new to post processing

[Manfred M]

That's loaded in memory in a raster format, defined in 2 dimensions.

I believe that this is incorrect. Computer memory is linear, so it is one-dimensional. Memory addressing can be done either directly or through pointers to that memory location.

In your model for a pixel based editor is also incorrect. It is a 3-dimensional model. We know this because if we duplicate the base layer, the file size increases significantly as all the changes made to additional pixel layers are stored. This is why adjustment layers and layer masks are used as these take up significantly less storage space. This discounts the file overhead and any efficiencies of lossless compression the software may apply to the additional layer(s).

This screen shot from Photoshop shows the three-dimensional aspect. Each of the layers, in your parlance, is two-dimensional and there is a stack of 9 layers, so the data is really 3D.




The technical aspects don't really matter as the high level language hides those details from the programmer. My understanding is that the early versions of Photoshop were written in Pascal but the main code base was migrated to C++ many years ago. If someone has more up to date information, I would be interested in understand this. If I remember my C / C++ programming (the last time I used those languages was probably 30 years ago), pointers were much faster than matrices.

The difference is when you save your editing. A parametric program stores the parameters the functions has used, a non-parametric editor overwrites the original.

This is also not quite correct. The parametric editor does store the parameters used for each edit. In a pixel based editor each layer of the edit is also stored. That way when a file is opened each layer that has been worked on is exactly the same as when the edit was done. If a non-destructive workflow is used; adjustment layers, layer masks and SmartObjects, then the "Background Layer" does not change.

The fundamental difference between a parametric editor and a pixel based editor is that the former stores instructions on how to manipulate the data and the latter stores a stack of pixels and a stack of masks that impact the pixels below the mask.

Be warned. If we continue I show you a diagram.

Please don't. It is incorrect and clearly shows you do not understand how the different types of editors perform. As before, be forewarned, we may remove the diagram and add a disclaimer telling readers why this was done.

I hardly make use of an editor and when it's Gimp.

If this is good enough for you, then why would you do anything else. For some of us a parametric editor does not offer the control we need to turn out the images we want.

For many photographers the raw convertor with its parametric editor is the start of the editing process, not the end.

[george013]

I believe that this is incorrect. Computer memory is linear, so it is one-dimensional. Memory addressing can be done either directly or through pointers to that memory location.

In your model for a pixel based editor is also incorrect. It is a 3-dimensional model. We know this because if we duplicate the base layer, the file size increases significantly as all the changes made to additional pixel layers are stored. This is why adjustment layers and layer masks are used as these take up significantly less storage space. This discounts the file overhead and any efficiencies of lossless compression the software may apply to the additional layer(s).

This screen shot from Photoshop shows the three-dimensional aspect. Each of the layers, in your parlance, is two-dimensional and there is a stack of 9 layers, so the data is really 3D.




The technical aspects don't really matter as the high level language hides those details from the programmer. My understanding is that the early versions of Photoshop were written in Pascal but the main code base was migrated to C++ many years ago. If someone has more up to date information, I would be interested in understand this. If I remember my C / C++ programming (the last time I used those languages was probably 30 years ago), pointers were much faster than matrices.




This is also not quite correct. The parametric editor does store the parameters used for each edit. In a pixel based editor each layer of the edit is also stored. That way when a file is opened each layer that has been worked on is exactly the same as when the edit was done. If a non-destructive workflow is used; adjustment layers, layer masks and SmartObjects, then the "Background Layer" does not change.

The fundamental difference between a parametric editor and a pixel based editor is that the former stores instructions on how to manipulate the data and the latter stores a stack of pixels and a stack of masks that impact the pixels below the mask.



Please don't. It is incorrect and clearly shows you do not understand how the different types of editors perform. As before, be forewarned, we may remove the diagram and add a disclaimer telling readers why this was done.




If this is good enough for you, then why would you do anything else. For some of us a parametric editor does not offer the control we need to turn out the images we want.

For many photographers the raw convertor with its parametric editor is the start of the editing process, not the end.

You introduce here a lot of noise but you didn't go into my post.

