Easy-to-follow video tutorials help you learn software, creative, and business skills.Become a member

Resize vs. Resample

From: Photoshop CS5 Essential Training

Video: Resize vs. Resample

Okay. So you've got an image off your Digital Camera. You've got a real nice, fancy DSLR and shoots 18 megapixels, and you bring it into Photoshop and you're like, I just need to create a 4x6 print of this and print it out on inkjet printer. How do I do that? How do I change the size of my image? Typically what you do is you go to the Image Size dialog box that's located under the Image menu, so Image, Image Size. And let's talk about this dialog box because it's potentially confusing for a lot of people actually, even talking to people who've been using Photoshop for years and they still are kind of confused by what this dialog box is all about.

Resize vs. Resample

Okay. So you've got an image off your Digital Camera. You've got a real nice, fancy DSLR and shoots 18 megapixels, and you bring it into Photoshop and you're like, I just need to create a 4x6 print of this and print it out on inkjet printer. How do I do that? How do I change the size of my image? Typically what you do is you go to the Image Size dialog box that's located under the Image menu, so Image, Image Size. And let's talk about this dialog box because it's potentially confusing for a lot of people actually, even talking to people who've been using Photoshop for years and they still are kind of confused by what this dialog box is all about.

So let's make it simple. I'd break it into two parts. There's the Upstairs and the Downstairs, Upstairs easy, Downstairs hard. Now, why is the Downstairs harder than Upstairs? Because Downstairs has one more thing that you have to think about and that's Resolution. We'll talk about that in just a second. The other potentially confusing thing about this dialog box, that actually has two modes. It can be used to resize an image or it can be used to resample an image, and there's a difference between resize and resample.

The default is to have this turned on to Resample. I'm going to turn that off. Note that when I do that, the Upstairs becomes unavailable. I can't actually change the number of pixels in the file when Resample is turned off. Which means all I'm really doing is changing how this image will be printed, what size it will be printed at when you hit the Print command? You're not actually changing the amount of information of the file at all, only how it gets output. So I said I wanted a 4x6.

So right now the width of the camera. This is a very large dimensionally file. It's 32 roughly inches by 48 inches, but has a very low resolution at 72 pixels per inch here. If I change the Width to 4, so 4 inches, Because I'm not changing the number of pixels in the file, I'm just changing the Dimensions, in this case I'm making the dimensions go down, resolution has to go up, because it's the same number of pixels. Because just to fit into a smaller rectangle the pixels have to get smaller.

So the smaller the pixel, the higher the resolution. That's kind of how this works. Now, okay, you might understand that, great! I've turned off Resample, which means it's a non-destructive action. I'm not changing the number of pixels in the file. I'm only changing how it's going to print. You click OK, and this is where people sometimes get confused, because it didn't appear that anything happened. The file doesn't look different on screen and that's exactly what's supposed to happen because you did a Resize, not a Resample. If I had gone to 100%, let's go ahead and double-click on the Zoom tool, and I'm viewing the Image at 100% view, the Actual Pixels view.

Here you're seeing every single pixel in the image represented by 1 pixel on the screen of the display. You can see there's a lot of pixels here. It's a big file. If I go back to Image, Image Size, and you can see it's a 4x6 at 584 pixels per inch. Let's take this back to a 20 inch file, so a 20x30. The Resolution went down in this case, because I made the dimensions larger, again because Resample is turned off, the number of pixels in the file is not changing, so the pixels have to get larger to fill the larger dimensions that we're changing here.

I go ahead and click OK. Again, you're might be scratching your head on, but nothing happened on screen. So the summary there is when the Resample is turned off, you're not actually changing anything about the file within Photoshop except how the file will be printed when you use the Print command. Let's go back to Image Size again, and let's take this Resolution back to where we started, 72 which forces the dimensions to go up. Let's turn Resample on this time. Now when Resample is turned on, suddenly the Upstairs is available to use again because this is potentially a lossy operation.

You're actually going to be changing the number of pixels in the file. Well either be removing pixels, in which case the geeky term for that is down-sampling, or you'll be adding pixels that don't even exist, and that's called up-sampling. If I change the Width here to 4, the Height retains its proportion by default. So it goes to 6 inches. But note that the resolution did not change anymore, because they're not connected anymore when the Resample is turned on. You can change these independently or as when Resample was turned off, changing the width or heights change the resolution correspondingly and vice-versa, by changing the resolution, the width and height changes.

