Image size and resolution

  1. Photoshop User Guide
  2. Introduction to Photoshop
    1. Dream it. Make it.
    2. What's new in Photoshop
    3. Edit your first photo
    4. Create documents
    5. Photoshop | Common Questions
    6. Photoshop system requirements
    7. Migrate presets, actions, and settings
    8. Get to know Photoshop
  3. Photoshop and Adobe services
    1. Photoshop and Adobe Stock
    2. Creative Cloud Libraries
    3. Creative Cloud Libraries in Photoshop
    4. Grid and guides
    5. Creating actions
    6. Undo and history
    7. Default keyboard shortcuts
    8. Touch capabilities and customizable workspaces
    9. Use the Touch Bar with Photoshop
    10. Use the Capture in-app extension in Photoshop
  4. Photoshop on the iPad
    1. Photoshop on the iPad | Common questions
    2. Get to know the workspace
    3. System requirements | Photoshop on the iPad
    4. Create, open, and export cloud documents
    5. Add photos
    6. Work with layers
    7. Draw and paint with brushes
    8. Make selections and add masks
    9. Retouch your composites
    10. Work with adjustment layers
    11. Adjust the tonality of your composite with Curves
    12. Apply transform operations
    13. Crop and rotate your composites
    14. Rotate, pan, zoom, and reset canvas
    15. Work with Type layers
    16. Work with Photoshop and Lightroom
    17. Get missing fonts in Photoshop on the iPad
    18. Japanese Text in Photoshop on the iPad
    19. Manage app settings
    20. Touch shortcuts and gestures
    21. Keyboard shortcuts
    22. System requirements 1.x | Photoshop on the iPad
    23. System requirements 2.x | Photoshop on the iPad
    24. Edit your image size
    25. Livestream as you create in Photoshop on the iPad
    26. Correct imperfections with the Healing Brush
    27. Create brushes in Capture and use them in Photoshop
  5. Cloud documents
    1. Photoshop cloud documents | Common questions
    2. Photoshop cloud documents | Workflow questions
    3. Manage and work with cloud documents in Photoshop
    4. Upgrade cloud storage for Photoshop
    5. Unable to create or save a cloud document
    6. Solve Photoshop cloud document errors
    7. Collect cloud doc sync logs
    8. Share access and edit your cloud documents
  6. Workspace
    1. Workspace basics
    2. Create documents
    3. Use the Touch Bar with Photoshop
    4. Microsoft Dial support in Photoshop
    5. Tool galleries
    6. Performance preferences
    7. Use tools
    8. Touch gestures
    9. Touch capabilities and customizable workspaces
    10. Technology previews
    11. Metadata and notes
    12. Quickly share your creations
    13. Place Photoshop images in other applications
    14. Preferences
    15. Default keyboard shortcuts
    16. Rulers
    17. Show or hide non-printing Extras
    18. Specify columns for an image
    19. Undo and history
    20. Panels and menus
    21. Place files
    22. Position elements with snapping
    23. Position with the Ruler tool
    24. Presets
    25. Customize keyboard shortcuts
    26. Grid and guides
  7. Web, screen, and app design
    1. Photoshop for design
    2. Artboards
    3. Export files in Photoshop
    4. Device Preview
    5. Copy CSS from layers
    6. Slice web pages
    7. HTML options for slices
    8. Modify slice layout
    9. Work with web graphics
    10. Create web photo galleries
  8. Image and color basics
    1. How to resize images
    2. Work with raster and vector images
    3. Image size and resolution
    4. Acquire images from cameras and scanners
    5. Create, open, and import images
    6. View images
    7. Invalid JPEG Marker error | Opening images
    8. Viewing multiple images
    9. Customize color pickers and swatches
    10. High dynamic range images
    11. Match colors in your image
    12. Convert between color modes
    13. Color modes
    14. Erase parts of an image
    15. Blending modes
    16. Choose colors
    17. Customize indexed color tables
    18. Image information
    19. Distort filters are unavailable
    20. About color
    21. Color and monochrome adjustments using channels
    22. Choose colors in the Color and Swatches panels
    23. Sample
    24. Color mode or Image mode
    25. Color cast
    26. Add a conditional mode change to an action
    27. Add swatches from HTML CSS and SVG
    28. Bit depth and preferences
  9. Layers
    1. Layer basics
    2. Nondestructive editing
    3. Create and manage layers and groups
    4. Select, group, and link layers
    5. Place images into frames
    6. Layer opacity and blending
    7. Mask layers
    8. Apply Smart Filters
    9. Layer comps
    10. Move, stack, and lock layers
    11. Mask layers with vector masks
    12. Manage layers and groups
    13. Layer effects and styles
    14. Edit layer masks
    15. Extract assets
    16. Reveal layers with clipping masks
    17. Generate image assets from layers
    18. Work with Smart Objects
    19. Blending modes
    20. Combine multiple images into a group portrait
    21. Combine images with Auto-Blend Layers
    22. Align and distribute layers
    23. Copy CSS from layers
    24. Load selections from a layer or layer mask's boundaries
    25. Knockout to reveal content from other layers
    26. Layer
    27. Flattening
    28. Composite
    29. Background
  10. Selections
    1. Select and Mask workspace
    2. Make quick selections
    3. Get started with selections
    4. Select with the marquee tools
    5. Select with the lasso tools
    6. Select a color range in an image
    7. Adjust pixel selections
    8. Convert between paths and selection borders
    9. Channel basics
    10. Move, copy, and delete selected pixels
    11. Create a temporary quick mask
    12. Save selections and alpha channel masks
    13. Select the image areas in focus
    14. Duplicate, split, and merge channels
    15. Channel calculations
    16. Selection
    17. Bounding box
  11. Image adjustments
    1. Perspective warp
    2. Reduce camera shake blurring
    3. Healing brush examples
    4. Export color lookup tables
    5. Adjust image sharpness and blur
    6. Understand color adjustments
    7. Apply a Brightness/Contrast adjustment