What is the original file??? It's that disk file, a raw file or a jpg,tiff or whatever. That's loaded in memory in a raster format, defined in 2 dimensions. That's where the editing is done, in memory. The difference is when you save your editing. A parametric program stores the parameters the functions has used, a non-parametric editor overwrites the original. ONLY THEN.
Be warned. If we continue I show you a diagram.

We've discussed this before, but don't forget the difference between Save and Save As/Export. That you've a possibility to us a Save As or Export or something similar doesn't add anything to the fact that editing is done pixel based in memory, both in what you call a parametric based or pixel based editor.
The only converter that had a Save option, as far as I know, was Nikon CaptureNx. They stored the edit list and a full jpg in the raw file. That file was overwritten but not the raw data in it.

Just a few comments. Total of no interest for James and others.
Computer memory is lineair, so can't be 2 dimensional but if you use layers it becomes 3-dimensional and that is proofed for a file grows???? I don't know what file you mean and I don't understand the argumentation.

The fact that James is starting to shoot in raw is ok and I do advice that. The editing tools in most converters are more then enough to produce a good picture. A good picture has content, there's no need to clone parts of it or something like that. And in many converters there're possibilities for local adjustment in contrary to what you keep saying.
A more complex editor doesn't have make better picture, just as a more expensive camera doesn't take better pictures.

George

[xpatUSA]

While computer memory is linear as in one-dimensional almost by definition, data structures are not and images are structures of type array, the most common image type being 2D, often - but not necessarily - 3 columns of color data such as RGB by as many rows as are necessary to describe the image. It could be said that the introduction of layers introduces a third array dimension - but that would be stretching it, unless the layers are contiguous with the original image data; otherwise they are simply a collection of 2D arrays within the same file, IMHO. I might be wrong about that and maybe the answer to that is here:

https://en.wikipedia.org/wiki/Array_data_structure

Always good to have a credible reference in discussions like this . . .

[DanK]

James,

George wrote:

For you it's total irrelevant.

Exactly right. Not only is this digression irrelevant; it only obscures the answers to your question. Manfred and I have given you what I hope is a reasonably clear explanation of how parametric and pixel editors differ and why that matters in practical terms. If anything we wrote is unclear, please ask.

If you want to continue shooting raw, which I would advice, in 99.9% a converter will be enough.

I'd ignore that number. Whether a raw converter is enough depends on (1) what you shoot, and (2) how exacting your standards are. I shoot a lot of macro. This produces images that often need relatively little editing because I control lighting, background, etc. As a result, I use pixel editors less than many other people I know. Nonetheless, even with my type of work, the percentage of images that can be handled adequately (by my standards) with only a raw processor doesn't hit 99.9%--even though the raw processor I use has a relatively powerful editing toolbox.

Because you are going to use open-source software with which I am not familiar, I can't give you specific advice. If you were using the software I use (the Adobe suite), I would recommend starting with just the processor because that will allow you to learn a lot about editing--for example, how to use tonal adjustments, sharpening, noise reduction, some local adjustments, etc. Then, once you understand the principles--for example, what the impact of expanding the histogram or imposing an S-curve is--I would gradually start adding the functions of a pixel editor, such as layers and masks.

Dan

[DanK]

George,

You introduce here a lot of noise

That's called in English a gratuitous insult. It has no place here. It's also factually incorrect.

We've discussed this before, but don't forget the difference between Save and Save As/Export

Indeed we have, but it doesn't appear that you understand them, at least as they are implemented in the Adobe suite. In lightroom, there are no save or save as commands; the only way to save an image file of any format is the export command. Until you use the export command, there is no file corresponding to your edits. Photoshop has all three commands; all of them write a new file to disk. In many cases, the results are identical. For example, if you move an image from lightroom to photoshop using the "edit-in" command, the only difference between Save and Save As (assuming you have the relevant parameters set the same) is whether the resulting image is automatically imported into the Lightroom catalog.

One of the reasons this unproductive argument never ends is because you focus only on the fact that an image has to be rendered to be displayed on screen. Even though, to my recollection, not a single person on this forum has ever agreed with you about these arguments, no one has ever disagreed about that fact. It's simply not what the rest of us are discussing.

