File resizing

[retro]

I am still new to the game and don't know how to "downsize" my photos. I am using Photoshop CS. Is there a tutorial on here or any quick info would be appreciated. Thanks in advance

-retro

[robertwgross]

Resample is a good word to use.

For example, if I have an 18MB TIF file that I want to publish to my web site, then I resample the file downward (with the verticle-horizontal aspect held constant). I resample it downward to 50%-50%, 40%-40%, and keep going until the TIF filesize will be roughly 1.2 to 1.5MB. Then I do a conversion/export to the JPEG format. When saving as a JPEG, normally I have to specify a quality.

When all of the smoke clears, I will have a JPEG file of roughly 50-100KB, which is about the size and filesize are correct for the web.

---Bob Gross---

[Scottes]

This is probably more appropriate in the Post Processing forum. More Photoshop users frequent there.

Here's one tutorial on Cropping which contains some resizing information. You can Crop and Resize in a single step, which is pretty darn convenient. http://photography-on-the.net/forum/showthread.php?t=34567

For a quick answer, what I do is first set my status bar to show the pixel dimensions:

http://www.itsanadventure.com/postimages/docdimensions.gif

Then I click on Image... Image Size, and set the Width and Height to 90 percent and ensure that the bottom "Resample Image" is set to Bicubic.

http://www.itsanadventure.com/postimages/imagesize.gif

And I hit OK. I keep doing this until the image is a little larger than I want. To get right to the final size I want, I use Image Size again, but leave the top boxes set to pixels this time, and enter the pixel size I want, like 640x480 or whatever.

The above is a pain in the butt. The repeated 90% resize is actually done in an Action so I just have to click a button a few times. Or, you could just do the Image Size once, and go from the full image right down to the final image in one step. I'd recommend using Bicubic Sharper if you do that.


And to explain: Many believe that resizing an image in several steps, each changing the image 10% at a time, results in a better image. I definitely believe that it does, and have run many tests to prove it to me. However, the difference is slight, and might not be worth your time and effort. If so, do Image Size in one step.

[robertwgross]

And to explain: Many believe that resizing an image in several steps, each changing the image 10% at a time, results in a better image.

I mentioned that to a friend one time, and she thought that I meant to resample the image to 10% several times. Obviously, that gets poor results. Reducing the size by 10% gets you to 90%.

---Bob Gross---

[nosquare2003]

I like the resizing function of the free software:

http://www.irfanview.com/

[Molydood]

go to microsoft.com and get the resizing powertool, its very small, and free, and I use it all the time within explorer

[central183]

Don't forget PHotoshop's "Save for Web" (File/Save for Web). After you have cropped the image using the above techniques, you can use the save for web function to make an acceptable size for web posts. You should plan on keeping JPEG files 30K or less for dial-up audience and 100k or less for broadband audience. The save for web dialog easily lets you compress to fit a certain size. It also does not save a thumbnail in the file, thus reducing size. This is why it's an advantage over just saving a copy of a JPEG from the file menu.

[PhotosGuy]

"Save for Web" (File/Save for Web). After you have cropped the image using the above techniques, you can use the save for web function to make an acceptable size for web posts. You should plan on keeping JPEG files 30K or less for dial-up audience and 100k or less for broadband audience.

I'm not concerned with ultimate quality for the web & usually resize in one step Image > Image Size. Enter the 72ppi first, then the dimensions.
If you have any concerns about people using your images from your site & using them without your permission, then I'd recommend keeping the size on the small side - 400X600 @ 72 ppi & 30-50KB.

[retro]

I still don't understand the process of resizing the picture. I took a picture of my friend in a marathon today and have some processing questions. Problem is the picture in high quality shot at 18Megs and I don't know what size is reasonable to post on here. Image venue is asking for a maximum of 1024kb to upload. Help!

[PhotosGuy]

I don't know what size is reasonable to post on here.

See what I said just above.
Then go here:
http://www.ephotozine.com/techniques/viewtechnique.cfm?recid=8

[retro]

Thanks for the help. This is the picture I am posting for help. Just wanted to show the fruits of your labors...

http://www.imagevenue.com/host/web1/6e7f6_Jakesracesmallforweb.jpg [/img]