photoshop actions to resize files

[pushu]

I am trying to create an action in photoshop to resize my files for a pic2exe presentation.

Little did I realize how easy it was for someone to steal the images from a show. Now that I know better, I am taking the advice I have read from this forumn in the last year or two to protect my bottom line.

I am using kodak's photodesk as an image editor and my jpeg files start at 300 dpi. If I change the resolution to 72 dpi, the image becomes quite small so I am wanting to increase the image size to 1020x680 without changing the dpi. (or is this step not necessary?)

It is easy to create an action to do this but how can I make an action that tells the difference between a vertical image and a horizontal image? If I just say make all the heights to 1024, I makes the horizontals too large.

I also wanted to add a watermark that was a line of text (studio name repeated 3 times) which I was going to place across the bottom and across the top (harder for someone to crop out but not appear across someone's face). when I make this action and use a horizontal print as a template, the line of text will not be in the proper place on a vertical image. Maybe I just need to forget the second line of text?

[alrobin]

Pushu,

You need only consider the screen size (in pixels). Don't worry about the "dpi" unless you are wanting to print.

The best solution is to put all the verticals in one folder and the horizontals in another, and create 2 actions, one for each.

If you use IrfanView to resize the photos, I believe you can indicate both a vertical size and a horizontal size, and IrfanView will apply the appropriate dimension keeping everything in proportion.

[pushu]

AL:

If my goal is to prevent someone from stealing the images to make their own prints, wouldn't I want to reduce the dpi down to 72?

I don't think separating the vertical and horizontal prints would be my best choice as a typicall wedding show could contain 500-600 images. That could be quite time consuming to do that.

I have never used IrfanView. Is this the answer?

What about the option of fit image to screen? Is that not recommended?

[think(box)]

The term dpi refers to dots per inch. This makes sense when you are scanning as follows: A 5x7" print at 300 dpi will come out as 1500x2100 pixels. Just multiply inches times dpi (dots per inch) to get pixels. For your PTE presentations the screen settings of the computer used to display are in pixels, e.g. 1024x768 pixels. If your photo is 1024x768 pixels it will fill the screen completely. If you change that computer's screen to 1600x1200 pixels then the same 1024x768 photo will not fill the screen because it occupies only a fraction of the pixels. Never in this discussion did "inch" units matter. Scanning and printing are the only place where real world dimensions must be considered.

As for security, read the many recent topic threads. You can either make the pixel dimensions very small, like 800x600 or even less, or you can deface your image with studio name to protect it, or both. You can also use invisible forms of watermark that can be used to legally confirm a theft.

What about the option of fit image to screen? Is that not recommended?

Best answer is use Irfanview here. It can limit h and v resolution in a way that Photoshop can not do without using two sets.

[Ken Cox]

see

http://www.somewhere-in-time.net/tutorial/irfanview/

and

http://www.somewhere-in-time.net/tutorial/photoshop/

irfanview adheres to the KISS principle

ken

[pushu]

thanks for the info - I will download irfanview and give it a try.

Perhaps I am a bit confused about the image size/dpi issue?

should I not be at all concerned with the dpi? I have resized my images to 72 dpi and created a show. I must say the image quality is very poor. So poor that I'm not sure I want to give this to my customer. If I resized the images to1020x680 and compress the jpegs (and leave the dpi at 300) will this result in an acceptable image for the show that would not be a good print if someone did a screen capture?

[vhansen]

If you are using Photoshop 7, you can use the Scripting plug-in and create a Java script that will do everything you want, including determining if the image is vertical or horizontal, and acting on the information. It can also put a watermark on the images, resize, etc.

I have a few scripts I've written, and there are a few more out on the web.

If this is an option for you, and I can be of any assistance, let me know.

[Gérard de Lux]

Concerning the dpi/pixels, compression and related questions, you may find useful general information on these pages.

[think(box)]

Here is a little more pixel and dpi help:

The image resolution is purely a matter of the pixel dimensions unless your lens was out of focus

Think of pixel as "picture element". An 800x600 pixel photo has 800 picture elements horizontally and 600 picture elements vertically for a total of 800 times 600, or 480,000 pixels (one half of a megapixel). Each pixel has a unique color and luminance. There is no variation within a pixel. If you have very few pixels in a photo then it has very little detail or total content. If you have very many pixels in a photo then there can be a large amount of detail.