It's easy enough to see one the effects of the difference between parametric editors and pixel editors. Create a series of fairly extreme edits, including sharpening, contrast adjustment, noise reduction, etc. Then reverse the order of the edits. With a pixel editor, the results will often be noticeably different. For example, this is the reason for the common advice to reduce noise before sharpening--so that you don't sharpen noise. With Lightroom (as I have demonstrated here before), the results are unchanged. Why? Because Lightroom is not creating temporary files as you edit that it uses for producing the final image. The order in which it applies the edits--both in rendering for the screen and for rendering an output file--is independent of the order in which they were entered.

Dan

[Manfred M]

While computer memory is linear as in one-dimensional almost by definition, data structures are not and images are structures of type array, the most common image type being 2D, often - but not necessarily - 3 columns of color data such as RGB by as many rows as are necessary to describe the image. It could be said that the introduction of layers introduces a third array dimension - but that would be stretching it, unless the layers are contiguous with the original image data; otherwise they are simply a collection of 2D arrays within the same file, IMHO. I might be wrong about that and maybe the answer to that is here:

https://en.wikipedia.org/wiki/Array_data_structure

Always good to have a credible reference in discussions like this . . .

I agree Ted and from a technical standpoint, but only useful if the audience understands it. In my case, I was writing to George. Based on his ongoing comments on how editors work, this is not useful in trying to explain this aspect of photography.

On the other hand, we are once again quibbling over details. In my view any view where I need three discrete values to define a point is a 3-dimensional space.

[Manfred M]

A more complex editor doesn't have make better picture, just as a more expensive camera doesn't take better pictures.

This comment is repeated so often I shudder whenever I hear it. It is simply incorrect.

Why do professionals spend money on high-end cameras and lenses if it doesn't take better pictures? Why do all the high end photographers and retouchers do their work with a pixel based editor, usually Photoshop, when there are other less expensive options out there? The very top end photographers do not do their own retouching but will hire an expert retoucher who has the requisite knowledge and experience to turn out a masterful final image.

The answer is simple and anyone who has designed systems knows this. The outcome is limited by the weakest component in the system. In photography, that is often the photographer. This is especially true for beginning or even intermediate level photographers. Once the photographer has reached a certain skill level the other elements can become the limiting factors, whether they be the camera, lens, other equipment or the image processing software (this too has a skill component).

Good photographers know this and invest time (learning how to get the best out of their gear) and effort in acquiring high quality gear to do their work. Isn't it strange that commercial photographers tend to own expensive camera bodies, high quality lenses, sturdy tripods, etc? The same goes for good amateur photographers; they upgrade their gear once they reach the performance limit of their existing equipment to take them to the next level.

The truth is that expensive, high end gear will not give superior results if the photographer does not have the knowledge and skill to get the best out of them. In fact, he or she might get better images out of a camera phone because the automation / AI components in those tools can help overcome the lack of knowledge, skill and experience for that class of photographers.

Similar arguments go for post-processing software. These need knowledge and skill to use them. A basic or intermediate photographer will get the results they want with basic tools. These will generally not suffice for high end photography as the difference between a good image and a great image is usually found in the details of how the post-processing is done. This is where a pixel based editor's strengths come through; they do the details extremely well and when looking at a great image, it's the details that make the difference.

[xpatUSA]

I agree Ted and from a technical standpoint, but only useful if the audience understands it. In my case, I was writing to George. Based on his ongoing comments on how editors work, this is not useful in trying to explain this aspect of photography.

I on the other hand was writing to all readers of this thread which is why my post did not contain a salutation, Manfred. In other words "the audience" is any reader of this thread, not just George.

On the other hand, we are once again quibbling over details.

I was hoping naïvely to avoid such quibbling by not responding directly to your good self, but it appears that that is not to be.

In my view, any view where I need three discrete values to define a point is a 3-dimensional space.

?

