download a picture App and modify it.

modify it with ps after downloading. No, if you send it out, it's plagiarism.

: use PS to open the finished poster.

be clear about what you want to modify, and have your own ideas.

copying the background layer will make the following steps easier.

use the cutting tool to cut out the image area you want. If you want to select an area in the whole picture, you can use the cutting tool to cut it. Select the background, click Image-Adjust-Hue/Saturation, adjust the background color, select the icon in the upper right corner, delete the selection, and fill it with a paint bucket as the background color.

the overall color sense of a picture is very important. Make the whole page look simple and generous. Fewer colors will make the picture look comfortable.

adjust the layout of the picture according to your own ideas. Swap the upper and lower areas of the picture.

adjust to your satisfaction. Basic adjustment completed.