A kind of assisted focused method of video camera
Technical field
The present invention relates to field of photography, the assisted focused method of specifically a kind of video camera.
Background technology
Video camera is optical signalling to be changed into the signal of telecommunication and is further converted into digital signal, and digital signal is delivered to
Record on the recording mediums such as videocorder, or the equipment showing is sent to by broadcasting system on monitor.Equipped with
The production of the video camera of the manual focusing lens and during using it is often necessary to lens focusing.In practical operation, people need
One side rotating lens, go to observe object the presenting in camera views that some details are enriched by naked eyes, to judge
Whether camera lens focuses clearly.This type of focusing has two shortcomings, and one is that work efficiency is slow, and two is poor accuracy, and focusing is not
Must be optimal articulation point, this is all that user brings inconvenience.
Content of the invention
It is an object of the invention to provide a kind of assisted focused method of video camera, to solve to propose in above-mentioned background technology
Problem.
For achieving the above object, the following technical scheme of present invention offer:
A kind of assisted focused method of video camera, specifically comprises the following steps that
Step one, sharpness computation unit is filtered with vertical direction from horizontal direction respectively to image, and each contented
To filtering image;
Step 2, all pixels summation to filtering image will obtain the evaluation of estimate of an image definition, and image is clear
The evaluation of estimate of clear degree is superimposed upon on the image of camera acquisition in digital form;
Step 3, operator can observe numerical values recited in focus process, and it is the most clear that numerical value is focused when maximum
Point.
As the further scheme of the present invention: this algorithm includes controlling switch unit, sharpness computation unit and character and folds
Plus unit.
As the further scheme of the present invention: the evaluation of estimate of image definition is by filtering horizontally and vertically
The calculated numerical value of image, is multiplied by a weighted value respectively and then sues for peace.
As the further scheme of the present invention: sharpness computation unit adopts iir band filter.
As the further scheme of the present invention: the evaluation of estimate of image definition is superimposed upon on image character adding unit.
Compared with prior art, the invention has the beneficial effects as follows: the present invention proposes and a kind of calculates the commenting of image definition
It is worth, and it is added on original image so that the operator of video camera can be by observing the size of this numerical value, judgement be
No focusing clearly auxilary focusing method, this auxilary focusing method is simple to operate, and the evaluation of estimate of image definition is objective effectively,
The work load of operator can significantly be mitigated, the focusing work of the operator of video camera equipped with the manual focusing lens can be improved
Make efficiency, and the accuracy focused can be improved, using effect is good.
Brief description
Fig. 1 is the structural representation of the assisted focused method of video camera.
Specific embodiment
With reference to specific embodiment, the technical scheme of this patent is described in more detail.
A kind of assisted focused method of video camera, specifically comprises the following steps that
Step one, sharpness computation unit adopts the iir band filter pair that a frequency response curve is [0.1,0.9]
Image is filtered respectively with vertical direction from horizontal direction, and each obtains filtering image;
Image is horizontally oriented spatial domain or the signal in vertical direction spatial domain in the pixel distribution of horizontal or vertical direction
Sampling.Low frequency part in the signal of spatial domain correspond to the essential information of image, HFS correspond to strong edge in image with
And noise.Filter the edge feature information that the low frequency in the signal of spatial domain [0,0,1] partly can extract image, and calculate definition
Evaluation of estimate, filters the interference that the high frequency in the signal of spatial domain [0.9,1] partly can suppress noise.
Step 2, all pixels summation to every width filtering image will respectively obtain a numerical value.Filter result mixes
By calculated for filtering image horizontally and vertically numerical value, it is multiplied by a weighted value respectively and then sues for peace, obtain
Numerical value just be image definition evaluation of estimate.The definition of the evaluation of estimate energy effective evaluation present image of image definition, number
Value is more big more clear.Operator can quickly judge whether manual focus operations allow by the evaluation of estimate of movement images definition
Video camera reaches the most clearly state.Actually used experience have shown that, excessive numerical value will waste operator's thinking and sentence
The disconnected time, again not, it is to manage most that the definition evaluation of estimate of image is controlled within 5 digits to a too small numerical value accuracy
The state thought, so the definition evaluation of estimate of image will be divided by a steady state value;
The image definition evaluation value obtaining in sharpness computation unit is converted to dot character simultaneously by character adding unit
It is added on image, the evaluation of estimate of image definition is just superimposed upon on the image of camera acquisition in digital form, makes
Operator can on monitor or other equipment real time inspection to the evaluation of estimate of camera review definition, auxiliary hand-operating
Focus process.
Step 3, operator can observe numerical values recited in focus process, and it is the most clear that numerical value is focused when maximum
Point, controlling switch unit is mainly used in controlling the opening and closing of assisted focused function, opens auxiliary only when there being focusing demand
Focusing function, other when closing function, it is to avoid still see the evaluation of estimate of image definition in normal use.
Above the better embodiment of this patent is explained in detail, but this patent is not limited to above-mentioned embodiment party
Formula, in the ken that one skilled in the relevant art possesses, can also be on the premise of without departing from this patent objective
Make a variety of changes.