Do raw image files have compressed data? (Page 2): I have the same choices on my D7100.

adamsg Loc: Chubbuck, ID

I have the same choices on my D7100.

SuperflyTNT Loc: Manassas VA

camerapapi wrote:

First thing first, RAW is not a file but data. RAW... (show quote)

RAW data is pretty useless unless it’s stored in a file.

SuperflyTNT Loc: Manassas VA

f8lee wrote:

JPEG, by its nature, i is /i a compressed data s... (show quote)

RAW or raw, (I’m not gonna pick nits over that), certainly IS an image file. It’s just a proprietary file format dependent on the make and model of camera. The difference with jpeg is that it’s a standard format that is useful to many platforms because they contain the information to decode the file and map it to pixels on the screen.

f8lee Loc: New Mexico

SuperflyTNT wrote:

RAW or raw, (I’m not gonna pick nits over that), certainly IS an image file. It’s just a proprietary file format dependent on the make and model of camera. The difference with jpeg is that it’s a standard format that is useful to many platforms because they contain the information to decode the file and map it to pixels on the screen.

This is incorrect. As I have already stated endlessly in this forum:

An image file is one where each pixel (picture element) has an assigned RGB value. Get it? Whether it's PNG, PSD, JPEG, TIFF or any of the other image file formats, in every case (every case) every pixel has an RGB value. Compressed, uncompressed, 8-bit or 14 bit depth, every pixel has a specific RGB value.

A raw file does not. Learn how every digital imaging sensor, save for the Foveon and the Leica Monochrom, works. Each photo site (when you see a spec of 24 megapixels, what that refers to is the chip has a grid of 6000 x 4000 photo sites) has a colored filter above it in a Bayer pattern, or in the Fuji X-Trans, a variant thereof. That means that the photo site at location 20,20 will record only the red photons that have passed through the red filter above it, while it's neighbor, with a green filter, is only counting the green photons. And so on, ad nauseum.

Not until those red and green and blue photon counts are reviewed (along with readings from sites that might be one row or column away) is a specific RGB value ascribed to a given pixel.

Read that sentence again.

So, a raw file is not an image file since each pixel is not, in fact, assigned an RGB value until it is processed (demosaiced).

Now, if every computer system were perfect then an image file would always look identical no matter where it is displayed, since RGB value of 100,200,100 will always be a very specific color. There is a look-up table for just that purpose.

But the same raw file may be demosaiced by different programs (Adobe ACR/LR, Capture One, the camera manufacturer's own, Apple OSX, etc.) may be interpreted into slightly different tones when it is demosaiced. Now, Capture One won't turn an area blue that Lightroom shows as red, of course, but there can well be (and many pros argue, are) subtle differences between their outputs. There simply is no lookup table for what color one should get if one photosite counts 1000 red photons and it's neighbor counts 300 blue photons, etc.

So, to repeat for the 10th time - a raw file does not have specific RGB values at each pixel, not until it is demosaiced.

And the reason each camera (even from the same manufacturer) has a different raw file is because the file is generated from the photosites, which may differ from one model to the next. So even though all Nikon raw files are appended .NEF unless you have the demosaicing program for the D850, your program that works for the D800 or whatever will not work.

Get it?

SuperflyTNT Loc: Manassas VA

f8lee wrote:

This is incorrect. As I have already stated endlessly in this forum:

An image file is one where each pixel (picture element) has an assigned RGB value. Get it? Whether it's PNG, PSD, JPEG, TIFF or any of the other image file formats, in every case (every case) every pixel has an RGB value. Compressed, uncompressed, 8-bit or 14 bit depth, every pixel has a specific RGB value.

A raw file does not. Learn how every digital imaging sensor, save for the Foveon and the Leica Monochrom, works. Each photo site (when you see a spec of 24 megapixels, what that refers to is the chip has a grid of 6000 x 4000 photo sites) has a colored filter above it in a Bayer pattern, or in the Fuji X-Trans, a variant thereof. That means that the photo site at location 20,20 will record only the red photons that have passed through the red filter above it, while it's neighbor, with a green filter, is only counting the green photons. And so on, ad nauseum.

Not until those red and green and blue photon counts are reviewed (along with readings from sites that might be one row or column away) is a specific RGB value ascribed to a given pixel.

Read that sentence again.

So, a raw file is not an image file since each pixel is not, in fact, assigned an RGB value until it is processed (demosaiced).

Now, if every computer system were perfect then an image file would always look identical no matter where it is displayed, since RGB value of 100,200,100 will always be a very specific color. There is a look-up table for just that purpose.

But the same raw file may be demosaiced by different programs (Adobe ACR/LR, Capture One, the camera manufacturer's own, Apple OSX, etc.) may be interpreted into slightly different tones when it is demosaiced. Now, Capture One won't turn an area blue that Lightroom shows as red, of course, but there can well be (and many pros argue, are) subtle differences between their outputs. There simply is no lookup table for what color one should get if one photosite counts 1000 red photons and it's neighbor counts 300 blue photons, etc.

So, to repeat for the 10th time - a raw file does not have specific RGB values at each pixel, not until it is demosaiced.

And the reason each camera (even from the same manufacturer) has a different raw file is because the file is generated from the photosites, which may differ from one model to the next. So even though all Nikon raw files are appended .NEF unless you have the demosaicing program for the D850, your program that works for the D800 or whatever will not work.

Get it?

