Image processing 7- image enhancement

Image processing series ：

The image processing 1- Classical spatial domain enhancement —— Grayscale mapping

The image processing 2- Classical spatial domain enhancement —— Histogram equalization

The image processing 3- Classical spatial domain enhancement —— Spatial filtering

The image processing 4- Fourier transform of the image

The image processing 5- Image noise

The image processing 6- Otsu image threshold segmentation

In this paper, the source code See my resources , Free download .

  Image enhancement

（1） Download three pictures on the Internet

（2） Preprocess the picture ;

（3） Export the preprocessed picture .

1. Import package

       Pictured 1.1, Import the package to use .

chart 1.1 Import the package you need to use

2. Images are downloaded

       Pictured 1.2, Use this code to automatically download pictures , Download photos from Bing pictures specific search results .

chart 1.2 Image automatic crawling code

3. Various pretreatment

       This section attempts to use a variety of image enhancement methods to process images , And show the effect .

a. Read the picture

       Use as shown in the figure 1.3 Code for image reading , And display .

  chart 1.3 Picture reading and display

b. Random scaling

       Use the figure 1.4 Code for image scaling , And display .

chart 1.4 Picture scaling and display

c. Random position clipping and center position clipping

       Use the figure 1.5 Code for random position clipping and display .

chart 1.5 Random position clipping

       Use the figure 1.6 Code for the central position of the crop , And display .

chart 1.6 Center position clipping

d. Random horizontal and vertical flips

       Use the figure 1.7 Code to flip horizontally , And display .

chart 1.7 Random horizontal flip

       Use the figure 1.8 Code to flip vertically , And display .

chart 1.8 Random vertical flip

e. Random angle flip

       Use the figure 1.9 Code for random angle flip and display .

chart 1.9 Random angle flip

f. chroma 、 brightness 、 saturation 、 Contrast 、 Gray change

       Use the figure 1.10 Code to change chromaticity and display .

chart 1.10  Chromaticity transformation

       Use the figure 1.11 Code to change the brightness and display .

chart 1.11  Brightness conversion

       Use the figure 1.12 Code for saturation transformation , And display .

chart 1.12 Saturation change

       Use the figure 1.13 Code for contrast change , And display .

chart 1.13 Contrast change

       Use as shown in the figure 1.14 Code for grayscale changes , And display .

chart 1.14 Gray change

g. expand

       Use the figure 1.15 Code to extend , And display .

chart 1.15 expand

h. Use PiPeLine change

       Use the figure 1.16 The series of operations you want to perform , Encapsulate into a compose, Combine and change the pictures , And display .

chart 1.16 Use PiPeLine change

4. Automatic processing of batch images

       Combined with the above attempts , We can use graphs 1.17 The code first converts a series of random transformations , Package into a PiPeLine

chart 1.17 Batch image enhancement automatic preprocessing code

in , Then read the photos in the picture folder in batches , Batch processing of each photo , And save it to a folder. The effect is shown in Figure 1.18.

chart 1.18 Automated image enhancement