Now if you take a look at the Upstairs, it's actually giving you a clue of what's going on here. The original file was 23 MB, but because we made the dimension smaller and we did not change the resolution, we are throwing away a gigantic amount of those pixels and ending up with a 364 K File. Now if I click OK, you're like oh! Something happened. It got smaller on screen. Yes, it got smaller on screen because we actually threw away a large number of pixels. We're still viewing it at the 100% view, and because there is fewer pixels in the file it takes up less screen real estate to represent the image.

I am going to undo that, Command+Z, Ctrl+Z on Windows, and go back to Image, Image Size. Now when you have Resample turned on, which again is the default, you're not just changing how this file will be printed when you hit the Print command, you're also changing the physical size of the file, the number of pixels in that document. And like I said if you change the dimension smaller and keep the resolution low, you're getting rid of pixels that were present, so that you don't feel you need anymore. If you make the dimensions larger and/or the resolution larger than what you started with, that's called upsampling.

You're asking Photoshop to invent pixels that don't exist. So usually a question I get is okay, I've got this file. It's as big as it can be as it is, but I need to make it a little bit bigger. Maybe I'm starting with an 8x10 image, 300 dpi, and I want to print it as an 11x14 let's say. So how big can you make it in Photoshop? Well typically, what most people say is if you're going up about say 25% from your original dimensions, you're probably not going to be able to spot that too badly. You probably get a good enough job there, especially it's because the larger the print, the farther away you're intended to be from, when you're looking at it.

If you are looking at a billboard let's say, you're not standing right next to a billboard, you're looking at a billboard from hundreds of feet away potentially. So you don't need a lot of resolution in that regard because you're going to be looking at it from quite a distance. So anyway, what all I'm trying to say is if you're going to up-sample an image in Photoshop, going anywhere from 10-20 % larger than what you're starting with, it's probably not the end of the world and you probably won't even notice. If you need to go much larger than that, then there actually are third-party products that do a much better job of upsampling beyond the capabilities of what Photoshop may do on its own.

If that's something you need, I check out one of the products from onOne Software. That's just onone.com or ononesoftware.com and they have a product called Genuine Fractals that you can take a look at that does a really good job of up-sampling beyond that 20% threshold that I'm recommending you stay within. Last point to make is that, if you are resampling an image whether you're making it have fewer pixels or have more pixels, you actually have a choice of how the resampling gets done. There's another geeky term called an Algorithm. What math should Photoshop use to get you the result you're looking for? The default is Bicubic, again another geeky name.

And at least now, they actually give you a description of what that means. It's best for smooth gradients. There are two other options that you might want to take a look at, one is Bicubic Smoother, so if you're making that image larger than the number of pixels you have, you would want to change the algorithm for resampling to Bicubic Smoother. It's going to give you much better results. Bicubic Sharper is typically what you want to do if you're taking a file smaller, which most of time and especially with today's digital cameras that are capturing so many pixels, you typically are down-sampling your images, especially if you post it into a webpage or doing a photo gallery or just showing up on a mobile device or something, you're certainly not going to send these huge amount of pixels to those particular outputs.

So I actually change my default Resampling Algorithm to Bicubic Sharper and I'll show you how to do that in just a moment. But typically we're going to get a lot better results by choosing Bicubic Sharper. What that does is make the file smaller, and does a sharpening pass behind the scenes to retain edge detail. Okay, so if I was doing this as a 4x6 to my inkjet printer, in the previous video we talked about what type of resolution you need based on output, it turns out that inkjet printing, a good number is somewhere between 240 and 300 dots per inch. We said we wanted this to be a 4x6, and so I'm down-sampling this image down to about 4 MB, the Dimensions are 4x6, the Resolution is 240, I've chosen Bicubic Sharper to give me the best results, go ahead and click OK, and there is my file and I'm ready to go ahead and print it.

If you were following the Algorithm discussion there about Bicubic versus Bicubic Smoother and Bicubic Sharper, then you'll find that most of the time you're going to be starting for a large file and making it smaller, then you'll want to change your Preference. Go to Photoshop, Preferences on the Mac, and we can just go to General on PC, we're going to the Edit menu, or Command or Ctrl+K will just pop-open the dialog. Right there in the General category, the Image Interpolation default, it's right now set to Bicubic. That's the out-of-the-box default. If you're finding you're constantly making your images smaller, then change it to Bicubic Sharper as the default, so that the next time you go to Image Size, that dialog, it will already be set to the interpolation choice that's going to give you the better looking result.

