How do I get RGB-Values

Question

Ismail Güclü 2020-8-23

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/583409-how-do-i-get-rgb-values

回答： Ismail Güclü 2020-8-26

Is it possible to read the rgb-value from a monitor (not image/without screenshot) ? 2. Quesrion: RGB-value from a realtime video ? Thx

2 个评论
显示无隐藏无

KSSV 2020-8-24

Yes you can read video frame by frame as a image/ RGB value. Read this: https://www.mathworks.com/help/matlab/ref/videoreader.html

How you expect to enter RGB values? Manually? Yes you can do but it is tedious isn't it?

Image Analyst 2020-8-24

How did the image get onto the monitor? If it was from MATLAB, then yes, you have the variable. If it was by some other program (Excel, Powerpoint, Photoshop, or whatever) then you'd have to figure out how to do a screen capture first, then examine the saved image.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Walter Roberson 2020-8-24

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/583409-how-do-i-get-rgb-values#answer_484037

Yes? No?

Some graphics cards allow the rendered values to be read out of the buffer. MS Windows in particular tends to restrict this ability because it can be used to bypass some kinds of Digital Rights Management. Arguably this would be a screenshot.
if you added appropriate hardware such as a frame buffer, you could keep a copy of the video stream, especially with digital protocols such as HDMI. Arguably this would be a screenshot.
However the above options only record the graphics sent to the monitor, which is not the same as the monitor will display. Most monitors are not calibrated, and most monitors have built-in gamma adjustment. Hypothetically you might be able to retrieve the gamma table the monitor uses, but the calibration information requires calibration hardware.... and warming up the monitor several days before hand to stabilize the electronics.

Overall I would say that given the contradictions in your requirements, that the answer has to be NO.