Reasons for data format conversion when matlab reads the displayed image

matlab The data read into the image is uint8, and matlab The median value is generally double type （64 position ） operation .

double The data of has a decimal point , and uint8 yes 0－255 The integer of , If you use it directly uint8 Calculation , Rounding error will occur in the calculation process , This error is relatively large in the image data .

uint8 The operation of is just to put a double Remove the part after the decimal point of the type ;

Reference resources ：https://www.pianshen.com/article/1006326703/

1、MATLAB When reading an image, the image data should be converted into double

 

 

imread() Store the grayscale image in a 8 Bit matrix or color map is stored 8 position RGB Matrix

because MATLAB The data read into the image is uint8 Format , however MATLAB Generally used in double type （64） Bit sum operation , So we should turn the image into double type .

2、MATLAB When displaying images, use uint8 Format

imshow() When displaying an image , Need to use uint8 Format , That is to say double Format to uint8

 

3、 summary

MATLAB To save storage space , So reading the image at the beginning is uint8 The format of , namely 8 Bit storage .

But in MATLAB To participate in the operation is to double type , So at this time, you need to convert the image data format double.

When the picture is displayed , If direct imshow（double data format ）, Then it will only be a white picture , because

This is because imshow() When displaying images double Type is to think in 0~1 Within the scope of , Greater than 1 It is always displayed in white , and imshow Show uint8 Type is 0~255 Range . Therefore, the data should be converted into uint8

Reference link ：

https://blog.csdn.net/qq_26093511/article/details/53785298

https://blog.csdn.net/mine_land/article/details/79947734?utm_medium=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-1.channel_param&depth_1-utm_source=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-1.channel_param