Show transcript

This video is part of

Image for Photoshop CS5 Essential Training
Photoshop CS5 Essential Training

154 video lessons · 94317 viewers

Michael Ninness
Author

 
Expand all | Collapse all
  1. 6m 10s
    1. Welcome
      1m 47s
    2. What is Photoshop?
      2m 49s
    3. Using the exercise files
      1m 34s
  2. 28m 29s
    1. What is Adobe Bridge?
      1m 54s
    2. Getting photos from a camera
      3m 39s
    3. A tour of the different workspaces in Adobe Bridge
      4m 58s
    4. Customizing how thumbnails are displayed
      3m 35s
    5. Changing obscure camera file names with the Batch Rename command
      2m 36s
    6. Adding basic metadata to every image with metadata templates
      3m 36s
    7. Creating and applying keywords to images
      4m 6s
    8. Viewing images in Full Screen Preview mode
      4m 5s
  3. 23m 4s
    1. Using Review mode to filter out rejects
      5m 27s
    2. Protecting the keepers by saving them in collections
      3m 18s
    3. Rating images
      3m 15s
    4. Using the Filter panel to view different subsets
      4m 43s
    5. Viewing final choices in a slideshow
      2m 12s
    6. Organizing groups of images into stacks
      4m 9s
  4. 30m 50s
    1. Raw vs. JPEG files
      5m 13s
    2. Why you should start in Camera Raw instead of Photoshop
      5m 9s
    3. A tour of the Camera Raw user interface
      6m 44s
    4. Previewing before and after adjustments
      4m 2s
    5. Toggling onscreen Shadow/Highlight clipping warnings
      2m 37s
    6. Choosing output settings
      2m 45s
    7. Saving a copy without going to Photoshop
      4m 20s
  5. 41m 34s
    1. Eliminating red-eye with the Red Eye Removal tool
      1m 13s
    2. Improving composition with the non-destructive Crop tool
      3m 33s
    3. Correcting a rotated horizon line with the Straighten tool
      3m 5s
    4. Fixing color casts with the White Balance tool
      2m 13s
    5. Fixing blown-out highlights with Recovery
      2m 36s
    6. Revealing hidden shadow detail with Fill Light
      1m 47s
    7. Reducing distracting color noise with Noise Reduction
      5m 37s
    8. Removing color fringes with Chromatic Aberration
      2m 36s
    9. Sharpening the details
      8m 59s
    10. End to end: Taking a so-so photo and making it great
      9m 55s
  6. 39m 5s
    1. Fixing blown-out skies with the Graduated Filter tool
      4m 34s
    2. Retouching blemishes with the Spot Removal tool
      5m 41s
    3. Making local adjustments with the Adjustments Brush
      4m 28s
    4. Quick portrait retouching technique using Clarity
      4m 33s
    5. Converting to black and white
      3m 36s
    6. Editing images directly with the Targeted Adjustments tool
      4m 18s
    7. Easy sepia and split tone effects
      2m 35s
    8. Adding digital film grain texture effects
      2m 46s
    9. Adding vignettes and border effects
      2m 13s
    10. Saving variations within a single file with Snapshots
      4m 21s
  7. 15m 48s
    1. Copying settings from one file and pasting across another in Adobe Bridge
      3m 7s
    2. Processing multiple files in Camera Raw
      2m 28s
    3. Saving and using a library of Camera Raw presets
      5m 33s
    4. Using Image Processor to batch process multiple files
      4m 40s
  8. 30m 39s
    1. Opening files from Adobe Bridge
      3m 1s
    2. Opening files from Mini Bridge
      3m 28s
    3. Customizing the Mini Bridge panel
      2m 57s
    4. Changing Mini Bridge so it auto-collapses
      1m 20s
    5. The Application frame
      2m 16s
    6. The Application bar
      1m 16s
    7. Switching and saving workspaces
      4m 23s
    8. Panel management
      5m 31s
    9. Switching tools using the keyboard
      3m 18s
    10. Customizing the keyboard shortcuts
      3m 9s
  9. 16m 12s
    1. Tabbed documents
      2m 1s
    2. The Arrange Documents widget
      1m 38s
    3. How to stop Photoshop from tabbing documents
      3m 34s
    4. Pan and zoom
      5m 21s
    5. Cycling through the different screen modes
      3m 38s
  10. 36m 59s
    1. File formats
      13m 6s
    2. What resolution does your image need to be?
      10m 15s
    3. Resize vs. Resample
      9m 40s
    4. How big a print can you make with your image?
      3m 58s
  11. 42m 17s
    1. Crop options
      4m 12s
    2. Hide vs. Delete for the Crop tool
      3m 30s
    3. Bringing back hidden pixels with Reveal All
      1m 34s
    4. Making the canvas bigger with the Crop tool
      6m 1s
    5. Making the canvas bigger by a specific amount with Relative Canvas Size
      1m 39s
    6. Correcting perspective with the Crop tool
      3m 5s
    7. Straightening a crooked image
      50s
    8. Scaling, skewing, and rotating with Free Transform
