CS5. <sAVE as> unusual things.??

[nebulaoperator]

sAVE as unusual things.??
Hi everyone,

I currently working on the 16 bit file. before going for <save as> I change it to 8bit . All I need is up to 800kb file. So after 8bit conversion I go to <image size> I make it 72dpi. then straight to <save as> and file still 1.3MB even if I lower quality to low it only goes down to 1.1MB What is going on here?
Thank you.Neb

[John Wheeler]

Hi Nebulaoperator
Not sure if you were saving in JPG or otherwise. Image size is mostly determined by

- Total number of pixles (width x height)
- 8 vs 16 bit
- number of color channels (RGB vs CMYK)
- file format
- compression used with that file format
- Layer information if using PSD, TIFF, or similar
- Flattened copy is saved with Maximize Compatibiity
- minor amount from including ICC profile and metadata

Changing DPI does not change the file size by itself

I suggest giving "File > Save for Web and Devices" You can tune in the file size you want with that output option. Hope that helps.

[mistermonday]

Originally Posted by nebulaoperator

sAVE as unusual things.??
Hi everyone,

I currently working on the 16 bit file. before going for <save as> I change it to 8bit . All I need is up to 800kb file. So after 8bit conversion I go to <image size> I make it 72dpi. then straight to <save as> and file still 1.3MB even if I lower quality to low it only goes down to 1.1MB What is going on here?
Thank you.Neb

If you have changed the Image Size without turning on the Resample box, then you still have the same number of pixels in the file, you have just made the display resoultion 1/4 as large but have increased the image dimensions by 4x, resulting in no change.
If you did resample , you image will be considerably smaller. However, if you have started with a large image, 12-24 megapixel, you may easily have a jpg that exceeds 1MB at medium quality.
Regards, Murray

[nebulaoperator]

Hi John,
Well: RGB, 8bit, Jpeg, flattened or other non flattened any way I do happens same. just tried other file and things go smooth.I am not really a fan of <web save>. No idea. have to look careful look at it.

[nebulaoperator]

Hi Murray,
This is how it looks:

[mistermonday]

Originally Posted by nebulaoperator

Hi Murray,
This is how it looks:

The max size of your image with absolutely no compression (tiff or PSD) will be 571 x 800 x 3 = 1.370MB
You need to remember that an RGB image needs 1 byte per channel to store a pixel. Now if you do a File>Save As jpg you should see in the dialog box the estimated file size that will result as you lower the quality from 12 to 11 to 10...all the way to 1. PS makes an approximation but it is usually very accurate. At a quality level of 10 there is usually a 4:1 reduction.
Regards, Murray

[nebulaoperator]

Originally Posted by mistermonday

The max size of your image with absolutely no compression (tiff or PSD) will be 571 x 800 x 3 = 1.370MB
You need to remember that an RGB image needs 1 byte per channel to store a pixel. Now if you do a File>Save As jpg you should see in the dialog box the estimated file size that will result as you lower the quality from 12 to 11 to 10...all the way to 1. PS makes an approximation but it is usually very accurate. At a quality level of 10 there is usually a 4:1 reduction.
Regards, Murray

The thing is that slider you are talking about is not reducing. Going from 12 to 1 it only reduces from 1.3MB to 1.1MB. Isn't it strange?

[mistermonday]

Originally Posted by nebulaoperator

The thing is that slider you are talking about is not reducing. Going from 12 to 1 it only reduces from 1.3MB to 1.1MB. Isn't it strange?

Test: Try setting the quality very low (like 1 or 2) and actually click the OK button and then use windows explorer to check the actual size of the resulting saved file. If the actual file size is a lot smaller, then you will know that there is something wrong with PS's jpg size previewer. What version of PS are you using and under what OS?
Regards, Murray

[nebulaoperator]

Originally Posted by mistermonday

Test: Try setting the quality very low (like 1 or 2) and actually click the OK button and then use windows explorer to check the actual size of the resulting saved file. If the actual file size is a lot smaller, then you will know that there is something wrong with PS's jpg size previewer. What version of PS are you using and under what OS?
Regards, Murray

