Monochrome frame detection method

• US 20070256091A1
• Filed: 04/23/2007
• Published: 11/01/2007
• Est. Priority Date: 04/27/2006
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Horiguchi, Takeo
• Application Number:
  US11/789,179
• Publication Number:
  US 20070256091A1
• Time in Patent Office: Days
• US Class Current: 725/22
• CPC Class Codes: G06T 7/80 Analysis of captured images to determine intrinsic or extrinsic camera parameters, i.e. camera calibration

Abstract

According to one embodiment, a monochrome frame detection method includes a first process and second process. The first process includes: (1) reading a video frame; (2) extracting pixel data for each from pixels included in the video frame; (3) calculating an average value of the pixel data; (4) calculating compared values by comparing each of the pixel data and the average value; and (5) determining whether or not the video frame is the monochrome frame based on the compared values. If the video frame is determined to be the monochrome frame the average value is stored as a reference value. In the second process, the calculation of the average value of the (3) is skipped, and the compared values are calculated by comparing each of the pixel data and the stored reference value.

Claims

1. A monochrome frame detection method for determining whether or not a video frame read from a video stream that includes a plurality of video frames is a monochrome frame, the method comprising:

(a) a first process comprising;

(a-1) reading a first video frame included in the video stream;

(a-2) extracting first pixel data for each of first sample pixels selected from first pixels included in the first video frame;

(a-3) calculating an average value of the first pixel data;

(a-4) calculating first compared values for each of the first sample pixels by comparing each of the first pixel data and the average value;

(a-5) determining whether or not the first video frame is the monochrome frame based on the first compared values; and

(a-6) storing the average value as a reference value when the first video frame is determined to be the monochrome frame; and

(b) a second process comprising;

(b-1) reading a second video frame included in the video stream;

(b-2) extracting second pixel data for each of second sample pixels selected from second pixels included in the second video frame;

(b-3) calculating second compared values for each of the second sample pixels by comparing each of the second pixel data and the reference value; and

(b-4) determining whether or not the second video frame is the monochrome frame based on the second compared values.

2. The method according to claim 1, wherein:

the first pixel data comprises first brightness values and first hue values;

the second pixel data comprises second brightness values and second hue values;

the average value comprises an average brightness value and an average hue value;

the reference value comprises a reference brightness value and a reference hue value;

the first compared values comprises first compared brightness values and first compared hue values; and

the second compared values comprises second compared brightness values and second compared hue values.

3. The method according to claim 2, wherein:

each of the first brightness values and the first hue values are extracted for each of the first sample pixels;

each of the second brightness values and the second hue values are extracted for each of the second sample pixels;

each of the average brightness value and the average hue value are calculated for each of the first brightness values and the first hue values;

each of the first compared brightness values and the first compared hue values are calculated by comparing each of the first brightness values and the average brightness value, and each of the first hue values and the average hue value, respectively; and

each of the second compared brightness values and the second compared hue values are calculated by comparing each of the second brightness values and the reference brightness value, and each of the second hue values and the reference hue value, respectively.

4. The method according to claim 1, wherein

the first process is performed for each of a plurality of video frames included in the video stream;

the average value is stored as the reference value only when the average values calculated in each of the first processes are determined to have a same value for a predetermined number of times; and

the second process is performed after the average value is stored as the reference value.

5. A monochrome frame detection method for determining whether or not a video frame read from a video stream that includes a plurality of video frames is a monochrome frame, the method comprising:

(a) an initialization process that is adapted in advance of a detection of the monochrome frame, the initialization process comprising;

(a-1) generating a monochrome frame information file in a storage section that stores the video stream; and

(b) a first detection process that is initially adapted to the video stream, the first detection process comprising;

(b-1) reading a first video frame included in the video stream;

(b-2) extracting first pixel data for each of first sample pixels selected from first pixels included in the first video frame;

(b-3) calculating an average value of the first pixel data;

(b-4) calculating first compared values for each of the sample pixels by comparing each of the first pixel data and the average value;

(b-5) determining the first video frame is the monochrome frame if each of the first compared values is less than a first threshold value;

(b-6) incrementing a counter if the first video frame is determined as the monochrome frame; and

(b-7) storing the average value in the monochrome frame information file as a reference value if the first video frame is determined as the monochrome frame.

6. The method according to claim 5, further comprising:

(c) a second process that is adapted to the video stream if the reference value is stored in the monochrome frame information file, the second process comprising;

(c-1) reading a second video frame included in the video stream;

(c-2) extracting second pixel data for each of second sample pixels selected from second pixels included in the second video frame;

(c-3) calculating second compared values for each of the second sample pixels by comparing each of the pixel data and the reference value; and

(c-4) determining the second video frame is the monochrome frame if each of the second compared values is less than the first threshold value.

7. The method according to claim 6, wherein:

the first pixel data comprises first brightness values and first hue values;

the second pixel data comprises second brightness values and second hue values;

the average value comprises an average brightness value and an average hue value;

the reference value comprises a reference brightness value and a reference hue value;

the first compared values comprises first compared brightness values and first compared hue values; and

the second compared values comprises second compared brightness values and second compared hue values.

8. The method according to claim 7, wherein:

each of the first brightness values and the first hue values are extracted for each of the first sample pixels;

each of the second brightness values and the second hue values are extracted for each of the second sample pixels;

each of the average brightness value and the average hue value are calculated for each of the first brightness values and the first hue values;

each of the first compared brightness values and the first compared hue values are calculated by comparing each of the first brightness values and the average brightness value, and each of the first hue values and the average hue value, respectively; and

each of the second compared brightness values and the second compared hue values are calculated by comparing each of the second brightness values and the reference brightness value, and each of the second hue values and the reference hue value, respectively.