On binning images

[Steven Ruttenberg]

So as not to detract from the other thread, I will move here. Assuming I did the math right here are my thoughts. It would all depend on the quality of the binned image which I am going to experiment with over the weekend to see how this plays out. Here are my thoughts.

So, currently I get a 1.8gb size 4x5 negative at 4200ppi and the files look great. I was reading on binning pixels from the Vuescan website and if I did a 3x3 binning, I would end up with a much smaller file, something like 39,200,000 vs 352,800,000 pixels.

This equates to and image that is 7000 x 5600 (equivalent to 1400ppi scan) vs 21,000 x 16,800 (equivalent to 4200ppi scan) pixels. While this is supposed to be better than scanning at 1400ppi and supposedly will reduce noise, would it still allow me a solid 16x20 or 32x40 print at 300ppi. 7000/300 is 23 x 18, so yes there, but 32 x40 would be 175ppi for printing instead of 300ppi. Or would you still be able to get a quality 32 x40 from the binned data which would require some interpolation to get to 300dpi? Or would 175ppi suffice (I don't think it would)

Definitely scanning at 1400ppi is a non-starter for sure. Yes, I can resize and do in photoshop starting with the original scanned image which is at 4200ppi.

Then there is 2x2 binning which still would not get you to 32 x40. That requires to reduce the scan dpi to 2400ppi which I have found to not be as good as it is cracked up to be. So looks like I will stay with 4200.

Another option is scan at max of 6400ppi then do a 2x2 binning which would provide for an easy 32 x 40 image which would be the same as scanning at 3200ppi, but supposedly better than scanning at 3200ppi. This would also allow the file to a fair amount smaller at 204,800,000 saving memory needed for the 48 million less pixels than scanning at and saving at 4200ppi.

All that to ask, have you tried binning? Other than noise reduction if any, how much quality do you lose? I am going to try this next scan after I zero in the focus on my V850 (got my resolution target and my transmission step and reflectance step references)

ps,
if anyone takes interest in this thread, lets not get into shouting matches and puffing our chests out over which is better drum or flatbed. I just found this topic quite interesting with possible potential as I scan at high resolutions which are huge files. The process of binning is the same regardless of scanner type as it is all the same or similar algorithm for averaging a group of pixels (data points for those who do testing and such). I am sure will all understand 2x2 is averaging over 4 pixels while 3x3 is averaging over 9 pixels.

Anyway, if interest is shown, let's keep it civil and fun!

[Pere Casals]

With the target you should see around 60 to 45 lp/mm depending on axis, last elements of Group 5. Let's see what you find by adjusting focus perfectly...

You can also test USM in Ps with high zoom in PS until you detect overshot.

I'd suggest you paste a crop of the target in a scanned image to be edited (at same dpi), so you would be able to track the quality degradation of the full image after resizing, binning, etc by inspecting what happened in the pasted crop.

[Steven Ruttenberg]

Interesting article on binning. I am reading now.

https://asp-eurasipjournals.springer...-6180-2012-125

[Steven Ruttenberg]

Steven, just a comment about units, when speaking about printers we should use ppi, not dpi, because each particular printer may use several dots to build a pixel. With scanners dots per inch and pixels per inch are the same, but not with printers.

With the target you should see around 60 to 45 lp/mm depending on axis, last elements of Group 5. Let's see what you find by adjusting focus perfectly...

You can also test USM in Ps with high zoom in PS until you detect overshot.

I'd suggest you paste a crop of the target in a scanned image to be edited (at same dpi), so you would be able to track the quality degradation of the full image after resizing, binning, etc by inspecting what happened in the pasted crop.

I edited for pixels per inch.

[Steven Ruttenberg]

In photoshop everything is in ppi, where as the printers are in dpi. I always found that a bit disconcerting. I want 300ppi, but the printer say can go to 2400dpi. Looking at this, this is my ipf6400 resolution max 2400x1200dpi. This then tells me I have 8 times the number of drops per inch than I do image pixels. So the question is, what the printer is doing with the information? Cause at 1 ppi to 8dpi for 300ppi image resolution does this become the minimum number? One could use say 150ppi and stay with printer max of 2400x1200 which would give 16 drops for every pixel. If my viewing distance is 25 feet, I can certainly get a way with less ppi and even dpi, but the closer the viewing distance the higher the ppi needs to be and the dpi.

Now, throw in binning.

[Pere Casals]

I want 300ppi, but the printer say can go to 2400dpi.

It depends on the printer, in a Lambda/Frontier/Lightjet there is a single dot per pixel, as dots are continous RGB tone, a dot can have any density (BW photopaper) and also any hue (C photopaper). Inkjets usually need to print several dots of different colors in a pixel to deliver an equivalent result, even if it's BW because a single droplet per pixel cannot make an smooth grayscale. If an inkjet uses several BW inks of different opacity then aparent resolving power can be enhanced.

[Peter De Smidt]

The printer uses many dots, including usually of different colors, to make up one pixel from the input file. All that matters from a file perspective is what's the best input value for the printer. With Epsons, that's 720ppi, and with Canon's it's 600ppi. Of course you can use less. The results will depend on the file quality, image content, printing medium (glossy, matte, canvas, hot press, cold press....).

[Jac@stafford.net]

Enlighten me, please. How exactly does binning apply to storing digital images, and to what end for printing? For most cases resolution and accutance is diminished. Rationale - perhaps to streamline ordinary consumer prints which are small, and consumer exceptions are low.

Aside Topic to all: Is your printer smarter than you are?

[Ted Baker]

All that to ask, have you tried binning?

I never use binning, other than what the scanner does by design when you select a lower resolution. Which is probably just a variation on simple nearest neigbour binning.

I scan at the highest resolution that I have patience for. This is currently 2400 on my 4990. If it was faster I would always use 4800. But I don't have the patience.

Even though the resolution of the 4990 at 50% contrast is something like 1500dpi.

That way I can choose the re sampling algorithm, which for me is Lanczos. This gives a slightly better result than simple nearest neighbour or binning you describe. So since its an easy choice I choose that one.

The way I look at is you can't change the sample size of the sensor. But you can potentially change many of the processing steps from scan to print, so it makes sense to choose the best option as you move along.

Admittedly the differences are very minor, so scan time is the dominant factor for me.

[Steven Ruttenberg]

Currently I scan at 4200ppi. I t by en size image to dimension I want at 300ppl and then print at Canons highest resolution of 600dpi which Canon has two settings for, stand and highest quality. I use highest quality and get good images. I think I tried 600ppi at dimensions I wanted and I was warned by PS the t was way to high.

I was curious about binning if technology had caught up to us. Ie, scan at highest resolution then store in a format that saves space but with little to no degradation. Noise reduction seems to be only plus still.