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10/12/2017 09:33:45 PM · #1
irfanview-image-properties.jpg?ssl=1&w=450

I have a problem very early on in my workflow. It is a compression problem. I think that I could be using the wrong program to open my original images on my SD card. I shoot JPEG.

I insert the SD card into my laptop, and then I open the folder on the card containing the images. I open an image in the SD card folder then view the Image properties.

The IrfanView Image properties indicate that compression has already been applied.
Is there a way that I can avoid that initial compression?

10/12/2017 10:11:14 PM · #2
JPEG is by definition a compression algorithm. EVERY JPG file is compressed. The amount of compression that happens depends on how much seamless unity (so to speak) there is in the image. Take a photo of a black card and check the out-of-camera size/compression; compression will be dramatic, filesize will be small. Now shoot something VERY intricate and with many colors (a jigsaw puzzle?) and check that; compression should be less and filesize larger. JPG works by comparing adjacent pixels and assigning them a value. The bigger the blocks of same-as-neighbor-pixels, the more compression you get off the bat. So if you, conversely, apply scads and scads of compression to a detailed image, it will muddy the details by creating larger same-tonality areas. Or something like that :-)

In your camera settings, you can set desired JPG quality and that will affect how much compression will be applied.
10/12/2017 10:45:13 PM · #3
Originally posted by Bear_Music:

JPEG is by definition a compression algorithm. EVERY JPG file is compressed.


Thank you kindly for that. I am just a little concerned that my default setting of IrvanView, compresses my original by a massive amount. It reduces the Megabytes from 17 to about 8.

I am actually glad that you replied because I have read many of your previous posts about the subject and I know that you know a lot about compression
10/12/2017 10:46:20 PM · #4
not just compression but lossy compression. you lose something every time you save as jpeg.
10/12/2017 11:16:12 PM · #5
Originally posted by posthumous:

not just compression but lossy compression. you lose something every time you save as jpeg.


Correct it's irretrievable.
Is there another program that I should be using?

My image in camera starts off around 17 Megapixels and is reduced to about 7 Megapixels at the first point of compression.

I never get to see it at 17 Megapixels.
10/12/2017 11:20:14 PM · #6
If I shoot JPEG does that mean that it is compressed right off the bat?
10/12/2017 11:26:47 PM · #7
You are confusing megaPIXELS with megaBYTES -- they are not the same thing. Megapixels refers to the number of discrete "dots" making up the image and will not change unless you resample the image. The number of megabytes it takes to describe and record those pixels to disk can vary markedly depending on the combination of image complexity and degree of compression.

As an experiment, take or make an image and save copies at several different JPEG compression levels and see how different the file sizes are even though the number of pixels is exactly the same. Then make two images the same size, but one with big blobs of flat color and the other full of lines and gradients, and save both at the same JPEG level and compare the file sizes on disk.
10/12/2017 11:27:04 PM · #8
I am not actually saving a file, I am just opening an image in the SD card folder.
10/12/2017 11:29:53 PM · #9
Originally posted by johnbrennan:

I am not actually saving a file, I am just opening an image in the SD card folder.

The camera is saving the file. Once you open it from the card you should save it in Photoshop or TIFF format (or the native format of your software if not PS) and do all your editing on that version; do not save as JPEG again until saving the final print/posting image.

I'm suggesting you make some experimental images from scratch -- you don't need a camera to test this out.
10/12/2017 11:37:52 PM · #10
Originally posted by GeneralE:

You are confusing megaPIXELS with megaBYTES -- they are not the same thing.


Yes, Paul, I think I am confusing Megapixels with Megabytes.

In-camera if I started off with 17.2 Megapixels, are you saying that at that point Megabytes are not measured because it is not yet a file?
10/12/2017 11:45:19 PM · #11
Originally posted by GeneralE:

Originally posted by johnbrennan:

I am not actually saving a file, I am just opening an image in the SD card folder.

The camera is saving the file.


Paul, If the camera saves the file as a jpeg then I am actually seeing a compressed image.
Is there a way that I can see a non-compressed image?
10/13/2017 12:06:05 AM · #12
Originally posted by johnbrennan:

Paul, If the camera saves the file as a jpeg then I am actually seeing a compressed image.
Is there a way that I can see a non-compressed image?