    8. Adjust shadow and highlight detail
    9. Levels adjustment
    10. Adjust hue and saturation
    11. Adjust vibrance
    12. Adjust color saturation in image areas
    13. Make quick tonal adjustments
    14. Apply special color effects to images
    15. Enhance your image with color balance adjustments
    16. High dynamic range images
    17. View histograms and pixel values
    18. Match colors in your image
    19. How to crop and straighten photos
    20. Convert a color image to black and white
    21. Adjustment and fill layers
    22. Curves adjustment
    23. Blending modes
    24. Target images for press
    25. Adjust color and tone with Levels and Curves eyedroppers
    26. Adjust HDR exposure and toning
    27. Filter
    28. Blur
    29. Dodge or burn image areas
    30. Make selective color adjustments
    31. Replace object colors
  12. Adobe Camera Raw
    1. Camera Raw system requirements
    2. What's new in Camera Raw
    3. Introduction to Camera Raw
    4. Create panoramas
    5. Supported lenses
    6. Vignette, grain, and dehaze effects in Camera Raw
    7. Default keyboard shortcuts
    8. Automatic perspective correction in Camera Raw
    9. How to make non-destructive edits in Camera Raw
    10. Radial Filter in Camera Raw
    11. Manage Camera Raw settings
    12. Open, process, and save images in Camera Raw
    13. Repair images with the Enhanced Spot Removal tool in Camera Raw
    14. Rotate, crop, and adjust images
    15. Adjust color rendering in Camera Raw
    16. Feature summary | Adobe Camera Raw | 2018 releases
    17. New features summary
    18. Process versions in Camera Raw
    19. Make local adjustments in Camera Raw
  13. Image repair and restoration
    1. Remove objects from your photos with Content-Aware Fill
    2. Content-Aware Patch and Move
    3. Retouch and repair photos
    4. Correct image distortion and noise
    5. Basic troubleshooting steps to fix most issues
  14. Image transformations
    1. Transform objects
    2. Adjust crop, rotation, and canvas size
    3. How to crop and straighten photos
    4. Create and edit panoramic images
    5. Warp images, shapes, and paths
    6. Vanishing Point
    7. Use the Liquify filter
    8. Content-aware scaling
    9. Transform images, shapes, and paths
    10. Warp
    11. Transform
    12. Panorama
  15. Drawing and painting
    1. Paint symmetrical patterns
    2. Draw rectangles and modify stroke options
    3. About drawing
    4. Draw and edit shapes
    5. Painting tools
    6. Create and modify brushes
    7. Blending modes
    8. Add color to paths
    9. Edit paths
    10. Paint with the Mixer Brush
    11. Brush presets
    12. Gradients
    13. Fill and stroke selections, layers, and paths
    14. Draw with the Pen tools
    15. Create patterns
    16. Generate a pattern using the Pattern Maker
    17. Manage paths
    18. Manage pattern libraries and presets
    19. Draw or paint with a graphics tablet
    20. Create textured brushes
    21. Add dynamic elements to brushes
    22. Gradient
    23. Paint stylized strokes with the Art History Brush
    24. Paint with a pattern
    25. Sync presets on multiple devices
  16. Text
    1. Work with OpenType SVG fonts
    2. Format characters
    3. Format paragraphs
    4. How to create type effects
    5. Edit text
    6. Line and character spacing
    7. Arabic and Hebrew type
    8. Fonts
    9. Troubleshoot fonts
    10. Asian type
    11. Create type
    12. Text Engine error using Type tool in Photoshop | Windows 8
    13. World-Ready composer for Asian Scripts
    14. How to add and edit text in Photoshop
  17. Video and animation
    1. Video editing in Photoshop
    2. Edit video and animation layers
    3. Video and animation overview
    4. Preview video and animations
    5. Paint frames in video layers
    6. Import video files and image sequences
    7. Create frame animations
    8. Creative Cloud 3D Animation (Preview)
    9. Create timeline animations
    10. Create images for video
  18. Filters and effects
    1. Use the Liquify filter
    2. Use the Blur Gallery
    3. Filter basics
    4. Filter effects reference
    5. Add Lighting Effects
    6. Use the Adaptive Wide Angle filter
    7. Use the Oil Paint filter
    8. Layer effects and styles
    9. Apply specific filters
    10. Smudge image areas
  19. Saving and exporting
    1. Save files in graphics formats
    2. Save your files in Photoshop
    3. File formats
    4. Save and export video and animations
    5. Save PDF files
    6. Digimarc copyright protection
  20. Printing
    1. Print 3D objects
    2. Print from Photoshop
    3. Print with color management
    4. Contact Sheets and PDF Presentations
    5. Print photos in a picture package layout
    6. Print spot colors
    7. Duotones
    8. Print images to a commercial printing press
    9. Improve color prints from Photoshop
    10. Troubleshoot printing problems | Photoshop
  21. Automation
    1. Creating actions
    2. Create data-driven graphics
    3. Scripting
    4. Process a batch of files
    5. Play and manage actions
    6. Add conditional actions
    7. About actions and the Actions panel
    8. Record tools in actions
    9. Add a conditional mode change to an action
    10. Photoshop UI toolkit for plug-ins and scripts
  22. 3D and technical imaging
    1. Creative Cloud 3D Animation (Preview)
    2. Print 3D objects
    3. 3D painting
    4. 3D panel enhancements | Photoshop
    5. Essential 3D concepts and tools
    6. 3D rendering and saving
    7. Create 3D objects and animations
    8. Image stacks
    9. 3D workflow
    10. Measurement
    11. DICOM files
    12. Photoshop and MATLAB
    13. Count objects in an image
    14. Combine and convert 3D objects
    15. 3D texture editing
    16. Adjust HDR exposure and toning
    17. 3D panel settings
  23. Color Management
    1. Understanding color management
    2. Keeping colors consistent
    3. Color settings
    4. Work with color profiles
    5. Color-managing documents for online viewing
    6. Color-managing documents when printing
    7. Color-managing imported images
    8. Proofing colors
Pastaba:

