Advice on scanning cover art

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psychoadept 2017-05-05 14:54:48 UTC #1

I needed a new printer and this time I ordered an all-in-one, so I'm about to take the plunge on scanning cover art. I'm just hoping to get a head start on the learning curve.

I've read this page, but I understand that some people prefer to scan at 600dpi?

When it comes to two-page spreads, is there a preference between keeping the pages together or splitting into separate images?

Is there a "best" image format/setting?

I imagine the printer will come with some scanning software, but is there 3rd party software that might be helpful?

Is it possible/worthwhile to create composite images for LPs or posters that are bigger than the scanner?

Any other input is welcome. Thanks!

Failed cover art upload, what now?

aerozol 2017-05-05 20:45:25 UTC #2

I'm not a scanning expert, but I scan using a Pixma MP470 all-in-one (that I don't print on because the ink is total rip), and you can have a look at my scans to see if you like the result/ compare if you want.

I scan at 600dpi in photoshop, crop it in photoshop, and then save as highest quality jpeg with no further post processing.

Exceptions are if it's something tricky like gloss ink or fluro and it doesn't represent what I have in hand, in which case I will use the levels slider and maybe hue/saturation to try get it closer to the product. I also use photoshop to stitch together posters etc bigger than A4.

Two page spreads I always stitch together or leave as is (easier to seperate them later but hard to seamlessly fit together again), for things like the front page of a booklet I'll upload both the spread (front and back in one) and the front separately - it doesn't hurt.

I haven't tackled LPs but I've thought about it... the stitching and scanning will be a big time investment. I'm only tempted for LP's that have no cover image of any quality online at all. Let me know how it goes
Alternatively, maybe your library has an A3 scanner? Probably worth the time to check.

My scans (except for LPs!): https://beta.musicbrainz.org/collection/ac668219-3f0e-4f11-98a9-6d400e6479a2

rdswift 2017-05-05 23:01:45 UTC #3

I usually scan at 600dpi and then resize the image back to 1000 x 1000 px (for covers) before posting. That allows me to do any necessary touching up at the higher resolution before the resizing. It seems that everybody has their own way of doing it. My advice is to find out what works for you with the hardware and software you use, and gives you the kind of quality you're comfortable sharing with the world.

I've done them both ways, but am moving more toward keeping the pages together. I figure if someone wants separate images, it's easier for them to extract them out of the combined image than it would be for someone to stitch individual images together. Besides, it's (slightly) less work for me that way, and I'm basically lazy.

Under Windows I use a free program called Paint.net (https://www.getpaint.net/index.html) to handle all the scanning, touch up and resizing. I find it powerful enough for my needs and pretty easy to use. And the price was right. Your mileage may vary.

I've done this a couple of times by scanning partial images and then stitching them together (in Paint.net) to get a single composite image. One that comes to mind is the booklet for Prairie Noise - Play This Disc. I can't remember if it was 4 or 6 scanned images that I stitched together, but the final image is here.

There's a fair bit of work required to get a decent result, so I don't do it very often. Did I mention that I'm basically lazy?

One of these days, I'm actually planning to try using my digital camera and (soft) portrait lighting to try capturing the oversize images that way. Not sure if it will yield the desired quality, but it's worth a shot because it will be a LOT easier than scanning and stitching. If it's even close to a good result, I may try using a non-glare sheet of glass (or plexiglass) to press the poster flat for the shot.

WovenTales 2017-05-06 03:18:18 UTC #4

I actually scan in 1200 dpi, touch up the image, and then scale it down to 600 before uploading, but I'll be the first to admit that's kind of ridiculous. I would personally recommend GIMP for post-processing -- use the heal tool to get rid of the dust and such (and, if you can track it down, the "Heal selection" plugin for larger stains), and I've found that the secret to good colors is to go into "Colors -> Levels" and pick black and white points from the image (though you can definitely keep playing around with them after that to keep tweaking how it looks).

