Twice as many pixels can fit into the same space. If you decrease the physical size of an image by half, the resolution doubles. When the pixel dimensions are constant and you decrease the physical size of an image, the resolution increases correspondingly. For example, if you set the physical size, Photoshop changes the resolution. To keep the total amount of pixels in the image the same, Photoshop compensates for the value you set by increasing or decreasing the other value. When you resize without resampling, you can set either the physical size or the resolution of the image. The only two values you can change are the physical size (Width and Height in Document Size) or the resolution (pixels/inch). When you deselect, or turn off, Resample, the pixel dimension fields are not available. No data is added to or removed from the image. Resizing without resampling changes the image's physical size without changing the pixel dimensions in the image. When you resize an image and do not resample it, you change the image's size without changing the amount of data in that image. Degraded images can look blurry, jagged, or blocky. For example, if the file size changes from 250 KB to 500 KB, you add twice as much data to the image, which can degrade it. Then, you can use the file size information to understand how much data is removed or added to your image when you resample it. Note the file size value before you change the other values in the dialog box. You cannot set the file size it changes when you change the total amount of data in the image (the pixel dimensions).
Changing the physical size affects the pixel dimensions but not the resolution.Changing the resolution affects the pixel dimensions but not the physical size.Changing the pixel dimensions affects the physical size but not the resolution.The pixel dimensions are always affected. If you change one value, you affect the others. When you turn on Resample, you can change any of the values in the Image Size dialog: pixel dimensions, physical size, or resolution. However, if you resample your images, do so only once. You could get the results you need by resizing your image without resampling. You get the best results working with images you bring into Photoshop in the proper resolution for the output you want. This procedure is more complex than guessing which pixels to remove when you downsample. That's because upsampling requires that Photoshop guess which pixels to add. Removal of data from an image is typically preferable to the addition of data. Whenever data is removed from or added to the image, the image quality degrades to some extent. When you decrease the number of pixels ( downsampling), the application removes data. When you increase the number of pixels in this part of the dialog box ( upsampling), the application adds data to the image. Resampling changes the total number of pixels in the image, which are displayed as Width and Height in pixels in the Image Size dialog. To resample your image, ensure that Resample is selected at the bottom of the Image Size dialog. When you resize and resample an image, you change the amount of data in that file. Pressing these keys changes the Cancel button to a Reset button.
Tip:To reset the Image Size dialog to its original state, press Alt (Windows) or Option (macOS). You may have to do some extra work, such as using the Unsharp Mask filter to sharpen your image, to compensate for the resampling. When you resample, the image quality can degrade to some extent. Or, you can maintain the same amount of data in the image ( resizing without resampling). You can increase or decrease the amount of data in the image ( resampling). The Image Size dialog allows you to resize your images in two ways. Pixel dimensions = physical size / resolution.Resolution = physical size / pixel dimensions.Physical size = resolution x pixel dimensions.Photoshop calculates the physical size, resolution, and pixel dimensions of an image as follows: Image resolution when printed: This value appears in pixels per inch or pixels per centimeter.Document size: Physical size of the image when printed, including a width and height.Image size when it's open in Photoshop: This value appears at the top of the dialog box.Pixel dimensions: The width and height of the image.When you use the Image Size dialog to resize your images (choose Image > Image Size), four aspects of your image can change:
0 kommentar(er)
