Image sizing problems...

srtiwari

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Each time I want to upload an image, whether here, on Flickr, or elsewhere on the Web, I have to resize it to given parameters. On RFF the limit is 200Kb.
Starting from a scanned image (often over 50 MB in size), I Post-process, and then save a copy as Jpeg, smaller in size and resolution (75 mp/inch), and use the "Quality" option make it JUST under 200Kb.
But, I end up doing it over and over as the size changes- it may be 355Kb when image resizing in PS, 150Kb as you are saving it, and 250 Kb once the file is saved.
Whereas I understand that the file size cannot be accurately predicted by just the resolution and image size, I'm not sure why it continues to change even after the post-processing is finished. Apart from the sheer aggravation of it, I'd rather not "save" the Jpeg any more times than I need to.

I don't know what others do, but I haven't figured out an easy way yet. Can anybody tell me of a simple way to get around this problem ? I'd like to maximize image size and quality, but keep the file under a certain size.
 
Me too. Somebody must have the answer. I see images put up here that open within the post at a useful size whereas others (and mine) seem to end up as tiny little thumbnails that you have to click on to open and then they appear in a separate window and still not the size that others achieve within their text message.
 
The way to get images inline is to post them somewhere on the web, and link to them.

The way to deal with multiple file sizes is to make ONE master file (typically tiff) and to export jpgs as required. You throw these away, and start with the original again. (lightroom, for example, makes this seamless). Do not worry about making it the maximum "quality" (I use 50% and 1024 long edge size, for example). If you are not printing from it, it hardly matters.
 
Don't mess around with jpegs, they change file size constantly ... tiifs are the way to go and only using jpegs for web posting.

ACDSee Pro has an excellent resizing function in it editing software that gives a pedicted file size output for jpegs.
 
Linking does not solve the problem if someone really wants to upload here in RFF e.g. in the gallery. It's a little bit try and error. The 200kb in RFF is not really much, other forums are not so restrictive. When exporting to jpg you could use the save to web option in PS. This throws away the EXIF Information and saves a few KB too. For upload in the RFF gallery I resize to max. 800px (long side) then I get a reasonable quality under 200kb.
 
Don't mess around with jpegs, they change file size constantly ... tiifs are the way to go and only using jpegs for web posting.

ACDSee Pro has an excellent resizing function in it editing software that gives a pedicted file size output for jpegs.

He's using JPEGs for the web posting only, saved after resizing his original fullres images. Problem is he is having trouble getting exact file size needed for RFFs gallery, which has size limits.

I don't know how to get around it either. All the years I've used PS, I've never had a need to have a certain file size since I post pics on my own website, nowhere else.
 
I would love to know a nice, small tool as well, which can downsize a JPG to a given size, rather than experimenting with quality and compression settings, to try, to fit a given size.

Keith - your new avatar is crazy cool !!!
 
In PS i change resolution to 72 pixels per inch and the pixel dimensions to 800 max width or height depends on orientation, check all 3 boxes; Scale styles, Constrain proportions and resample image. Lastly in the drop down I choose bicubic sharper (best for reduction). I then have it hosted by either tinypic.com or smugmug.com. Size come out perfect all the time. I also use this in uploading to the gallery but files are direct from computer. Btw, I save in low or medium jpg.
 
I think the additional kB you get when saving the picture to JPEG in PS is all the additional information that is stored with the image (EXIF, etc) and also the thumbnails (for Windows, for MAC) - which you do not need for Flickr or RFF.
Just for testing Try to make a tiny little image in the PS of some 40x40 pixels and compress it strongly. PS will show you tiny size that the image should have, however in the result there will be at leas 40kB more. Check you settings in PS or other application that you use for resizing the images.

Have a look at XnView for size-tight resizing.
 
He's using JPEGs for the web posting only, saved after resizing his original fullres images. Problem is he is having trouble getting exact file size needed for RFFs gallery, which has size limits.

I don't know how to get around it either. All the years I've used PS, I've never had a need to have a certain file size since I post pics on my own website, nowhere else.


Chris,

With ACDSee Pro in the edit function you enter your required pixel dimensions which is generally 800 on the long side for web posting and it will give an estimated file size at the default resolution setting which is around 85% from memory. This setting can be decreased or increased before saving depending whether you want the output file larger or smaller than the estimate.

I'm sure photoshop has the same capability and from memory it's even more straight forward than ACDSee.

I sometimes wonder how many people aren't posting images in our gallery because they can't achieve that file size requirement of 200 max!
 
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In my thread on the 9x12 VAG, I simply posted the file to flickr and linked to it through the image icon. I wasn't sure myself if it would work since I didn't resize, and would have had to reinstall PS sooner than I wanted (recent virus has caused me to have to re-do a lot of things). But it worked without resizing. I guess as it is not uploaded but only linked?
 
I use a Mac, so ACDC not usable I think.


Even if you post on an external website, in order to have inline images, the file size limitation would apply. This is what I do anyway, since , unlike GMail, RFF has no direct upload tool to the forums.
The best is to post inline images that are large enough to fill the page width, without requiring the use of scroll bars.The trick is to do that at best possible quality without exceeding the 200Kb limit. I have managed to do it a couple of times, but can't remember how.
Maybe someone can write and post a PS Actioin for this. I'm sure many will use it.
 
maybe make yourself a little table that shows for each size image that you typically process what the output size will be. the variables are length, width, ppi (72 for the web so this is constant), and compression/quality (the "save for web" option). E.g. 8x10: (8*72)*(10*72)*60% = 248Kb This answer tells you that the you'll have to "shrink" the display size proportionately from 8x10 to, say, 6x7.5. Which would give you (6*72)*(7.5*72)*60% = 140Kb.

Doing the table once would save you the iterations you do now for each image.
 
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