Photoshop has an updated Image Size dialog box. See Resizing images for more information.

About pixel dimensions and printed image resolution

Pixel dimensions measure the total number of pixels along an image’s width and height. Resolution is the fineness of detail in a bitmap image and is measured in pixels per inch (ppi). The more pixels per inch, the greater the resolution. Generally, an image with a higher resolution produces a better printed image quality.

Photoshop pixel dimensions and printed image resolution
Same image at 72‑ppi and 300‑ppi; inset zoom 200%

Unless an image is resampled (see Resampling), the amount of image data remains constant as you change either the print dimensions or resolution. For example, if you change the resolution of a file, its width and height change accordingly to maintain the same amount of image data.

In Photoshop, you can see the relationship between image size and resolution in the Image Size dialog box (choose Image > Image Size). Deselect Resample Image, because you don’t want to change the amount of image data in your photo. Then change width, height, or resolution. As you change one value, the other two values change accordingly. With the Resample Image option selected, you can change the resolution, width, and height of the image to suit your printing or onscreen needs.

Photoshop Pixel dimensions
Pixel dimensions equal document (output) size times resolution.

A. Original dimensions and resolution B. Decreasing the resolution without changing pixel dimensions (no resampling) C. Decreasing the resolution at same document size decreases pixel dimensions (resampling). 

Quickly display the current image size

If you want to quickly display a document’s current image size, use the information box at the bottom of the document window.

  1. Position the pointer over the file information box, and hold down the mouse button.

File size

The file size of an image is the digital size of the image file, measured in kilobytes (K), megabytes (MB), or gigabytes (GB). File size is proportional to the pixel dimensions of the image. Images with more pixels may produce more detail at a given printed size, but they require more disk space to store and may be slower to edit and print. Image resolution thus becomes a compromise between image quality (capturing all the data you need) and file size.