About using a handheld camera, I've had surprising luck in using the perspective transform to fix images from ebay if I add 8-tracks. The quality is still probably below what you'd get from scans, but with enough care put into taking the picture, you might be able to get it not too far behind.

mfmeulenbelt 2017-05-06 06:30:58 UTC #5

Have you read this page too?

When it comes to two-page spreads, is there a preference between keeping the pages together or splitting into separate images?

I prefer to upload the pages separately, unless two pages make up one image of course. It is a little bit more work to split those pages, so it depends on the time I have.

Is it possible/worthwhile to create composite images for LPs or posters that are bigger than the scanner?

It is possible and worthwhile, but if it is a large poster and you are scanning at high DPI, you might run out of RAM when you are stitching them together. I have 6GB of RAM and and A3 poster at 600dpi just works, but anything bigger than that is problematic.

mmirG 2017-05-06 12:38:52 UTC #6

Someone, somewhere, convinced me that png was a better way to go. What's the views of the more experienced scanners about png vs jpg?

mfmeulenbelt 2017-05-06 14:48:13 UTC #7

Short answer: jpeg is shit, use png.

Long answer: jpeg is an ancient lossy format which creates a lot of ugly artefacts every time the image is saved again, even at the highest quality settings. Png is getting pretty old too, but it is lossless, which means that saving images again and again doesn’t degrade the image quality. Jpeg is a bit smaller than png, but storage is a cheap as dirt nowadays, and the Internet Archive has never complained about images in the Cover Art Archive being too big.

rdswift 2017-05-06 16:01:49 UTC #8

Thanks for this. I haven't used Gimp in ages, and then only under Linux. Very powerful program. I didn't even realize that there was a Windows version. I'm downloading it now and will give it a try.

rdswift 2017-05-06 19:45:36 UTC #9

@psychoadept, forget what I said earlier about using Paint.net for the scanning and editing. After taking @WovenTales suggestion about trying Gimp, I'm sold. It has all the same features as Paint.net (including the ability to acquire an image directly from the scanner) plus a few more if you install the scripts and plugins.

The "heal selection" thing is amazing. If you want to install that function, I suggest getting the files from here because there is another version floating around that doesn't work properly (and of course that's the one I found and installed first). There is a text file in the zip file that explains how to install it (where to copy the files).

rdswift 2017-05-06 20:56:01 UTC #10

I also found a plug-in for Gimp that significantly helps the process of stitching together files to recreate those posters and such. It is called Stitch Panorama and can be found here. It is pretty old but still works with the latest version of Gimp.

It seems to work pretty well, but you really need to follow the instructions and pay attention to which files you select as the reference image and the transformed image. For example, if you're trying to stitch in a corner to an image that has everything except that corner, you need to set the corner image as the reference. That seems a bit counter-intuitive to me, but it definitely makes a difference.

With this tool, I may even start scanning and stitching together posters again.

psychoadept 2017-05-06 22:18:00 UTC #11

Thanks, everybody!

I already use gimp, so that's great to know. I'll definitely look up those plugins!

My instinct was to go with png so I'll stick with that unless someone has a good argument for a different format.

My inclination is to do separate images for separate pages. Since most album art displays are designed for cover art which is roughly square, it will make viewing them easier.

As for stitching, I might try it, later. Or maybe I'll just take my LPs and hang out at the office after hours...

rdswift 2017-05-06 23:45:25 UTC #12

The "after hours" thing is likely a good way to go if you have that option. Unfortunately, I don't.

I also wanted to let you guys know that I found another stitching utility that seems to work even better than Stitch Panorama. It is a stand-alone utility called Hugin. It is primarily designed to build a panorama from digital photos, taking into account lens types and settings, but there is a tutorial on how it can also be used to stitch scanned image files. It does a very good job and it's also very fast.

Anyway, just another option.

aerozol 2017-05-07 00:29:08 UTC #13

Thanks for this, I've always used jpg out of habit but I think it's time to make the leap to png.

mfmeulenbelt 2017-05-07 06:22:42 UTC #14

Thank you for letting us know about both. I always used to do this by hand in the GIMP, and that’s a lot of work, and I have to do colour balance myself.