[William W]

I am new to post processing and am finding the learning curve a little steep. I am trying to learn rawtherapee since I am now shooting raw on my camera. What other software could I use to help learn post processing. I have GIMP installed on my computer and find that Davies Media Design has extensive tutorials on using GIMP plus I have a large book that I got for Christmas (GIMP 2.8 for Photographers).Not many tutorials on learning rawtherapee. I figure if I can learn basics in GIMP about post processing then it might make it easier to learn RT. Any suggestions would help. Thanks.. . .
I currently do have faststone, but I am using it strictly as a photo organize . . . As far as paid software goes, not an option (not cheap just on a very tight budget).

Hello J B Collins,

Sometimes, one of the teething stages for a new member to a forum group is for them to separate applicable and relevant information from the noise. Often it is useful to research the background and previous comments of those offering advice to assist in the sorting that one needs to do.

You’ve been given fantastic well structured advice that is applicable and relevant to the quite precise outline that you gave in your Opening Post – especially the two facts: that you are new to post processing and that you are on a tight budget.

I have little to add in the way of new material, yet I feel it may be useful to you for me to comment that an exceptional overview has been provided by the tag team of Manfred and Dan, and this has been accented by the “Faststone” commentaries by Ted and John.

Also, I add that I agree totally with George’s comment and Dan’s response to it in Posts #20 & #24, repeated here for your convenience and my bold now for emphasis:


George wrote:

For you [James] it's total irrelevant.

Dan wrote

Exactly right. Not only is this digression irrelevant; it only obscures the answers to your [James’s] question. Manfred and I have given you [James] what I hope is a reasonably clear explanation of how parametric and pixel editors differ and why that matters in practical terms. If anything we wrote is unclear, please ask.

***

Regarding your question about what people here at CiC use for Post Processing – I mainly use Lightroom and Photoshop.

***

I’d like to comment in depth, on this phrase that you used as a qualifier in your Opening Post

since I am now shooting raw on my camera

For me it is important that I capture raw + JPEG (i.e. not exclusively raw).

I think that there are several advantages, generally, for adopting this process.

Here are some (not an exhaustive list) of my reasons and which are connected to the general topic of Post Processing:

> I use the LCD quite often to view the capture(s) that I have made. I use Canon DSLRs; Fuji and Canon Mirrorless. The Camera converts the file to a JPEG so I can view it, usually to look at the exposure “blinkies” and sometimes the Histogram, So I figure why not keep that file anyway – large cards are quite inexpensive nowadays, and unless you are shooting at machine gun rate capture speeds saving raw + JPEG is not a big deal apropos time. (Anyway machine gun rate capture is overrated and un-necessary in many circumstances in which I see it being used – that’s another topic).

> Digital Cameras having “parameters” which the user can set that manipulate the JPEG file, I have one main set of in camera JPEG parameters for each camera, and other three or four for each camera which I only sometimes use. This allows me (if I reasonably nail the exposure) to pull out the JPEG file and pump it through a lightweight Post Processing comprising usually of only a two stage sharpening and then a crop, that’s about 15 seconds, literally, no joking. Most of my images end up displayed on a screen and, with a bit of experience under my belt, mostly all of my screen images are straight from JPEG with minimal editing. I like time spent making of photos, using my cameras, I was never much for spending the time in the darkroom, anyway.

> Occasionally I will make a ripper Photograph, one worth Printing. The more experienced that I have become, the fewer Photographs make the standard of “Suitable for Printing”. Any file worthy of printing – is simple – I have the raw file and that usually means some hours in the (digital) Darkroom: which I deem absolutely necessary to nail a Print to my quality standards.

> It’s not a pressure on me, but the concept of minimal editing, (with the backstop of having the raw file anyway), has allowed me to continue to improve my skills and to not be lazy at the Photographing end of the production cycle and to keep an high level of quality Camera Technique: what I mean is, with the advent of Digital Photography, I think it is very easy to rely on Post Processing as the saviour. The move from Film to Digital has, in general, promoted a culture of reverse thinking that places the Post Processing as the more important element, or at least a get out of gaol free card, to fix up sloppy camera work. Both the Capture Process and the Post Production are very important, but depending upon the USE of the FINAL IMAGE one might reduce the amount of TIME taken in post processing and still have suitable results. On the other hand (and hopefully obviously) the poorer the execution at the Camera end of the production line, the more time usually is required at the Post Production end.

WW