1, image-image size, check the pixels of the background image, as shown in the following figure:
2. In the image to be copied, select the rectangular marquee tool, select the style in the tool properties, select the fixed size, and fill in the specific data in the height and width, as shown in the following figure:
3. Paste in the document to be pasted. Because the copied selection and background have the same pixel size, there is no need to resize.