Resized file size on my Mac is different???

[paulhillion]

I think so or maybe I'm just doing something wrong or not as the case might be. I've got a couple of hundred of pics (each 1 to 5Mb in size) I'm wanting to resize down & save for the web, and so I'm trying to save an action to do the whole lot in one go. I usually resize down to a width of 700 & save as a jpeg on a medium compression setting. Now on my PC I'm sure the file sizes after doing similar were around the 60Kb size but now I'm trying it on my new Powerbook the file sizes come out to around 150kb to 200? I have it in my head that this would be a bit big for website pics, am I wrong?

Any suggestions as to how you guys resize web pics would be most welcome!

Thanks.

Oh yeah I'm using PS CS.

[PacAce]

What command are you using to save the file? "File As" or "Save for Web"? You're right, though. 150KB to 200 seems pretty large to me, too. Are you using Photoshop? What I do to resize my pictures is to use the "Web Photo Gallery" command (File > Automate > Web Photo Gallery). You can pick the image size you want and the image quality and it will even create a thumbnail of each image for you which you can use if you want. There are a bunch of other files created but I just discard anything I don't need.

BTW, to answer your original question about the image sizes in Mac, my Mac image sizes are similar to those of my PC.

[paulhillion]

Yes Photoshop CS. I use the 'file save as' command as I couldn't get the 'save for web' function to work in a action?

I've just tried your suggestion of using the 'web photo gallery' command & that works a treat, all images are an average of 70kb. Funny though how using a compression setting of 6 in 'web photo gallery' produces a different file size from using the 'save as' command using the same compression?

Thanks.

[paulhillion]

Another strange thing! Last week I resized a straight from camera image up to a 20x30 and saved it as a TIF file with no compression which came to around 60Mb, I've just done the same thing to a similar image and it's saved at 163Mb ???

[ppuga]

Hello.

Well first of all, when you use SAVE FOR WEB and SAVE AS, you have different options.

When you use SAVE FOR WEB, an you choose JPG, you have different PRESETS of Compression and quality. And Save for web, automatically change your photo to 72 dpis, and RGB (in case you have it CMYK).
When you want SAVE AS, act as or similar to SAVE FOR WEB, you have to chance other things, manually before you save the picture (this things you can incluide in ACTIONS).

1) IMAGE / IMAGE SIZE, 700 pixels width, 72 dpis.
2) IMAGE / MODE / RGB
3) FILE / SAVE AS / JPG
-JPG OPTIONS you have to put in QUALITY = MEDIUM (4, 5 or 6)
-Then click where it says BASELINE OPTIMIZED (the default setting is in BASELINE "Standard")
You can see in the bottom of that box, the file size

BUT the optimized file you get when you use SAVE FOR WEB I think its better.
You can make an ACTION with SAVE FOR WEB included (in PHOTOSHOP CS), I just made an ACTION that scales the image to 700 pixels width, and then SAVE FOR WEB in JPG MEDIUM.
If you want I can send it to you.

Another thing.
When you save in EPS, TIFF or inclusive JPG, the final size (MB) without or without compression can be diferent depending on the values of the image, if you get a SOLID COLOR image uses less memory than one with a lot of colors, textures, etc. I put here some examples. This can be happening to you when you have this differences in the size of your files. Just a guess, but sounds logic to me.

The black square sizes 846 bytes.
The noise one, sizes 49.6 KB

both of them with the same size, save for web with same conditions, made from same archive.

;)

[paulhillion]

BUT the optimized file you get when you use SAVE FOR WEB I think its better.
You can make an ACTION with SAVE FOR WEB included (in PHOTOSHOP CS), I just made an ACTION that scales the image to 700 pixels width, and then SAVE FOR WEB in JPG MEDIUM.
If you want I can send it to you.

If you could that'd great, I'll send you a PM with my email address, thanks!

I've solved the mystry with my different .Tif file sizes, when I came to resize the 2 files up to 20x30 I had done so with a different ppi resolution, the difference between enlarging at 180 ppi or 300 ppi results in about a 100mb difference.

Learning all the time!

[ppuga]

Paul, I just send you the email with the action, hopes it helps!

And yes, and between 180 to 300 ppis, theres a lot of difference, here at work all the images I use have to be at 300ppis, at the size they will be used for print, to capture the best print quality, for magazine ads, if I have to make a newspaper ad, I use 170 to 240 ppis instead because of the low quality a newspaper has.

I think every one here learns a lot! jeje I'm learning a lot too!

Take care. ;)

[Qurlyjoe]

Mac applications, including Photoshop, typically will include by default a "preview" image of any file you save, which is used by the Finder to display on the desktop. This will increase the final file size by varying amounts, depending on the quality setting you use. This is regardless of the file type.

[ppuga]

Thats when you save a JPG or other kind of files with SAVE AS, you get this preview, so you can see the PREVIEW in the ICON at the desktop.
But when you use SAVE FOR WEB, many times you can't see this Preview ICON in the desktop, just see that its a PS file ICON (in MAC OS 9.2 and olders). In MAC OS X you see the preview always.