The first time I ran Photoshop CS4, I felt that the interface was simpler and more beautiful. The palette has canceled the seemingly luxurious but actually meaningless shadows of CS3 and replaced them with traditional border lines.
As shown below: 
The menu part has also been redesigned, and the icons are simple and clear. Some commonly used items are placed on the right side of the menu. As shown in the figure below:
Note that you can choose to view new features (WHAT'S NEW IN CS4) in the layout and menu scheme, so that menus with new features will be highlighted. Although it has little practical significance, it is a considerate design.
The new rotation function is for the view, not for the image. Note that the rectangular selection is drawn in the direction of the original view after rotation. The same is true when directly drawing a rectangle and entering text, so it is more appropriately called view rotation.
But there is no direction limit for the Lasso selection tool or brush. In this way, friends who like to use brushes for hand-painting can finally get the function of rotating the canvas similar to Paint.
To our slight regret, the view rotation function is not used in combination with the gripper or zoom tools, but uses a separate shortcut R.
The newly added content-aware transformation (also called smart transformation) tool is more interesting. It can decide how to scale the image by automatically judging the content in the image.
As shown in the figure below, the difference between using content-aware transformation and traditional transformation on an image can be seen from the distribution of trees. The former basically retains the height of the trees, but reduces the sky and the lake.
Although this judgment is not 100% accurate, it is indeed a sign of Photoshop becoming intelligent. After several versions, a similar content-aware lens blur filter is likely to appear, which can automatically determine and blur backgrounds other than people.
Another thing to mention is the newly added image adjustment palette, which is actually a list of adjustment layers in the menu, making it easier for users to use it directly. I think this is a very good improvement and will guide users into a good habit of using adjustment layers. Some commonly used adjustments are listed in the palette. You can also save your own plans in it.
The so-called adjustment layer is a special layer that can make non-destructive color adjustments to the image. It is easy to use and has great flexibility in post-production. This is the way we always advocate to adjust the color of images.
