Posted by Barbara Graham on September 8, 2010 at 4:38 AM
First, I've done a search here for "sizing" and read through the posts there and tried the suggestions I'm able to try with Photoshop Elements, but the quality of some of my resized images (not all) remains the same, which is to say with an immense amount of detail lost.
I've just become aware of this tonight when I for some reason looked at my resized images full screen. I never have done that before. I've just posted them. The first resized image I looked at that had a problem I could say I was horrified. If I'm brave enough, I'm going to go back through the resized images I've posted and see what they look like.
I will try other search terms to see if I see other information and other things to try, but I also wanted to ask if anyone has seen this with their images and been able to resolve it. The 500KB versions are not horrifying, but they are not nearly as detailed as the original image. Some of the 200KB versions are, as I said, horrifying, and some are just boring compared to the original.
Also, I've seen that some or most of you recommend using Save for Web. I've read other places that Save for Web actually loses quality. Is that true in your experience?
Again, I'm using Photoshop Elements and not Photoshop CS5. Elements has much of the functionality of Photoshop, so if you give me Photoshop suggestions they might translate.
Right now I'm kind of stunned and feel a bit like this guy: But I know it's just a matter of learning.
Thank you all for your continued help. I so greatly appreciate it.
Posted by Nathan Buck on September 8, 2010 at 11:14 AM
Hi Barbara.
I use Photoshop Elements for my processing. Any time that you go from a RAW or a loss-less file type (like Tiff) you are going to lose some detail. Minimizing that loss of detail is the goal. From what I understand with 'Save for Web' there is meta-data that is not embedded in the photo, therefore saving those extra KB of data for image data instead of the meta-data.
I always use Save for Web, and I honestly have not been 'horrified' by the look of my photos after downsizing. One issue would be, however, that many of my flora images are not packed with detail as other types of shots might be.
One other thought. When you view the image full size, is the image actually being displayed at a greater than 100% magnification? When I view my images after resizing, I always 'View actual pixels'. This guarantees that I am not viewing at some large magnification. Also, from what I understand is that viewing a photo in Photoshop at magnifications like 25%, 50%, 75%, 100%, 125%, etc. is better than viewing at magnifications like 33%, 66%, etc. because of the way that the image is rendered by Photoshop.
Just some thoughts off the top of my head.
Nathan
Posted by David Bostedo on September 8, 2010 at 11:22 AM
The first resized image I looked at that had a problem I could say I was horrified.
Barbara - There's nothing wrong with your files, other than the fact that you're looking at them very large. When you resize a file to 720 pixels on the long side, as with a post, you're throwing away a lot of info and data. Viewing it "full screen" means that each pixel of the image will take up several pixels of your monitor and is guaranteed to look bad.
That's the whole point of re-sizing and getting a smaller file size - you are reducing the number of pixels used, and the amount of info. If you could do that, and still keep all the detail in the original file, no one would ever care about larger files.
Even if you take your full size original files, and view them at, say, 200% or more, you'll see something very similar. You can simply take an image and view it larger and have it look just as good.
In short, if the file looks good at 100% then that's the best you can do.
Posted by Lon Overacker on September 8, 2010 at 11:59 AM
I've just become aware of this tonight when I for some reason looked at my resized images full screen.
Barbara - can you clarify what you mean? "full size," in Photoshop? your web browser? and what are you doing to make it "full screen." David and Nathan are referring to 100% view in PS or Elements. It almost sounds like you have a 720px image that you are filling your monitor screen with, which would mean it's possibly at a 200% view or higher.
Using "Save-As" or "Save for web" are no different in terms of data loss. In fact those actions have nothing to do with data loss - it's the type of file you're saving that determines data loss. JPG is a compression algorithm that allows a file size to be much smaller than the original data. Where as TIF, PSD and others are what is called "loss-less" compression and data bits are not discarded.
Perhaps the biggest factor in losing data when resizing is the image itself. If you have an image let's say that is 100% clear blue sky, this image will compress very nicely and will compress to a very small image file because all the pixels are the same (generally speaking) and the compression algorithm can throw away lots of similar pixels to save space. Conversely if you have an image with lots of variation in color, tone and details, (like your "busy butterfly" or "live oak") these images will have more "data" and much fewer pixels can be discarded when compressing; thus much larger file sizes. AND you have to reduce your jpg quality much further to get below that 200k.
