How do you enter image dimensions in photoshop?

Choose Image> Image Size.Do any of the following to modify the image preview :    To change the size of the preview window , drag the corner of the screen and the Image Size is size.    To view a different area of the image , drag within the preview.    To change the larger preview, click with the pressure on down Ctrl ( Windows) or Command ( Mac OS) as in the preview image to increase the magnification. -Click on the down Alt ( Windows) or Option ( Mac OS) as to minimize magnification. After clicking , show the percentage to enlarge briefly near the bottom of the preview image.To change the unit of measurement to pixels after , click the triangle to the side Dimensions and select from the list.To maintain the original ratio to measure the width to height , make sure you enable the Constrain Proportions. If you want to change the scale of the width and height separately from the other , click the Constrain Proportions icon to abolish the link between them .Note :You can change the unit of measurement of the width and height to choose from the menus to the right of the text boxes Width and Height.Do one of the following :    To change the size of the image or accuracy and allow adjusting the total number of pixels in a manner disproportionate , be sure to select the option and select Resample method involve , if necessary , from the list of Resample.    To change the size of the image or accuracy without changing the total number of pixels in the image , you must deselect the option Resample.(Optional) from the list of Fit To:    Select a preset to change the image size.    Select Auto Resolution to resize the image to a certain printed output . In the dialog box Auto Resolution, select a value and select the Screen Quality. You can change the unit of measure to choose from the menu to the right of the text box Screen.Enter values ​​in the boxes Width and Height. Enter values ​​for the different measurement unit , select from the menu next to the text boxes Width and Height.Shows the file size of the image at the top of the new screen Image Size, and shows him the old file size in parentheses.To change the Resolution, enter a new value . (Optional) You can also choose different measurement units .If your image contains layers of patterns applied to them , select Scale Styles from the gear icon to change the scale effects in the image that has been resized . This option is available only if you select Constrain Proportions.When you are finished setting options , do any of the following things :    Click OK

1-Open an image you need to resize.

2-Produce a duplicate of the file just in case the resized image is not what you intended. Select Image → Duplicate in the menu bar, or just select File → Save As and save the file under a new name.

3-Go to Image → Image Size. At this point, a screen will pop up indicating your image's current size.You'll see two boxes in the Image Size window: Pixel Dimension and Document Size. For the purposes of resizing the image, you only need to worry about the first box, or Pixel Dimension.

4-Type the new dimensions to the Width and Height box. Unless you change the default settings, typing in one dimension for width will automatically adjust the height setting. This is what the small lock icon indicates.

5-To change the locked proportions, simply uncheck the box next to "Constrain Proportions." Once unchecked, you should be able to type in separate values for both the width and the height.

 6-If you'd like to resize an image by a certain percent, click the "percent" option beside the width and height dimensions. Changing from "pixel" to "percent" will allow you to adjust the size in proportion to what it was before.For example, if your file was originally2200 pixels wide and1400 pixels high, choosing50 percent will reduce the file to1100 pixels wide and700 pixels high.

7- Finished.