And now for dpi: Why you can set dpi for a given picture is related to how it will print. If you have an 800x600 photo, once again, and you use 72 dpi at time of printing, then this photo will take a sheet of paper that is 800/72 inches by 600/72 inches, or 11.1 by 8.3 inches. If you use 300 dpi at time of printing for same photo it will be sized to 800/300 inches by 600/300 inches, or 2.67 by 2 inches. In both cases there is exactly the same amount of detail in the paper print. But one print is larger than the other, and if that one is so large that pixels become visible individually, then it will appear to be poor in quality or too fuzzy if the pixels are smoothed by your printing software.

In conclusion, for PTE slideshows ignore dpi altogether. Don't even bother setting a value. Just pay attention to the pixel dimensions. It may help to make a test slideshow in which you look at a reduced pixel dimenion photo with PTE's enlarge to fit screen feature. If it looks poor and low-res, then you have probably reduced its resolution enough to make it unattractive for a theft target. And then when you look at the same photo in actual pixels (not fit to screen) it appears much smaller on the srceen, but looks fine!

[pushu]

If I understand this correctly... then the image that looks good on the screen will be small in size however making it larger to fill the screen will make it look of poor quality? We are talking about the same file here, correct?

If that is the case, is there no point at which the image will be of good or at least decent quality in the show - generally filling the screen with the image, but not be of enough quality to make it worth while to screen grab and print?

[alrobin]

... should I not be at all concerned with the dpi? ..........snip..........

If I resized the images to1020x680 and compress the jpegs (and leave the dpi at 300) will this result in an acceptable image for the show that would not be a good print if someone did a screen capture?

As Bill says, you need only consider dpi if you are scanning or printing. Since your images are already in digital form, you only need to worry about dpi if you are getting them ready for printing. Since you are putting them into a digital show, you don't need to worry about dpi at all. You usually have two options for changing image dimensions: one in pixels (this is the one you want to use here), and one in dpi. They are related in the imaging program in that changing one could have an impact on the other, depending on the way it is used. However, the one and only criterion you need to deal with if you are resizing for viewing on a monitor is the one which changes the dimension in pixels. If your monitor is set at 1024 x 768 pixels, then to fill the screen, the image has to be 1024 x 768 pixels in size, regardless of what the number for dpi is set at.

One other consideration in resizing: don't resize upwards in size unless there is no other option. Try to always use an original un-compressed tiff or bmp or psd file, larger than your desired image, as a starting point for editing.

The next consideration is compression ratio for your final image - the lower the value the poorer will be the image, but the smaller the file, as well. It will also give a poorer print, but it's a tradeoff, as you probably want a fairly good image for your show. Note that setting the dpi will have no bearing on the quality of the print here, as it can always be reset higher by your client if the image is large enough in pixels. It's a "Catch 22" situation, unfortunately, so the only alternative worth considering, as Bill has said, is to add a watermark.

[pushu]

I guess I am to used to ordering prints from the lab and can't seem to get away from the dpi mentality. I should be talking in ppi not dpi, right?

I have been watermarking the images, but don't want to end up with a copyright symbol over someones face. If I put the watermark out of the way, it can be cropped out. I guess I'm looking for an easy answer that doesn't exist.

Perhaps I am getting too hung up on worrying about the few who would steal the images?

thanks to all for the info... I shall do some reading

[alrobin]

Concerning the dpi/pixels, compression and related questions, you may find useful general information on these pages.

Gérard,

That's quite a handy summary of elementary digital theory.

[alrobin]

I guess I am to used to ordering prints from the lab and can't seem to get away from the dpi mentality. I should be talking in ppi not dpi, right?

I have been watermarking the images, but don't want to end up with a copyright symbol over someones face. If I put the watermark out of the way, it can be cropped out. I guess I'm looking for an easy answer that doesn't exist.

Perhaps I am getting too hung up on worrying about the few who would steal the images?

thanks to all for the info... I shall do some reading

No, Pushu, you still haven't got it!

When talking about images for the screen, you shouldn't use the term "inch" at all. Just the total number of pixels.

