also in this case, since the image quality tends to be deteriorated at the peripheral portion of the image after resolution conversion, it is useful to obtain an output image by performing clipping as in the present application. In the above embodiment, the case where the zoom magnification is set to 2 has been described as an example. However, the present invention is not limited to this, and the present invention is applied at an arbitrary zoom magnification of 1 or more. The present invention is also applicable when the zoom magnification is less than 1, that is, when the input image is reduced and displayed. In the above embodiment, the case where a still image is displayed has been described as an example. However, the present invention can of course be applied to a case where a moving image is displayed. In this case, each frame constituting the moving image is displayed. May be processed as described above.

Further, for example, the display device of the present invention is not limited to a projector that projects an image on the screen SC, and an image is displayed on a liquid crystal monitor or a liquid crystal television that displays an image / video on a liquid crystal display panel, or a plasma display panel (PDP). / Monitor device or television receiver for displaying images, monitor device or television receiver for displaying images / videos on an organic EL display panel called OLED (Organic light-emitting diode), OEL (Organic Electro-Luminescence), etc. Various display devices such as a self-luminous display device are also included in the image display device of the present invention. In this case, a liquid crystal display panel, a plasma display panel, and an organic EL display panel correspond to the display means. Moreover, each function part of the display apparatus 1 shown in FIG. 1 shows the functional structure of a display apparatus, and a specific mounting form is not restrict | limited in particular. That is, it is not always necessary to mount hardware corresponding to each function unit individually, and it is of course possible to adopt a configuration in which the functions of a plurality of function units are realized by one processor executing a program.
Further, in the above-described embodiment, the processing for processing the input image according to the zoom magnification and the output resolution has been described as a configuration executed by the image processing device 5 under the control of the control device 10 included in the display device 1. The invention is not limited to this, and the series of processing may be performed by an image supply device such as a personal computer externally connected to the display device 1. In this case, the image supply device can include the functions of the image processing device 5 and the control device 10 included in the display device 1. The present invention can also be realized as a program executed by such an apparatus. In these configurations, the display device 1 only needs to project an image input from the image supply device onto the screen SC. Further, the display device 1 includes the dimming element 120 according to the dimming rate input from the image supply device. It is more preferable if it has a function to adjust.
In the above-described embodiment, an example in which a liquid crystal light valve using three transmissive or reflective liquid crystal panels corresponding to each color of RGB as display means for modulating light emitted from a light source has been described. However, the present invention is not limited to this, for example, a system using one liquid crystal panel and a color wheel, a system using three digital mirror devices (DMD), a single digital mirror device and a color. It is also possible to adopt a DMD system combined with a wheel. Here, when only one liquid crystal panel or DMD is used, a member corresponding to a composite optical system such as a cross dichroic prism is unnecessary. In addition to the liquid crystal panel and the DMD, any configuration that can modulate the light emitted from the light source can be used without any problem.

  DESCRIPTION OF SYMBOLS 1 ... Display apparatus, 2 ... Light source device, 3 ... Liquid crystal light valve (display means), 4 ... Projection optical system, 5 ... Image processing apparatus, 10 ... Control apparatus, 52 ... Input clip part (cutout process means), 53 ... horizontal resolution converter (horizontal resolution converter), 54 ... output horizontal clip part (horizontal clip means), 55 ... line memory (storage means), 56 ... vertical resolution converter (vertical resolution converter), 57 ... output vertical Clip part (vertical clip means), 61 ... frame memory, 62 ... drive control part, SC ... screen.

Claims (7)

An image processing apparatus that generates an output image having a predetermined output resolution from an input image,
A cutting processing means for cutting out a cut image having a cut resolution from the input image;
Enlargement processing for generating the output image by converting the resolution of the cut-out image, generating an enlarged image having a higher resolution than the output resolution, and extracting a portion corresponding to the output resolution from the generated enlarged image Means,
An image processing apparatus comprising: The enlargement processing means includes
Horizontal resolution conversion means for converting the horizontal resolution of the cut-out image and outputting the converted data for each horizontal line;
Horizontal clipping means for clipping a portion corresponding to the output resolution from the data for each line output by the horizontal resolution conversion means, and for outputting data of the horizontal conversion image for each line;
Storage means for sequentially storing the data of the horizontally converted image clipped by the horizontal clip means;
Vertical resolution conversion means for converting the resolution in the vertical direction of the horizontal conversion image stored in the storage means and outputting the converted data for each vertical line;
Vertical clipping means for clipping a portion corresponding to the output resolution from the data for each line output by the vertical resolution conversion means, and for outputting the output image data for each line;
The image processing apparatus according to claim 1, further comprising:   The image processing apparatus according to claim 2, wherein the horizontal resolution conversion unit included in the enlargement processing unit converts a horizontal resolution of input image data to a higher resolution than the output resolution.   The vertical resolution conversion means included in the enlargement processing means converts the vertical resolution of the horizontally converted image stored in the storage means to a higher resolution than the output resolution. The image processing apparatus described.   The cut-out processing unit cuts out an area including more pixels than the necessary resolution of the input image obtained from the output resolution and the enlargement ratio from the input image. Image processing device. An image processing method for generating an output image having a predetermined output resolution from an input image,
Cut out a cutout image having a cutout resolution from the input image,
The resolution of the clipped image is converted to generate an enlarged image having a higher resolution than the output resolution,
Generating the output image by extracting a portion corresponding to the output resolution from the generated enlarged image;
An image processing method characterized by the above. A display device that generates an output image having a predetermined output resolution from an input image and displays the generated output image,
A cutting processing means for cutting out a cut image having a cut resolution from the input image;
Enlargement processing for generating the output image by converting the resolution of the cut-out image, generating an enlarged image having a higher resolution than the output resolution, and extracting a portion corresponding to the output resolution from the generated enlarged image Means,
Display means for displaying the output image generated by the enlargement processing means;
A display device comprising:

Images