IMAGE PICKUP DEVICE AND IMAGE SYNTHESIS METHOD THEREOF

• US 20130307922A1
• Filed: 07/30/2012
• Published: 11/21/2013
• Est. Priority Date: 05/17/2012
• Status: Active Grant

• Current Assignee: Altek Corporation
• Original Assignee: Altek Corporation
• Inventors: Chou, Hong-Long, Tseng, Chia-Chun, Wu, Chia-Yu
• Granted Patent: US 8,953,013 B2
• Time in Patent Office: Days
• US Class Current: 348/36
• CPC Class Codes: H04N 23/698 for achieving an enlarged field of view, e.g. panoramic image capture
• CPC Class Codes: H04N 5/2624 for obtaining an image which is composed of whole input images, e.g. splitscreen

Abstract

This invention discloses an image pickup device and an image synthesis method thereof The image pickup device comprises an image-pickup module, an image-synthesis module, a database and a processing module. The image-pickup module captures a plurality of temporary images of a scene. The image-synthesis module extracts a part of each temporary image and combines the parts to form a panorama temporary image, and splits the panorama temporary image into a plurality of zone-areas according to at least one threshold value and a panorama luminosity histogram. The database stores a lookup table for recording a plurality of exposure values. The plurality of the exposure values correspond to luminance values of the zone-areas respectively. The processing module obtains the plurality of exposure values corresponding to the luminance values and obtains a weighting-exposure value by an equation, and controls the image-pickup module to capture the panorama image according to the weighting-exposure value.

Claims

1. An image pickup device for shooting a scene, comprising:

an image-pickup module, arranged for capturing a plurality of temporary images of the scene;

an image-synthesis module, arranged for extracting a part of each of the temporary images, combining the parts of the temporary images to form a panorama temporary image, and splitting the panorama temporary image into a plurality of zone-areas according to at least one threshold value and a panorama luminosity histogram of the panorama temporary image;

a database, arranged for storing a lookup table that records a plurality of exposure values, and the plurality of exposure values corresponding to a luminance value of each the zone-area respectively; and

a processing module, arranged for obtaining the plurality of exposure values corresponding to the luminance values respectively from the database, obtaining a weighting-exposure value by an equation, and controlling the image-pickup module to perform a panorama image capturing process according to the weighting-exposure value;

wherein, the equation is to multiply each of the exposure values by a ratio of the zone-area corresponding to each of the luminance values to the total area and then sum up the products to generate the weighting-exposure value.

2. The image pickup device of claim 1, wherein the image-synthesis module synthesizes the panorama luminosity histogram by a temporary luminosity histogram of each of the temporary images and uses the most densely distributed luminance area of each of the temporary luminosity histograms in the panorama luminosity histogram as the zone-area.

3. The image pickup device of claim 2, wherein the image-synthesis module determines the threshold value according to the quantity of temporary images.

4. The image pickup device of claim 1, wherein the luminance value is an average luminance of the corresponding zone-area, an average value of the maximum luminance and the minimum luminance or a difference of the maximum luminance and the minimum luminance.

5. The image pickup device of claim 1, wherein the image-synthesis module extracts a vertical image at the middle section of each of the temporary images and combines the vertical images to form the panorama temporary image.

6. An image synthesis method for shooting a scene, comprising the steps of:

capturing a plurality of temporary images of the scene by an image-pickup module;

extracting a part of each of the temporary images and combining the parts to form a panorama temporary image by an image-synthesis module;

splitting the panorama temporary image into a plurality of zone-areas according to at least one threshold value and a panorama luminosity histogram of the panorama temporary image by the image-synthesis module;

providing a database to store a lookup table that records a plurality of exposure values, and the plurality of exposure values corresponding to luminance values of each the zone-areas respectively;

using a processing module to obtain the plurality of exposure values corresponding to the luminance values respectively from the database, and multiply each of the exposure value by a ratio of the zone-area corresponding to the luminance value to the total area, and then sum up the products to generate a weighting-exposure value; and

controlling the image-pickup module to perform a panorama image capturing process according to the weighting-exposure value by the processing module.

7. The image synthesis method of claim 6, further comprising the steps of:

synthesizing a temporary luminosity histogram of each of the temporary images to form the panorama luminosity histogram by the image-synthesis module; and

using the most densely distributed luminance area of each of the temporary luminosity histograms in the panorama luminosity histogram as the zone-area.

8. The image synthesis method of claim 7, further comprising the step of:

determining the threshold value according to the quantity of temporary images by the image-synthesis module.

9. The image synthesis method of claim 6, wherein the luminance value is an average luminance of the corresponding zone-area, an average value of the maximum luminance and the minimum luminance or a difference of the maximum luminance and the minimum luminance.

10. The image synthesis method of claim 6, further comprising the steps of:

using the image-synthesis module to extract a vertical image at a middle section of each of the temporary images and combining the vertical images to form the panorama temporary image.

11. An image pickup device, comprising:

an exposure module, arranged for metering a scene to produce a plurality of temporary exposure values;

an image-pickup module, arranged for capturing a plurality of temporary images from the scene according to each of the temporary exposure values;

an image-synthesis module, arranged for extracting a part of each of the temporary images, combining the parts of the temporary images to form a panorama temporary image, and splitting the panorama temporary image into a plurality of zone-areas according to at least one threshold value and a panorama luminosity histogram of the panorama temporary image;

a database, arranged for storing a lookup table that records a plurality of exposure values, and the plurality of exposure values corresponding to luminance values of each the zone-area respectively; and

a processing module, arranged for obtaining the plurality of exposure values corresponding to the luminance values respectively from the database, using an equation to obtain a weighting-exposure value, and controlling the image-pickup module to perform a panorama image capturing process according to the weighting-exposure value;

wherein the equation is to multiply each of the exposure values by a ratio of the zone-area corresponding to each of the luminance values to the total area and then sum up the products to generate the weighting-exposure value.

12. The image pickup device of claim 11, wherein the image-synthesis module synthesizes the panorama luminosity histogram by a temporary luminosity histogram of each of the temporary images and uses the most densely distributed luminance area of each of the temporary luminosity histograms in the panorama luminosity histogram as the zone-area.

13. The image pickup device of claim 12, wherein the image-synthesis module determines the threshold value according to the quantity of temporary images.

14. The image pickup device of claim 11, wherein the luminance value is an average luminance of the corresponding zone-area, an average value of the maximum luminance and the minimum luminance or a difference of the maximum luminance and the minimum luminance.

15. The image pickup device of claim 11, wherein the image-synthesis module extracts a vertical image at the middle section of each of the temporary images and combines the vertical images to form the panorama temporary image.