      4m 12s
    9. Nondestructive transformations with Smart Objects
      4m 2s
    10. Warping images
      3m 40s
    11. Preserving the important elements with Content-Aware Scaling
      9m 32s
  12. 54m 42s
    1. The Background layer
      5m 14s
    2. Using a layer mask instead of deleting pixels
      4m 12s
    3. Loading multiple images into a single Photoshop document as layers
      1m 30s
    4. Naming, hiding, creating, and deleting layers
      4m 18s
    5. Changing the stacking order of layers
      2m 51s
    6. Selecting layers without using the Layers panel
      6m 28s
    7. Transforming layers
      7m 16s
    8. Aligning and distributing layers
      3m 51s
    9. Changing the opacity of layers
      2m 57s
    10. Organizing layers into groups
      2m 55s
    11. Saving variations with layer comps
      5m 3s
    12. When to merge and rasterize layers
      5m 0s
    13. Flatten vs. Save As (a Copy)
      3m 7s
  13. 1h 4m
    1. Using the Marquee and Lasso tools
      7m 23s
    2. Transform selections
      2m 40s
    3. Quick Mask is your friend
      4m 31s
    4. Converting a selection into a layer mask
      6m 33s
    5. Using the Quick Selection tool
      3m 1s
    6. Re-selecting a previous selection
      1m 35s
    7. Improving a selection with Refine Edge
      4m 21s
    8. Touching up a layer mask with the Brush tool
      12m 7s
    9. Changing the opacity, size, and hardness of the painting tools
      2m 59s
    10. Blending images with a gradient layer mask
      4m 53s
    11. Swapping heads in a family portrait
      3m 53s
    12. Combining multiple exposures with the Blend If sliders
      6m 26s
    13. Replacing the sky in an image
      4m 19s
  14. 1h 1m
    1. Introducing adjustment layers
      7m 57s
    2. Starting with a preset
      4m 25s
    3. Improving tonal quality with Levels
      10m 28s
    4. Increasing midtone contrast with Curves
      5m 4s
    5. Removing a color cast with Auto Color
      5m 56s
    6. Changing the color temperature with Photo Filter
      2m 55s
    7. Shifting colors with Hue/Saturation
      9m 0s
    8. Making washed out colors pop with Vibrance
      2m 46s
    9. Converting color to black and white
      5m 49s
    10. Controlling which layers are affected by an Adjustment Layer
      7m 28s
  15. 11m 32s
    1. Shadow/Highlight
      9m 3s
    2. Matching color across multiple images
      2m 29s
  16. 34m 12s
    1. Removing blemishes with the Spot Healing brush
      6m 21s
    2. Quick technique for smoothing skin and pores
      8m 23s
    3. Taming flyaway hair
      4m 47s
    4. Making teeth bright and white
      1m 43s
    5. De-emphasizing wrinkles
      4m 41s
    6. Removing unwanted details with Content Aware Fill
      4m 26s
    7. Body sculpting with Liquify
      3m 51s
  17. 21m 6s
    1. Creating panoramas with Photomerge and Auto-Blend
      7m 20s
    2. Combining multiple frames of an action sequence
      8m 30s
    3. Combining group shots with Auto-Align
      5m 16s
  18. 25m 36s
    1. Overview of filters
      4m 6s
    2. Applying filters nondestructively with Smart Filters
      4m 45s
    3. Giving an image a soft glow with the Gaussian Blur filter
      4m 41s
    4. Adding noise to an image with the Add Noise filter
      3m 34s
    5. Sharpening an image with Unsharp Mask
      4m 12s
    6. Giving an image more texture with the Texturizer
      1m 17s
    7. Applying a filter to multiple layers
      3m 1s
  19. 30m 44s
    1. Cycling through the blending modes
      4m 43s
    2. Three blending modes you must know
      6m 41s
    3. Adding a lens flare effect with Screen
      3m 33s
    4. Making a cast shadow more realistic with Multiply
      4m 33s
    5. Creating a diffused contrast glow effect with Overlay
      6m 2s
    6. Sharpening an image with High Pass and Overlay
      5m 12s
  20. 21m 39s
    1. Character (point) type
      8m 19s
    2. Paragraph (area) type
      4m 42s
    3. Type on a path
      2m 54s
    4. Clipping an image inside type
      2m 24s
    5. Warping type
      3m 20s
  21. 20m 35s
    1. Adding a drop shadow effect
      4m 43s
    2. Adding an outer glow effect
      3m 13s
    3. Adding a border around an image
      2m 53s
    4. Copying layer effects and applying them to other layers
      2m 3s
    5. Saving layer styles and applying them in other documents
      2m 42s
    6. How (and when) to scale layer effects
      5m 1s
  22. 16m 6s
    1. Creating PDF contact sheets
      6m 41s
    2. Exporting web photo galleries
      6m 8s
    3. Saving for the web
      3m 17s
  23. 1m 19s
    1. Goodbye
      1m 19s

Start learning today

Get unlimited access to all courses for just $25/month.