ZincRider 2017-05-08 09:16:47 UTC #15

Yes, 600dpi should be enough to capture the print screen accurately. Lower resolution may cause moire patterns, higher is hardly an improvement.

If you don't want to bother with descreening your images (which can be a pain if you want to do it properly) it's probably a good idea not to scale them down. If you must, make sure to use a resampling algorithm that doesn't bring out the moire so much.

Hugin is great. I use it to stitch partial scans of 12'' record sleeves.

I wouldn't recommend picking black and white points. It will usually clip shadows and highlights. Picking a neutral point if necessary works a lot better for me.

If you really want to get accurate colors you could get a software like Silverfast to create a calibrated color profile for your scanner, but it sure ain't no budget solution..

Freso 2017-05-08 18:37:20 UTC #16

I usually just scan in 1200 DPI to PNG and (after maybe doing a slight bit of cropping) upload that. If people want more polished cover art images, I have posted my source material and others are free to download and edit/modify/re-upload. (And @rdswift says he's lazy? Psh. )

Note that CAA will "soon" have a new max-dimension=1200px download option (right now the biggest that isn't "original size" is max-dimension=500px):
https://tickets.metabrainz.org/browse/CAA-88
- so your 1000×1000 images will actually be smaller than this.

Also, do you square cover art even for non-square covers (e.g., digipaks)? (I hope not!)

rdswift 2017-05-08 19:13:30 UTC #17

Then it's probably a good thing that I just this morning decided to change to 1500 x 1500. Actually, with the way things are changing, I think I may change that to 2000 x 2000 px.

I do, but I also upload scans of the full digipak covers so it's all there for the archive. My reason is that, unless you specify in Picard to use the original image size rather than 500 x 500 px (for example), MB / CAA / Picard will take the largest dimension of the file and resize it to the specified size, and then fill in the smaller dimension with a blank background to create a square image. I would rather have a nicely cropped square image than one with blank filler bars on the top and bottom.

On those rare occasions when you just can't crop an image enough to make it square, I will create my own square image with an appropriate color / background used for the filler bars. I don't upload these, but just use them for tagging my own collection.

Uploading squared images to CAA

WovenTales 2017-05-08 19:25:25 UTC #18

I'll try the neutral point next time I'm working on cover art, but I'm not talking about taking some random point as black. My scanner shows them both as somewhat grey, and all I''m doing is restoring the parts of the image that should be completely black or completely white. Maybe I could have said that more clearly before, but I'm not particularly worried about clipping highlights/shadows by choosing what are already the brightest/darkest parts of the image.

kepstin 2017-05-08 19:31:28 UTC #19

Hi,

I've got a little page up with some recommendations on scanners for album art scanning, see https://www.kepstin.ca/blog/recommended-scanners-for-album-art-scanning/ - it mentions the two different types of sensors used, and the tradeoffs of picking one over the other.

For the images that I upload to CAA:

I normally scan at 1200 dpi. Any temporary files must use a lossless format, e.g. png, tiff (usually), psd, xcf.
You'll almost always have to use the 'levels' controls to adjust the black and white points, as they depend on the paper and ink used. If possible, save the settings as a preset so you can use the same levels on all pages of the booklet so they match. I don't use the color picker, but just drag the "all channels" black/white point markers to get the brightness correct.
I process the images using blur, smoothing, sharpening, etc. filters - I make heavy use of the G'MIC filters in GIMP - and in the process downscale to 300dpi (¼ the original height/width - this makes CD covers around 1400-1500px depending on crop). Normal screen-printed images don't have enough detail to make sizes >300dpi useful (although text can be sharper at higher resolution.)
I then save as high quality JPEG (~95%), and upload that to CAA. Since the final image has the screening pattern removed, JPEG doesn't introduce noticeable quality loss here. (I'm probably gonna start doing PNG instead for future scans.)

Freso 2017-05-11 12:05:17 UTC #20

8 posts were split to a new topic: Uploading squared images to CAA