BACKGROUND OF THE DISCLOSURE

Technical Field

The present disclosure relates to a calibration to an image, and specifically relates to a calibrating device and a calibrating method of calibrating a real-time image through a dithering process.

Description of Related Art

Generally, images may produce quantization error after being transformed between high resolutions and low resolutions. For users, the images after transformation may appear visual fault(s), which may be seen inconsistently.

For example, if the color depth of an original image is six bits, and the color depth of a displayer used to output images is eight bits, the original image may be upgraded from six bits to eight bits in order to compel with the specification of the displayer. Similarly, if the color depth of the original image is ten bits, and the color depth of the displayer is eight bits, the original image may be downgraded from ten bits to eight bits in order to compel with the specification of the displayer. After the transformation (e.g., upgrading or downgrading), however, the images may produce the aforementioned quantization error.

Please refer toFIG. 1, which is a schematic diagram showing a banding effect. As shown inFIG. 1, when an original image1is processed to increase or decrease the number of bits, a transformed image2may be generated. When looking at the transformed image2through bare eyes, a user may see visual fault(s)21caused in accordance with the banding effect on the transformed image2. In other words, the visual fault(s)21are generated because of the quantization error mentioned above.

In order to smooth the image after being upgraded/downgraded, the upgraded image/downgraded image needs to be further processed.

SUMMARY OF THE DISCLOSURE

The present disclosure is directed to a calibrating device and a calibrating method of calibrating a real-time image through a dithering process, which may add hash value(s) randomly generated to multiple pixel points of the image, so as to solve the quantization error produced of the image after the image is transformed between high resolutions and low resolutions.

In one of the exemplary embodiments, the calibrating device includes:a receiving unit, connected with an image sensor, configured to receive the real-time image from the image sensor and record a time parameter of the real-time image;a storing unit, stored a hash table, wherein the hash table records multiple hash values used to calibrate multiple pixel points of the real-time image;a processor, connected with the receiving unit and the storing unit, comprising:a displacing module, configured to shift the multiple hash values in the hash table in accordance with the time parameter to generate an adjusted hash table; anda computing module, configured to respectively obtain a corresponding one of the hash values from a corresponding grid of the adjusted hash table for each pixel point of the real-time image in accordance with a coordinates of each pixel point, and respectively add the corresponding one of the hash values to a lowest bit of a pixel value of each pixel point to generate a calibrated image; andan outputting unit, connected with the processor, configured to output the calibrated image.

In one of the exemplary embodiments, the calibrating method includes:a) obtaining the real-time image through an image sensor and recording a time parameter of the real-time image;b) reading a hash table, wherein the hash table records multiple hash values used to calibrate multiple pixel points of the real-time image;c) shifting the multiple hash values in the hash table in accordance with the time parameter to generate an adjusted hash table;d) respectively obtaining a corresponding one of the hash values from a corresponding grid of the adjusted hash table respectively for each pixel point of the real-time image in accordance with a coordinates of each pixel point;e) respectively adding the corresponding one of the hash values to a lowest bit of a pixel value of each of the pixel points to generate a calibrated image; andf) outputting the calibrated image.

The disclosed solution may adjust the hash table in accordance with the time parameter of the image, obtain the hash values correspondingly from the adjusted hash table, and calibrate each of the pixel points of the image through each corresponding hash value. Therefore, same pixel point of the sequential images may be prevented from adding same hash value thereto, and the dithering process used by the disclosure may be prevented from a reduced calibrating effect. As a result, the sequential images may be visually smooth in human's eyes.