Another factor that affects file size is file format. Because of the varying compression methods used by GIF, JPEG, PNG, and TIFF file formats, file sizes can vary considerably for the same pixel dimensions. Similarly, color bit-depth and the number of layers and channels in an image affect file size.

Photoshop supports a maximum pixel dimension of 300,000 by 300,000 pixels per image. This restriction places limits on the print size and resolution available to an image.

About monitor resolution

Your monitor’s resolution is described in pixel dimensions. For example, if your monitor resolution and your photo’s pixel dimensions are the same size, the photo will fill the screen when viewed at 100%. How large an image appears on‑screen depends on a combination of factors—the pixel dimensions of the image, the monitor size, and the monitor resolution setting. In Photoshop, you can change the image magnification on‑screen, so you can easily work with images of any pixel dimensions.

Photoshop monitor resolution
A 620‑ by 400‑pixel image displayed on monitors of various sizes and resolutions.

When preparing images for viewing on‑screen, you should consider the lowest monitor resolution that your photo is likely to be viewed on.

About printer resolution

Printer resolution is measured in ink dots per inch, also known as dpi. Generally, the more dots per inch, the finer the printed output you’ll get. Most inkjet printers have a resolution of approximately 720 to 2880 dpi. (Technically, inkjet printers produce a microscopic spray of ink, not actual dots like imagesetters or laser printers.)

Printer resolution is different from, but related to image resolution. To print a high quality photo on an inkjet printer, an image resolution of at least 220 ppi should provide good results.

Screen frequency is the number of printer dots or halftone cells per inch used to print grayscale images or color separations. Also known as screen ruling or line screen, screen frequency is measured in lines per inch (lpi)—or lines of cells per inch in a halftone screen. The higher the resolution of the output device, the finer (higher) a screen ruling you can use.

The relationship between image resolution and screen frequency determines the quality of detail in the printed image. To produce a halftone image of the highest quality, you generally use an image resolution that is from 1.5 to at most 2 times the screen frequency. But with some images and output devices, a lower resolution can produce good results. To determine your printer’s screen frequency, check your printer documentation or consult your service provider.

Pastaba:

Some imagesetters and 600‑dpi laser printers use screening technologies other than halftoning. If you are printing an image on a nonhalftone printer, consult your service provider or your printer documentation for the recommended image resolutions.

Photoshop Screen frequency examples
Screen frequency examples

A. 65 lpi: Coarse screen typically used to print newsletters and grocery coupons B. 85 lpi: Average screen typically used to print newspapers C. 133 lpi: High-quality screen typically used to print four-color magazines D. 177 lpi: Very fine screen typically used for annual reports and images in art books 

Determine a suggested resolution for an image

If you plan to print your image using a halftone screen, the range of suitable image resolutions depends on the screen frequency of your output device. Photoshop can determine a recommended image resolution based on the screen frequency of your output device.

Pastaba:

If your image resolution is more than 2.5 times the screen ruling, an alert message appears when you try to print the image. This means that the image resolution is higher than necessary for the printer. Save a copy of the file, and then reduce the resolution.

  1. Choose Image > Image Size.
  2. Click Auto.
  3. For Screen, enter the screen frequency for the output device. If necessary, choose a different unit of measurement. Note that the screen value is used only to calculate the image resolution, not to set the screen for printing.
  4. For Quality, select an option:

    Draft

    Produces a resolution that is the same as the screen frequency (no lower than 72 pixels per inch).

    Good

    Produces a resolution 1.5 times the screen frequency.

    Best

    Produces a resolution 2 times the screen frequency.

View the print size onscreen

  1. Do one of the following:
    • Choose View > Print Size.

    • Select the Hand tool or Zoom tool, and click Print Size in the options bar.

    The image is redisplayed in its approximate printed size, as specified in the Document Size area of the Image Size dialog box. The size and resolution of your monitor affect the on‑screen print size.

    Pastaba:

    The Print Size command is not available in the Creative Cloud version.

Resampling

Resampling is changing the amount of image data as you change either the pixel dimensions or the resolution of an image. When you downsample (decrease the number of pixels), information is deleted from the image. When you resample up (increase the number of pixels, or upsample), new pixels are added. You specify an interpolation method to determine how pixels are added or deleted.

Photoshop Resampling pixels
Resampling pixels

A. Downsampled B. Original C. Resampled up (selected pixels displayed for each set of images) 

Keep in mind that resampling can result in poorer image quality. For example, when you resample an image to larger pixel dimensions, the image loses some detail and sharpness. Applying the Unsharp Mask filter to a resampled image can help refocus the image details.