Hi Murray,

I did as you suggested 1 when saving with the size of around 850x595. Opened it on IE browser and funny enough it had 1.2 MB size but the quality of <1>. I use CS5 Windows 7 home premium.
Thanks Neb

[mistermonday]

Neb, when you save a file (850x595) as a jpg, the file size as viewed with Windows Exporer, will be much smaller than 1.2M depending on the Quality setting. HOWEVER, when that file is opened in PS or IE or any any other application, the file becomes uncompressed and will be expanded to 850 x595 x3 bytes (plus a number bytes for metadata). One analogy I can give you is as follows: You squish / crunch a newspaper page so you can fit it in your shirt pocket (3x3 inches. When you take it out to read it, you open it back up to 20 x 17". The more you crunch it up, the more creases it will have and the worse will be how it looks when you unravel it. Same with jpg format. The more you compress, the more colors and detail get destroyed. Unlike the newspaper, with jpg you never recover the lost info - it's gone. That's why jpg is destructive.
Regards, Murray

[nebulaoperator]

Murrey,

I did experiment to see if that file would upload on RP with the lowest possible quality that is possible. PS, Windows properties all of thgem show same 1.2 MB size file. RP allowing up to 100KB so I gave ago and same thing here it showed 1.2MB . I regularly save files but never had anything like this. It is Jpeg it is compressed I know I loose quality but I don't get anywhere with this file for some reason. I was saving tons of files for the last 3 days and all went smooth. Seems I am stuck here for a while
Thanks Murrey

[mistermonday]

Can you upload the full sized orig jpg file somewhere along with a version that you have saved at low quality?
regards, Murray

[nebulaoperator]

original is RAW if that what you mean by original. thanks Neb

[Chain]

It is possible that a bunch of metadata is attached to the file (from plugins, other applications, etc.). This will not be lost when doing Save As.

If you are making a low resolution JPEG, then "Save for Web" is the best option as it will help you throw away needless information, and it gives you better control. Effectively you will end up with less file size compared to image quality. Try this and report back on the file size.

If possible, upload a copy of the problematic file so we can look at it and find out for sure.

Ps: I have run into this here at work where our InDesign-documents have a plugin that - among other things - embeds a large preview in the metadata. This metadata remains when exporting to PDF/JPEG (adding ~1 MB). If opening the PDF in Photoshop and using "save as" to JPEG the info still remains, making it impossible to get a smaller file size without removing the metadata (through save for web or File>file info>Advanced).

[Chain]

Original is raw? Hmm... strange.

I recommend you do as Murray suggest and upload the files to us so we can study them. It probably won't take long for Murray to figure it out if he gets his hands on the files

[nebulaoperator]

That was great tip Chain. My last update on this photo included plug-in and that caused the problem I believe. I used BatchPurifier and deleted all possible data of the file. Now I have all control over the <save as> process. What is that data for there anyway? I hope one's I delete it my file stays the same in a appearance(not that I notice) Thanks

[Chain]

Metadata of note on images usually consists of information like when or where it was taken, camera model and settings, copyright information, keywords, raw conversion settings, etc.

This usually doesn't take up much space, but when sharing it you usually want to remove the unesscesary stuff (privacy and file size considerations). Save for web helps you do this (it will not affect the pixels themselves in any way).

Plugins (and other programs) can also add whatever metadata they want, like my thumbnail example. This metadata is usually not understood by other programs (and ignored), but will follow the file until removed.

[nebulaoperator]

it is so stupid 1MB of meta was on for a while with the file. Next time I want to tip someone Nice one Chain

[mistermonday]

Neb, the easiest way to get rid of the metadata is: Open the image, do all your edits, resize, then Select All, Copy, Ctrl N (new doc), Paste. This will copy only the pixels to the new file; all of the metadata is gone.
Regards, Murray

[nebulaoperator]

Never done this one in the mind having what you said Murrey. Are you talking about PSD file too?

[mistermonday]

When you do copy and paste into a new document, the metadata is stripped off and you can save the file as a PSD, Tiff, JPG, BMP, or anything you like. If you are using a color managed workflow and wish to maintain your your color info, you just need to select the appropriate color space from the New Doc dialog window. If your image happened to be in a different color profile from your PS workspace, you could just use the Edit>Assign Profile command after you paste it into the new document.
Regards, Murray

[Chain]

Yep, creating a new document (without additional metadata) and copy/pasting works since you copy just the pixels and nothing else. That is a quick/easy way of stripping it.