Just think of how many pixels you would need to lay, side by side, on the screen, to make up an image. Once you have set the resolution of your monitor, the "distance between pixels" is fixed, so if you want a big picture, you need 1024 pixels, for example, and if you want a small picture, you might need only 400 pixels. Think of them as just building-blocks. The number of pixels in an inch ("ppi") doesn't matter here. So it's just "pixels".

[think(box)]

Adding to Al's compression considerations, once again make a fullscreen test slideshow to see how it looks. Think of compression as another quality knob. For the same example 800x600 photo, the quality gets worse if the compression is greater. Adobe's scale value "0" is greatest compression. Irfanview's "Save Quality" value "1" is the greatest compression.

The only reason we ever bother with compression is because high compression means small file size. Unfortunately it also means lower image quality. We want the best tradeoff between the image quality and photo file size because today's computers and networks work better when photo files displayed or transfered, respectively, are smaller.

By the way, Adobe's save for web allows you to see the degradation for chosen compression value before you actually save to a file.

Update: ppi relates to the apparent sharpness on paper (pixels per inch). It is a good metric for knowing how much enlargement you can do before a given photo looks bad.

The watermark or studio credit should cover up something that they care about (but not someone's face!) for best protection. Of course the thief could crop the photo for the face.... So the resolution, if low, stems that avenue. Another option: If you use a degree of transparency in what you use to cover up content, then the photo is too hard to fix for the thief yet allows all content to be visible. In Adobe just use layers and set opacity.

[Truelight]

Want it --really-- simple?? I rarely see the need for images that are larger than 800x600 when making a PTE show. Yes, people use monitors with higher resolution and yes, there are projectors now that go higher than that, but if you use the "windowed" mode of PTE, you can work around the resizing issue. An 800x600 image will print very poorly at anything much above a 4x6" print, but will look OK on the screen. (DPI is meaningless to a screen capture program so 'reducing your images to 72dpi' means nothing here and if someone does want to steal your images, that's how they will do it). Keeping images small also has the benefit of making for leaner .exe files.

Now...(and we've all discussed this before)...If you are really concerned about someone stealing your images, there are only two solutions:

-1- Deal only with honest people. A determined thief will find a way to steal from you if that is their intent. No protection exists that can't be circumvented.

or

-2- Show your images, but don't distribute disks with the images or the shows on them. Yes, you can lower image quality, use watermarks, do any number of things, but remember point -1- above.

And finally.... If you're losing sleep over someone stealing -YOUR- images, you're 'holding on too tight.' All of us are just 'passing through' this life. Don't be so concerned with what you think you 'own.'

[alrobin]

And finally.... If you're losing sleep over someone stealing -YOUR- images, you're 'holding on too tight.' All of us are just 'passing through' this life. Don't be so concerned with what you think you 'own.'

Rick,

That's very good advice! I have to keep reminding myself of that all the time, too. You sure can't take them with you!

[Ken Cox]

an example of how things are "opening up" see

Look Inside Many of Our Books!

http://www.amazon.com/exec/obidos/tg/brows...9482085-2287017

they already have scanned in 150,000 books -- page by page

more today see

http://www.nytimes.com/2003/10/27/business...a/27amazon.html

I believe you must be a registered NY times web subscriber -- it is free

ken

[pushu]

I want to thank you all for the responses and links to all the great info. I spent yesterday making prints and shows at different sizes and resolutions and feel I have found what will work for me.

I know you are telling me to stop thinking in ppi/dpi terms but I do feel that is a consideration. My question all along was not what is the best file size for a show, but what is the best size for a good looking image for a show but not good enough to steal for printing. (perhaps I didn't word it clearly in the original post) . I can make the image quite small by pixels but if the dpi is left at say 300, the image can be made much larger in a program like photoshop and a good print can be made. Reducing the dpi, but keeping the overall size to 800x600 (or smaller) seems to be a good middle ground. What seemed to work best from my tests was an image of around 500x350 @150dpi (I know, here I go again) and saved at a jpeg compresion level of 5 (in photoshop) and use the fit screen option in pic2exe. would you think these choices are not good?

Another point to Think(box) ... you can make an action within photoshop that can resize the image and tell the difference between a vertical and horizontal. Under file>automate>fit image will keep proper porpotions.