This is incorrect. As I have already stated endles... (show quote)

Wow, you are a nit picker. Where do you get the rule that an image file has to have an RGB value assigned to each pixel? Yes for standard image files that are displayed by many standard programs that may be true, but any file that contains image data is an image file. How that data is stored is immaterial as long as it can be translated and displayed by whatever software is designed for it. Just because a format is proprietary doesn’t mean it’s not an image file.

rehess Loc: South Bend, Indiana, USA

f8lee wrote:

This is incorrect. As I have already stated endlessly in this forum:

An image file is one where each pixel (picture element) has an assigned RGB value. Get it? Whether it's PNG, PSD, JPEG, TIFF or any of the other image file formats, in every case (every case) every pixel has an RGB value. Compressed, uncompressed, 8-bit or 14 bit depth, every pixel has a specific RGB value.

A raw file does not. Learn how every digital imaging sensor, save for the Foveon and the Leica Monochrom, works. Each photo site (when you see a spec of 24 megapixels, what that refers to is the chip has a grid of 6000 x 4000 photo sites) has a colored filter above it in a Bayer pattern, or in the Fuji X-Trans, a variant thereof. That means that the photo site at location 20,20 will record only the red photons that have passed through the red filter above it, while it's neighbor, with a green filter, is only counting the green photons. And so on, ad nauseum.

Not until those red and green and blue photon counts are reviewed (along with readings from sites that might be one row or column away) is a specific RGB value ascribed to a given pixel.

Read that sentence again.

So, a raw file is not an image file since each pixel is not, in fact, assigned an RGB value until it is processed (demosaiced).

Now, if every computer system were perfect then an image file would always look identical no matter where it is displayed, since RGB value of 100,200,100 will always be a very specific color. There is a look-up table for just that purpose.

But the same raw file may be demosaiced by different programs (Adobe ACR/LR, Capture One, the camera manufacturer's own, Apple OSX, etc.) may be interpreted into slightly different tones when it is demosaiced. Now, Capture One won't turn an area blue that Lightroom shows as red, of course, but there can well be (and many pros argue, are) subtle differences between their outputs. There simply is no lookup table for what color one should get if one photosite counts 1000 red photons and it's neighbor counts 300 blue photons, etc.

So, to repeat for the 10th time - a raw file does not have specific RGB values at each pixel, not until it is demosaiced.

And the reason each camera (even from the same manufacturer) has a different raw file is because the file is generated from the photosites, which may differ from one model to the next. So even though all Nikon raw files are appended .NEF unless you have the demosaicing program for the D850, your program that works for the D800 or whatever will not work.

Get it?

This is incorrect. As I have already stated endles... (show quote)

I don’t see any connection between this lecture and compression.

f8lee Loc: New Mexico

Okay, I give up.

Obviously you are incapable of understanding, and it is pretty arcane stuff, best left to people who know how things work. So I am tapping out, no sense trying to help the obstinate.

ta!

rehess Loc: South Bend, Indiana, USA

f8lee wrote:

Okay, I give up.

Obviously you are incapable of understanding, and it is pretty arcane stuff, best left to people who know how things work. So I am tapping out, no sense trying to help the obstinate.

ta!

Your ‘contribution’ has not been relevant to the material of this thread in any case.

TheShoe Loc: Lacey, WA

camerapapi wrote:

First thing first, RAW is not a file but data. RAW data is a more appropriate way to address it.

I believe that is generally understood that the phrase "raw file" is used, it means, "file that contains raw data." There is absolutely nothing wrong with this usage.

SuperflyTNT Loc: Manassas VA

f8lee wrote:

Okay, I give up.

Obviously you are incapable of understanding, and it is pretty arcane stuff, best left to people who know how things work. So I am tapping out, no sense trying to help the obstinate.

ta!

Yeah. I write software for a living. I get how arcane stuff works. Just because something is not a standard image file doesn’t mean it’s not an image file. Any file is a series of 1s and 0s that need to be interpreted by software and/or hardware. If those 1s and 0s can be interpreted to display an image it can be called an “image” file.

blackest Loc: Ireland

SuperflyTNT wrote:

RAW or raw, (I’m not gonna pick nits over that), certainly IS an image file. It’s just a proprietary file format dependent on the make and model of camera. The difference with jpeg is that it’s a standard format that is useful to many platforms because they contain the information to decode the file and map it to pixels on the screen.

Raw files are kinda like an image file as in flour is to cake. Each pixel site has a single color recorded. The values recorded need to be weighted and interpreted a contrast curve needs to be applied a choice of white point, black point and the relative position of tones in the image needs to be made. That's quite a long way from a jpeg file where each pixel has a color decided when you open the file.

raw files are i guess almost analogous to a latent image on a negative, how the film is processed will determine the negative image and then how the negative is exposed will determine the print.

Is a book a movie?

f8lee Loc: New Mexico

blackest wrote:

Raw files are kinda like an image file as in flour... (show quote)

Forget it - he is incapable of seeing what he is missing. Because, you know, he writes software for a living and all.

CHG_CANON Loc: the Windy City

If it quacks like a duck, and walks like a file, and you can browse it with most operating systems, it's probably a RAW file.

SuperflyTNT Loc: Manassas VA

f8lee wrote:

Forget it - he is incapable of seeing what he is missing. Because, you know, he writes software for a living and all.

SuperflyTNT Loc: Manassas VA

blackest wrote:

Raw files are kinda like an image file as in flour... (show quote)

Yeah, I bake too. And that’s a terrible analogy. As is the comparison to a latent I mage. To be made into a cake the flour must be transformed. Without even bringing the other ingredients into it, once flour is a cake it’s no longer flour. A latent image on a negative, once it’s developed is changed and will never be latent again. A raw file is able to be displayed as an image with absolutely no change to the file. Now I’ll concede that raw is not a standard image FORMAT, but the fact that it can be displayed without changing the file means it is an image file. And that’s what f8lee can’t see.