A couple options you have:
1. Make the image slightly smaller - say 700px or 680 or 650 if you have an image with lots of detail
2. You can host your image on another site and provide a url link to the image in the "post a photo" page. This way you can avoid the 200kb file size limit.
Posted by Ronnie Gaubert on September 8, 2010 at 12:04 PM
Hi Barbara,
Not sure about Elements but in photoshop there are 3 viewing choices at the top of the page.
ACTUAL PIXELS, FIT ON SCREEN AND PRINT SIZE.
If you are clicking on FIT ON SCREEN that could be your problem. Like Nathan stated above, you should be clicking on "ACTUAL PIXELS".
Ronnie
Posted by Richard Ditch on September 8, 2010 at 12:11 PM
I'll second David's comments. No image is intended to be viewed at greater than 100%. Judge your images at 100% view for whatever pixel dimensions you have set (720 and 1200 for NPN posting).
Resizing an image (downsizing) to make the pixel dimensions smaller tosses out lots of information and detail, and "stretching" those pixels to full screen cannot bring back the detail tossed out.
Compressing an image as a jpeg is a completely different process and works differently. It is not used to reduce the pixel dimensions of an image. Instead, it "smoothes" similar pixels that are close together and replaces individual RGB values for each pixel with an average RGB value for a group of pixels: the more you compress the more pixels are averaged. Compression works well in an image that has lots of clean/smooth areas; it does not work well when there's lots of fine detail in most of the image. You will begin to see "compression artifacts" where there are sharp transitions in the detail in an image.
"Save for web" and "Save as jpeg" do the same jpeg compression. Save for Web deletes the EXIF and color profile of an image by default to make the file size (KB) smaller and allows you to set a target size like 200KB for the compression. I don't use Save for Web because I want the EXIF data to stay with the file.
Don't confuse downsizing with jpeg compression.
Posted by Barbara Graham on September 8, 2010 at 12:33 PM
Thank you so much, everyone. I'm still at a stage where my images need all the help they can get, so this will help me a great deal in knowing what's really happening. Thank you again!
Posted by Gary Minish on September 9, 2010 at 12:08 AM
Barbara, a little bit of math will tell you why your small images don't look so good when you zoom in too far. My camera makes jpeg photos that are 3888 pixels by 2592 pixels. If you multiply those dimensions you get an image that contains 3888x2592=10,077,696 pixels (thus the term 10 megapixels or 10 million pixels). If I shrink one of those photos to the NPN display requirements I now have an image that is 720 pixels by 480 pixels. The image now contains 720x480=345,600 total pixels. If you divide 345,600 pixels by 10,077,696 pixels you will get 0.034 or 3%. The bottom line is that by shrinking my photo to 720 pixels on the long size I have removed 96.6% of my image! If you literally erase 99.6% of an image it shouldn't be surprising that it doesn't look very good if you look too close!!
Discussion
7 repliesI've just become aware of this tonight when I for some reason looked at my resized images full screen. I never have done that before. I've just posted them. The first resized image I looked at that had a problem I could say I was horrified. If I'm brave enough, I'm going to go back through the resized images I've posted and see what they look like.
I will try other search terms to see if I see other information and other things to try, but I also wanted to ask if anyone has seen this with their images and been able to resolve it. The 500KB versions are not horrifying, but they are not nearly as detailed as the original image. Some of the 200KB versions are, as I said, horrifying, and some are just boring compared to the original.
Also, I've seen that some or most of you recommend using Save for Web. I've read other places that Save for Web actually loses quality. Is that true in your experience?
Again, I'm using Photoshop Elements and not Photoshop CS5. Elements has much of the functionality of Photoshop, so if you give me Photoshop suggestions they might translate.
Right now I'm kind of stunned and feel a bit like this guy:
Thank you all for your continued help. I so greatly appreciate it.
I use Photoshop Elements for my processing. Any time that you go from a RAW or a loss-less file type (like Tiff) you are going to lose some detail. Minimizing that loss of detail is the goal. From what I understand with 'Save for Web' there is meta-data that is not embedded in the photo, therefore saving those extra KB of data for image data instead of the meta-data.