(another thing I learned yesterday)

[alrobin]

What seemed to work best from my tests was an image of around 500x350 @150dpi (I know, here I go again) and saved at a jpeg compresion level of 5 (in photoshop) and use the fit screen option in pic2exe. would you think these choices are not good?

Pushu,

If you were asking me for my opinion, I would have to say "no".

First of all, images of only 500x350 pixels will not look their best in "fit to screen" mode on a monitor set at 1024x768.

Secondly, you are still persisting with the "dpi" idea. If you resize your images to 500x350, it won't matter what your dpi is set at - anyone can change that to whatever they want (within reason, of course) once they have captured your images. The fact that you have resized to 500x350, itself, will limit them considerably in their ability to print, regardless of the "dpi" setting. They are somewhat inter-related, but it's not the "dpi" setting that makes the difference in printability.

If you are going to consider dpi in an already-digitized image, then you also have to specify image size. You can easily set the dpi of your 500x350 pixel images to 1000, but the image size will only be a fraction of the size of a usable print. But if you set the dpi to 10, you will have quite a large print, albeit low-quality. The factor which determines the ability to produce a good print is the image size in pixels, not the dpi setting, since it can be changed by your client.

[pushu]

Al:

I guess I am still not grasping this whole concept of how the pixel size of the image and dpi are related but am going on the prints I made from test files. If I make the image size 1024x768 and leave it at 300dpi I can make a very nice print from this. even when I made the same image 600x400 and left it at 300dpi it makes a good print.

When I kept the image the same size but reduced the dpi to 150 it was still an acceptable print in my opinion to someone who could get it for free. When I resaved the files at a compression of 5 in photoshop I felt they then did not make a good print but were still ok for a show (just ok, not good)

Certainly someone can import an image into photoshop - that starts out at 10 or 100 or 200 dpi and make it whatever dpi or file size you wish, but the results from interpolating up an image will be of poor quality.

Is this not the case?

I don't mean to dwell so much on this dpi issue or make you think I am loosing sleep over someone stealing my images, as I don't think this happens that much. It's just that all my weddings are presented with pic2exe shows and I want make it more work than it's worth for the images to be printed, yet make the best show I can.

[alrobin]

Certainly someone can import an image into photoshop - that starts out at 10 or 100 or 200 dpi and make it whatever dpi or file size you wish, but the results from interpolating up an image will be of poor quality.

Is this not the case?

Pushu,

You are correct in that when you are printing, you have to consider dpi, and set it at whatever you need for your particular printer, depending, of course, on how large the image is in pixels, as this alone is what determines the practical limit for the dpi which can be used.

However, when you are changing the dpi for a print, unless you also change the size in pixels of the image, you are not "interpolating". It won't matter what dpi you set the image at, until you go to print, and then, as Bill said, your printer software will do any necessary interpolating to achieve that size of print.

But setting the dpi at 10 or 100, does not mean that the image will yield a poor print if someone else uses 200 dpi to print. Provided there are enough pixels in the image, (i.e. image size), someone else could change the dpi to 1000, and get an super print! Give it a try!

Always think in terms of pixels, not dpi, unless you are scanning or actually printing. But you are not doing the printing in this case - your client is, so let him or her worry about the dpi. If you don't want your image to be stolen, keep the image size small (in pixels, that is), or use a low compression ratio, or apply some sort of watermark, or use any combination of the three.

[LumenLux]

Pushu -

Just a little side thought.

The digital camera that I have used the most has 5 megapixel capability. I have printed "great" results to 20x30 inches. I have cropped and used a 1/4 area of photo to "great" 13x18 inches. All of these photos (files) when they are downloaded from camera memory to computer, show up as 72 dpi.

[pushu]

I think I now realize why I wasn't seeing what you all are trying to tell me.

When I was changing the dpi in photoshop, I had the resample box checked. So when I was changing the dpi, I was also altering the document size. That must be what was messing me up.

If I took an 800x600 image and changed the dpi to 10 (not resample) I now see that it doesn't affect the image. If I check the resample box, the file size changes. that was what I was baseing my testing on.

Thank you all for bearing with me. All of a sudden it make sense.