Yes. Shoot RAW+JPG and then you have a JPG for convenience and an uncompressed RAW to see the difference. You really OUGHT to be processing from RAW on basic principles.
10/13/2017 12:16:20 AM · #13
Originally posted by Bear_Music:

Shoot RAW+JPG and then you have a JPG for convenience and an uncompressed RAW to see the difference. You really OUGHT to be processing from RAW on basic principles.


If I shot RAW, what would I see when I view my SD Card Folder on my laptop?
Do I see a RAW file?

In other words when you "move" your images to your "images - originals" what are they saved as?
10/13/2017 12:46:01 AM · #14
Originally posted by johnbrennan:

In other words when you "move" your images to your "images - originals" what are they saved as?

They are stored (not "saved") as whatever they are called out of the camera. Canon RAW files are .CR2, Nikon are .NEF, mny Sony shoots .ARW, and so forth and so on. Your Irfanview, if it is up to date, will be able to read all RAW formats. Typically, RAW images don't look as "nice" as JPGs straight out of camera, because they are very neutral, leaving the final processing to the photographer, whilst JPGs have a certain level of contrast, saturation, sharpness, etc etc built in by the camera manufacturer to "look good" right out of the camera for people who shoot 'n post/print without editing. Also, you can apply image "styles" in-camera with JPG, which you can't with RAW.

But with RAW, which you process in a RAW processor before going to Photoshop or whatever else you use, you can experiment with ALL those camera styles, and way more, without corrupting the file in any way at all.
10/13/2017 01:31:21 AM · #15
Originally posted by Bear_Music:

RAW images don't look as "nice" as JPGs straight out of camera, because they are very neutral, leaving the final processing to the photographer, whilst JPGs have a certain level of contrast, saturation, sharpness, etc etc built in by the camera manufacturer to "look good" right out of the camera for people who shoot 'n post/print without editing. Also, you can apply image "styles" in-camera with JPG, which you can't with RAW.

But with RAW, which you process in a RAW processor before going to Photoshop or whatever else you use, you can experiment with ALL those camera styles, and way more, without corrupting the file in any way at all.


Thank you kindly for the information about RAW. I think for the moment that I'll stick with shooting JPEG. Even though I use Photoshop Elements, part of my editing is done by the JPEG process. Further down the track, based on what you described, I shall revisit the possibility of using RAW.

Once again I thank you, 30861.gif Bear_Music,1031.gif GeneralE and 21.gif posthumous for your help.
10/13/2017 10:04:09 AM · #16
John, my point would be, set the camera to record BOTH going forward, continue to use the JPG as always, but you have the RAWs to start the learning process with. You can use RAW with Elements.
10/14/2017 06:07:49 AM · #17
Oh, I see... record both RAW and JPG. I did not think that you could do that.

Are you saying set RAW in camera, store as a file on my 2 terabyte external hard drive and save as JPEG?

Is that the process?
10/14/2017 11:22:08 AM · #18
Originally posted by johnbrennan:

Oh, I see... record both RAW and JPG. I did not think that you could do that.

Are you saying set RAW in camera, store as a file on my 2 terabyte external hard drive and save as JPEG?

Is that the process?

No. In your camera settings menu, where you set "quality", you can specify various different levels of JPG compression to be applied (they'll have names like "fine" "standard" or whatever) AND you can set the camera to record RAW, OR you can set it to record RAW + JPG AND (if I am not mistaken, depends on camera) you can specify the quality of JPG to record alongside RAW. The camera will write two files for each exposure; a RAW file and a much smaller JPG file. This is the setting I use when I am shooting for Minimal Editing or when shooting a social event. I never shoot JPG alone except with my phone cam because I haven't figured out how to make the RAW setting stick :-)
10/14/2017 11:38:23 AM · #19
Originally posted by Bear_Music:

...except with my phone cam because I haven't figured out how to make the RAW setting stick :-)


If the S8 cam software is similar to the S7, setting to RAW when in "Pro Mode" should be sticky. Catch is, the cam will default to "Auto Mode" every time it's started, so trick is to re-invoke Pro Mode each time you launch the camera and you should have RAW again. One thing to watch, I know this is true of the S7, it doesn't save RAW files to the Micro SD card, only to the device itself. That's kind of a pain.
10/14/2017 04:45:20 PM · #20
On topic, this article and video describes exactly why I shoot in RAW and process in 16bit. I don't save as a JPEG for DPC purposes until the last step.
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