If all you wanted was to save a lowres JPEG without the metadata, then skipping this step and going straight to "Save for web and devices" is quicker.

A slower way of removing metadata (but allows you to be selective about it, and you won't have to move things to a new document) is doing it under File > File info. In the advanced-tab you can view/delete any metadata (e.g. the metadata from the plugins as this won't show up in the predefined tabs).

[nebulaoperator]

Thanks Murray. Thanks Chain. Great help from you.
I red my self in forums about "Save for Web" and people say stay away from it. Personally it would give me wider color shift from normal <save as> way of saving
Are you aware of it in your experience?

[Chain]

What color profile is the image you are trying to save, and what are you going to use the lowres JPEG for?

[nebulaoperator]

sRGB. The lowres I use here of up to 100kb and then I use of up to 800kb to display it on the web or large one for a client.

[Chain]

If your image is in sRGB there should be no problem to use Save for Web.

You can also choose to embed the profile in the image file (the "embed profile" option) to be sure other applications that support colour management display it as intended.

[nebulaoperator]

Hi chain,

Thanks for the tip.

Have you ever tried to compare images side by side <save as> with <save for web>? They differ from each other. I am sure you did in the past. Does it make difference on what browser preview image?I mean do different browsers output same color when same image previewed?

[Chain]

In general, software like ms office, mail clients, and browsers (some do have cm support now, but you can not expect the end user to have it) ignore what profile an image has and will just display the numbers the way they are (should look like it was assigned srgb). This is regardless of how it was saved. I could run some tests but am on the metro now :p

Save for web will let you preview the image under different scenarios - try it. And make sure the image is srgb or it is guaranteed to look bad in many browsers.

[nebulaoperator]

Thanks Chain,

try it both ways and you will notice the difference.We still waiting for the reception in UK tubes though

[John Wheeler]

Hi Nebula

I will toss in a few more thoughts on browsers and color management. I leverage this from a post I made on another forum.

There are a couple things a browser needs to do to be color managed.

1) Be able to read ICC profiles tagged with the image
2) Be able to convert/translate the data to your monitors ICC profile

Some browsers do not do #1 and just assume that the data is already in sRGB. Some browsers do no color management at all and do not covert the data to match your monitors ICC profile and just set the raw image data directly.

Since you have no control of what browser a user has nor whether they have a color calibrated monitor, it is safest to convert to sRGB for web use. I also always make sure the image is tagged with its ICC profile even if it is for Web use with the assumption it is RGB.

Here is the cut and paste from my post on the other forum. The embedded links may be a little out of date yet provide good info:
--------------------------------------------------------------------

I am not the color expert yet to have colors match on a PC and Mac for web is Browser dependent and whether they are color managed Browsers or not (which is not necessarily consistent from Windows to OSX).

Without using color managed applications you need to make sure that all web images are output in sRGB color space whether tagged or not which is pretty standard given that many Browser are not color managed.

Here are a couple links that may be of help.

This first goes to one of many web pages available to test to see if your browser is color managed (Firefox and Safari are pretty good at this BTW where Internet Explorer in general has not):

http://www.gballard.net/psd/go_live_...Gprofiles.html

This second link is to a summary of several browsers across Windows and OSX and when they are color managed vs if the ICC profile is embedded or not:

http://blogs.whattheythink.com/blogn...n-web-browsers


Here would be my general rules of thumb and other experts may jump in with other views to get matched colors on web images with #1 being most desirable and going to #4 being least desirable.

1) Output with sRGB color space with profile tagged in images
2) If not #1, output with sRGB color space untagged with image
3) Outputting web images with color profiles other than sRGB (e.g. Adobe RGB) will only work well with color managed browsers if the image is tagged with the profile
4) Outputting web images with color profile other than sRGB with the image untagged virtually guarantees it will be viewed incorrectly (since untagged is typically assumed to be sRGB by the Browser).

This may not be 100% accurate yet should get you going. Others may jump in on the topic.