Become a member
Sometimes @lynda teaches me how to use a program and sometimes Lynda.com changes my life forever. @JosefShutter
@lynda lynda.com is an absolute life saver when it comes to learning todays software. Definitely recommend it! #higherlearning @Michael_Caraway
@lynda The best thing online! Your database of courses is great! To the mark and very helpful. Thanks! @ru22more
Got to create something yesterday I never thought I could do. #thanks @lynda @Ngventurella
I really do love @lynda as a learning platform. Never stop learning and developing, it’s probably our greatest gift as a species! @soundslikedavid
@lynda just subscribed to lynda.com all I can say its brilliant join now trust me @ButchSamurai
@lynda is an awesome resource. The membership is priceless if you take advantage of it. @diabetic_techie
One of the best decision I made this year. Buy a 1yr subscription to @lynda @cybercaptive
guys lynda.com (@lynda) is the best. So far I’ve learned Java, principles of OO programming, and now learning about MS project @lucasmitchell
Signed back up to @lynda dot com. I’ve missed it!! Proper geeking out right now! #timetolearn #geek @JayGodbold
Share a link to this course

What are exercise files?

Exercise files are the same files the author uses in the course. Save time by downloading the author's files instead of setting up your own files, and learn by following along with the instructor.

Can I take this course without the exercise files?

Yes! If you decide you would like the exercise files later, you can upgrade to a premium account any time.

Become a member Download sample files See plans and pricing

Please wait... please wait ...
Upgrade to get access to exercise files.

Exercise files video

How to use exercise files.

Learn by watching, listening, and doing, Exercise files are the same files the author uses in the course, so you can download them and follow along Premium memberships include access to all exercise files in the library.


Exercise files

Exercise files video

How to use exercise files.

For additional information on downloading and using exercise files, watch our instructional video or read the instructions in the FAQ .

This course includes free exercise files, so you can practice while you watch the course. To access all the exercise files in our library, become a Premium Member.

Join now Already a member? Log in

Are you sure you want to mark all the videos in this course as unwatched?

This will not affect your course history, your reports, or your certificates of completion for this course.


Mark all as unwatched Cancel

Congratulations

You have completed Photoshop CS5 Essential Training.

Return to your organization's learning portal to continue training, or close this page.


OK
Become a member to add this course to a playlist

Join today and get unlimited access to the entire library of video courses—and create as many playlists as you like.

Get started

Already a member ?

Become a member to like this course.

Join today and get unlimited access to the entire library of video courses.

Get started

Already a member?

Exercise files

Learn by watching, listening, and doing! Exercise files are the same files the author uses in the course, so you can download them and follow along. Exercise files are available with all Premium memberships. Learn more

Get started

Already a Premium member?

Exercise files video

How to use exercise files.

Ask a question

Thanks for contacting us.
You’ll hear from our Customer Service team within 24 hours.

Please enter the text shown below:

The classic layout automatically defaults to the latest Flash Player.

To choose a different player, hold the cursor over your name at the top right of any lynda.com page and choose Site preferences from the dropdown menu.

Continue to classic layout Stay on new layout
Exercise files

Access exercise files from a button right under the course name.

Mark videos as unwatched

Remove icons showing you already watched videos if you want to start over.

Control your viewing experience

Make the video wide, narrow, full-screen, or pop the player out of the page into its own window.

Interactive transcripts

Click on text in the transcript to jump to that spot in the video. As the video plays, the relevant spot in the transcript will be highlighted.

Are you sure you want to delete this note?

No

Your file was successfully uploaded.

Thanks for signing up.

We’ll send you a confirmation email shortly.


Sign up and receive emails about lynda.com and our online training library:

Here’s our privacy policy with more details about how we handle your information.

Keep up with news, tips, and latest courses with emails from lynda.com.

Sign up and receive emails about lynda.com and our online training library:

Here’s our privacy policy with more details about how we handle your information.

   
submit Lightbox submit clicked
Terms and conditions of use

We've updated our terms and conditions (now called terms of service).Go
Review and accept our updated terms of service.