the image size in matlab now equal the actual size at computer

Question

Abdullah 2017-3-31

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/332918-the-image-size-in-matlab-now-equal-the-actual-size-at-computer

评论： Abdullah 2017-3-31

Hell My issue is when I use imread to any image then i type whos it gives me the image size by Bytes but its not equal to the actual image size at the computer, its always bigger.

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Jan 2017-3-31

编辑：Jan 2017-3-31

Yes, hell you are right. ;-) What exactly is your question?

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

KSSV 2017-3-31

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/332918-the-image-size-in-matlab-now-equal-the-actual-size-at-computer#answer_261179

在 MATLAB Online 中打开

You see when you read the image using imread, what you have in hand is a RGB matrix or binary matrix depending on the image read. The data has the pixel values of the image and these are numbers either in double or uint. When you type whos matlab shows the Bytes size of this matrix. The sizes which you are comparing are obviously different. If you want to get the size of image in matlab...try

info = dir('my image')

info will be a structure, check bytes there. This is the size which you are looking.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 2

Jan 2017-3-31

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/332918-the-image-size-in-matlab-now-equal-the-actual-size-at-computer#answer_261180

编辑：Jan 2017-3-31

Correct. This is the purpose of the whos command. It shows the memory used for storing a variable. This is the number of elements multiplied by the number of bytes per element. For cells this is the number of elements multiplied by the byte size of a pointer.

Therefore the size shown by whos is expected to be larger than the number of elements.

If you want to get the size in pixels, use size. If you want the file size, see KSSV's answer.