Difference between revisions of "Guides/Scanning Cover Art"

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The size of the scanner is important to consider if you want to capture record covers in one pass. If you want to scan LP covers, a 12″×17″ scanner will work better than an 11.69″×17″ scanner but still usually leaves off part of an edge (LP covers are 12.375″ squares), a camera setup can be used to photograph the LP cover.
 
The size of the scanner is important to consider if you want to capture record covers in one pass. If you want to scan LP covers, a 12″×17″ scanner will work better than an 11.69″×17″ scanner but still usually leaves off part of an edge (LP covers are 12.375″ squares), a camera setup can be used to photograph the LP cover.
   
[[File:sttu68.png|alt=Dimensions of standard paper sizes and scanners. Numbers in bold are exact, and numbers not bolded are rounded. *Scanner pixel density is typically measured in pixels per inch, which makes it difficult to comply with a millimeter standard.5.|thumb|left|712x712px|Dimensions of standard paper sizes and scanners. Numbers in bold are exact, non-bold numbers are rounded.''*Scanner pixel density is typically measured in pixels per inch (PPI), please prefer to select scanner models by PPI.'']]
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[[File:sttu68.png|alt=Dimensions of standard paper sizes and scanners. Numbers in bold are exact, and numbers not bolded are rounded. *Scanner pixel density is typically measured in pixels per inch, which makes it difficult to comply with a millimeter standard.5.|thumb|712x712px|Dimensions of standard paper sizes and scanners. Numbers in bold are exact, non-bold numbers are rounded.''*Scanner pixel density is typically measured in pixels per inch (PPI), please prefer to select scanner models by PPI.'']]
 
 
 
 
 
 
 
 
 
 
   
 
===== Sensor Type =====
 
===== Sensor Type =====

Revision as of 06:05, 26 September 2022

How to Make High Quality Scans of Music Artwork

Version MB-0.1.1-20220518

Layout

This guide is divided into two parts: one on scanning and one on digitally processing scans. The first part is mostly complete, but the digital processing part needs refining with current techniques from the community. It should still be helpful in its current form to anyone wanting to scan CD and vinyl artwork for inclusion in MusicBrainz' Cover Art sections.

Overview

Digitizing artwork can be simple and easy, but it can also be slow and tedious if you plan to remove as many imperfections as possible. This guide explains in detail how you get the best quality scans without spending too much time with diminishing returns. It’s unreasonable to expect everyone to spend hours removing every speck of dust or share gigantic files, so automation is used where possible and lossy compression where it makes sense. I hope you can use this guide as a reference whether you are scanning record covers, CD fronts, booklets, or discs.

The basic workflow for scanning is to:

  • Scan
  • Rotate
  • Deskew
  • Crop
  • Straighten text
  • Color correct
  • Descreen
  • Clean up
  • Create JPG

Not necessarily in that exact order. You may not need to do all these steps, or you may need to do more.


Notes on this guide:

  1. With respect to your time, we try to condense as much relevant information as possible into step-by-step sections without being too wordy. Currently, there are several sections that could use step-by-step guides that don’t have them, but more are planned with instructions in the future.
  2. This guide is not limited to free software since we try to recommend the best possible tools, free or not.
  3. Focus on Windows compatible software, but Mac and Linux alternatives are mentioned where appropriate.

A step-by-step approach is used in lieu of oversimplification to avoid confusion for beginners. Discussion and feedback thread available here:

Part One: Digitizing

Converting a cover to a digital image is best done with a flatbed scanner (preferred) or a camera setup. Paper-fed scanners should be avoided.

Scanners

Size

The size of the scanner is important to consider if you want to capture record covers in one pass. If you want to scan LP covers, a 12″×17″ scanner will work better than an 11.69″×17″ scanner but still usually leaves off part of an edge (LP covers are 12.375″ squares), a camera setup can be used to photograph the LP cover.

Dimensions of standard paper sizes and scanners. Numbers in bold are exact, and numbers not bolded are rounded. *Scanner pixel density is typically measured in pixels per inch, which makes it difficult to comply with a millimeter standard.5.
Dimensions of standard paper sizes and scanners. Numbers in bold are exact, non-bold numbers are rounded.*Scanner pixel density is typically measured in pixels per inch (PPI), please prefer to select scanner models by PPI.
Sensor Type

For best results, get a Charged-Coupled Device (CCD) scanner as opposed to a Contact Image Sensor (CIS) device. CCDs tend to capture better quality scans and have a much greater depth of field. CIS scanners blur anything that is not pushed right up to the screen, which would be a problem when scanning spines of booklets or anything not completely flat (example).

This is not to say CCD scanners always look better than CIS. For example, the CIS scanner, Canon PIXMA MG3220, creates raw scans with more vibrant and accurate colors than the more expensive CCD, Plustek OpticPro A320L. To get comparable color quality, the colors of the CCD’s raw scan need to be adjusted based on the scanner’s calibration, then the brightness levels adjusted. After this the CCD scan is superior since everything is in focus and has more detail for the intended resolution.

Resolution

The scanner should have a maximum real resolution of at least 1200 dpi. An advertised “maximum” resolution that is larger than the sensor optical rating is the interpolated resolution done in software, which will not be used in most cases.

If a scanner’s specifications state two DPIs, such as 1200x2400 dpi, then the smaller number is the resolution of the scanning sensor and the larger is the precision of the stepper motor moving the sensor. If you choose to scan at a resolution that is not a factor of the stepper motor dpi then some location error will occur, but not much.¹ Your scanner might avoid this error if it scans at the next highest compatible stepping size and reduces the image dimensions in software.