I always use Save for Web, and I honestly have not been 'horrified' by the look of my photos after downsizing. One issue would be, however, that many of my flora images are not packed with detail as other types of shots might be.
One other thought. When you view the image full size, is the image actually being displayed at a greater than 100% magnification? When I view my images after resizing, I always 'View actual pixels'. This guarantees that I am not viewing at some large magnification. Also, from what I understand is that viewing a photo in Photoshop at magnifications like 25%, 50%, 75%, 100%, 125%, etc. is better than viewing at magnifications like 33%, 66%, etc. because of the way that the image is rendered by Photoshop.
Just some thoughts off the top of my head.
Nathan
Barbara - There's nothing wrong with your files, other than the fact that you're looking at them very large. When you resize a file to 720 pixels on the long side, as with a post, you're throwing away a lot of info and data. Viewing it "full screen" means that each pixel of the image will take up several pixels of your monitor and is guaranteed to look bad.
That's the whole point of re-sizing and getting a smaller file size - you are reducing the number of pixels used, and the amount of info. If you could do that, and still keep all the detail in the original file, no one would ever care about larger files.
Even if you take your full size original files, and view them at, say, 200% or more, you'll see something very similar. You can simply take an image and view it larger and have it look just as good.
In short, if the file looks good at 100% then that's the best you can do.
Barbara - can you clarify what you mean? "full size," in Photoshop? your web browser? and what are you doing to make it "full screen." David and Nathan are referring to 100% view in PS or Elements. It almost sounds like you have a 720px image that you are filling your monitor screen with, which would mean it's possibly at a 200% view or higher.
Using "Save-As" or "Save for web" are no different in terms of data loss. In fact those actions have nothing to do with data loss - it's the type of file you're saving that determines data loss. JPG is a compression algorithm that allows a file size to be much smaller than the original data. Where as TIF, PSD and others are what is called "loss-less" compression and data bits are not discarded.
Perhaps the biggest factor in losing data when resizing is the image itself. If you have an image let's say that is 100% clear blue sky, this image will compress very nicely and will compress to a very small image file because all the pixels are the same (generally speaking) and the compression algorithm can throw away lots of similar pixels to save space. Conversely if you have an image with lots of variation in color, tone and details, (like your "busy butterfly" or "live oak") these images will have more "data" and much fewer pixels can be discarded when compressing; thus much larger file sizes. AND you have to reduce your jpg quality much further to get below that 200k.
A couple options you have:
1. Make the image slightly smaller - say 700px or 680 or 650 if you have an image with lots of detail
2. You can host your image on another site and provide a url link to the image in the "post a photo" page. This way you can avoid the 200kb file size limit.
Lastly, if you haven't found it already, take a look at the article on NPN from Darwin Wiggett.
Hope this helps,
Lon
Not sure about Elements but in photoshop there are 3 viewing choices at the top of the page.
ACTUAL PIXELS, FIT ON SCREEN AND PRINT SIZE.
If you are clicking on FIT ON SCREEN that could be your problem. Like Nathan stated above, you should be clicking on "ACTUAL PIXELS".
Ronnie
Resizing an image (downsizing) to make the pixel dimensions smaller tosses out lots of information and detail, and "stretching" those pixels to full screen cannot bring back the detail tossed out.
Compressing an image as a jpeg is a completely different process and works differently. It is not used to reduce the pixel dimensions of an image. Instead, it "smoothes" similar pixels that are close together and replaces individual RGB values for each pixel with an average RGB value for a group of pixels: the more you compress the more pixels are averaged. Compression works well in an image that has lots of clean/smooth areas; it does not work well when there's lots of fine detail in most of the image. You will begin to see "compression artifacts" where there are sharp transitions in the detail in an image.
"Save for web" and "Save as jpeg" do the same jpeg compression. Save for Web deletes the EXIF and color profile of an image by default to make the file size (KB) smaller and allows you to set a target size like 200KB for the compression. I don't use Save for Web because I want the EXIF data to stay with the file.
Don't confuse downsizing with jpeg compression.