You can avoid the need for resampling by scanning or creating the image at a sufficiently high resolution. If you want to preview the effects of changing pixel dimensions on‑screen or to print proofs at different resolutions, resample a duplicate of your file.

Photoshop resamples images using an interpolation method to assign color values to any new pixels based on the color values of existing pixels. You can choose which method to use in the Image Size dialog box.

Nearest Neighbor

A fast but less precise method that replicates the pixels in an image. This method is for use with illustrations containing edges that are not anti-aliased, to preserve hard edges and produce a smaller file. However, this method can produce jagged effects, which become apparent when you distort or scale an image or perform multiple manipulations on a selection.

Bilinear

A method that adds pixels by averaging the color values of surrounding pixels. It produces medium-quality results.

Bicubic

A slower but more precise method based on an examination of the values of surrounding pixels. Using more complex calculations, Bicubic produces smoother tonal gradations than Nearest Neighbor or Bilinear.

Bicubic Smoother

A good method for enlarging images based on Bicubic interpolation but designed to produce smoother results.

Bicubic Sharper

A good method for reducing the size of an image based on Bicubic interpolation with enhanced sharpening. This method maintains the detail in a resampled image. If Bicubic Sharper oversharpens some areas of an image, try using Bicubic.

Pastaba:

You can specify a default interpolation method to use whenever Photoshop resamples image data. Choose Edit > Preferences > General (Windows) or Photoshop > Preferences > General (Mac OS), and then choose a method from the Image Interpolation Methods menu.

Change pixel dimensions of an image

Changing an image’s pixel dimensions affects not only its onscreen size but also its image quality and its printed characteristics—either its printed dimensions or its image resolution.

  1. Choose Image > Image Size.
  2. To maintain the current ratio of pixel width to pixel height, select Constrain Proportions. This option automatically updates the width as you change the height, and vice versa.
  3. Under Pixel Dimensions, enter values for Width and Height. To enter values as percentages of the current dimensions, choose Percent as the unit of measurement. The new file size for the image appears at the top of the Image Size dialog box, with the old file size in parentheses.
  4. Make sure that Resample Image is selected, and choose an interpolation method.
  5. If your image has layers with styles applied to them, select Scale Styles to scale the effects in the resized image. This option is available only if you selected Constrain Proportions.
  6. When you finish setting options, click OK.
    Pastaba:

    For best results when you produce a smaller image, downsample and apply the Unsharp Mask filter. To produce a larger image, rescan the image at a higher resolution.

Change the print dimensions and resolution

When creating an image for print media, it’s useful to specify image size in terms of the printed dimensions and the image resolution. These two measurements, referred to as the document size, determine the total pixel count and therefore the file size of the image; document size also determines the base size at which an image is placed into another application. You can further manipulate the scale of the printed image using the Print command; however, changes you make using the Print command affect only the printed image, not the document size of the image file.

If you turn on resampling for the image, you can change print dimensions and resolution independently (and change the total number of pixels in the image). If you turn off resampling, you can change either the dimensions or the resolution—Photoshop adjusts the other value automatically to preserve the total pixel count. For the highest print quality, it’s generally best to change the dimensions and resolution first, without resampling. Then resample only as necessary.

  1. Choose Image > Image Size.
  2. Change the print dimensions, image resolution, or both:
    • To change only the print dimensions or only the resolution and adjust the total number of pixels in the image proportionately, select Resample Image and then choose an interpolation method.

    • To change the print dimensions and resolution without changing the total number of pixels in the image, deselect Resample Image.

  3. To maintain the current ratio of image width to image height, select Constrain Proportions. This option automatically changes the width as you change the height, and vice versa.
  4. Under Document Size, enter new values for the height and width. If desired, choose a new unit of measurement. Note that for Width, the Columns option uses the width and gutter sizes specified in the Units & Rulers preferences.
  5. For Resolution, enter a new value. If desired, choose a new unit of measurement.
    Pastaba:

    To restore the initial values displayed in the Image Size dialog box, hold down Alt (Windows) or Option (Mac OS), and click Reset.

What affects file size?

File size depends on the pixel dimensions of an image and the number of layers it contains. Images with more pixels may produce more detail when printed, but they require more disk space to store and may be slower to edit and print. You should keep track of your file sizes to make sure the files are not becoming too large for your purposes. If the file is becoming too large, reduce the number of layers in the image or change the image size.

You can view the file size information for an image at the bottom of the application window.

„Adobe“ logotipas

Prisijunkite prie savo paskyros