§ 1236.50 - Requirements for digitizing permanent paper and photographic print records.

§ 1236.50 Requirements for digitizing permanent paper and photographic print records.

(a) Overview. This section describes the minimum requirements appropriate for digitizing paper records. Depending on the physical characteristics of the source records, the agency must select the applicable specifications described in either table 1 to paragraph (d) of this section for modern textual paper records or the table 2 to paragraph (e) of this section for photographic prints and paper records with fine details. Agencies must implement appropriate equipment, lighting, special handling, or imaging methods to ensure the capture of all information. Agencies may exceed these requirements, if necessary, to capture fine detail or to meet their own business needs.

(b) Image quality parameters. The performance parameters are based on FADGI three-star aim points and tolerance ranges.

(c) Equipment requirements. The equipment used to digitize Federal records must be appropriate for the media type, and capable of achieving documented project objectives without damaging the source records.

(d) Requirements for digitizing modern textual paper records. For these records, produce image files at a minimum of 300 ppi sized to the source document.

(1) Records suitable for the specifications in table 1 to this paragraph (d) for modern textual paper records are modern textual documents with a well-defined printed type (such as typeset, typed, laser-printed), and with moderate to high contrast between the ink of the text and the paper background. Performance metric values in table 1 for modern textual paper records conform to the FADGI “Documents (Unbound): Modern Textual Records” category, and are appropriate when source records do not have visible content with L* values darker than 20. Neutral reference patches on the evaluation test target with L* less than 20 are not used for analysis.

(2) For other paper records such as manuscripts, illustrations, graphics, and documents with poor legibility or diffuse characters (such as carbon copies or Thermofax) that have visible content with L* values darker than 20, agencies must evaluate neutral reference patches on the evaluation test target with L* greater than 20. (These values equate to FADGI three-star for “Documents (Unbound): General Collections”).

(3) The agency must digitize in an acceptable RGB color mode if records contain color or other characteristics that are necessary to interpret the information of the source record, or that would be lost when digitizing using grayscale gamma 2.2.

(4) At a minimum, the agency must digitize the paper records covered by this paragraph to the following parameters:

Table 1 to Paragraph (d)—Requirements for Digitizing Permanent, Modern Textual Paper Records Table

Digital file specifications	Attributes
Color mode	color or grayscale.
Bit depth	8 or 16.
Color space	gray gamma 2.2, AdobeRGB1998, sRGB, ProPhoto RGB, ECIRGBv2.
Resolution (Sampling Frequency) (Units are Pixels Per Inch/ppi minus Reproduction Scale Accuracy)	≥294 ppi (300 ppi—2%).
Measurement parameters	Performance metric values Difference from aim (applies to 20 ≤ L* ≤ 100).
Tone Response (OECF) L* (Units Colorimetric ΔL*) gray patches that meet the measurement parameters	± 5.
White Balance (Units Colorimetric ΔE(a*b*)) gray patches that meet the measurement parameters	≤4%.
Lightness Uniformity (Units Colorimetric—Standard Deviation Divided by Mean L*)	≤3%.
Average Color Accuracy (Units Colorimetric—Mean ΔE 2000—for patches meeting the measurement parameters)	≤ 3.5.
Color Accuracy 90th Percentile (Units Colorimetric—2.5 times average deviation for patches meeting the measurement parameters)	≤ 8.75.
Color Channel Misregistration (Units Pixels)	< 0.5 pixel.
SFR 10 (Sampling Efficiency) (Measurement is a Ratio %)	>80%.
MTF50 (50% SFR) (Percentage of Half Sampling Frequency) [Lower, Upper]	Percentage of half sampling frequency: [>40%, <75%].
Reproduction Scale Accuracy (Units % Difference from Header PPI)	<±2%.
Sharpening (Units Max Modulation)	< 1.1.
Noise (Upper Limit) (Units Std Dev of L*)	≤ 2.
Noise (Warning Limit) (Units Std Dev of L*)	≥.25.

(e) Requirements for digitizing photographic prints and paper records that have fine details. Records that have fine detail, require a high degree of color accuracy, or have other unique characteristics, must be captured using the specifications in table 2 to this paragraph (e) for photographic prints and paper records with fine details. For these records, produce image files (as described table 2) at a minimum of 400 ppi sized to the source document (these performance values equate to FADGI three-star category “Prints and Photographs”). It may be necessary to apply a higher resolution than the minimum for some records that have fine detail.

(1) These specifications apply to records such as photographic prints, graphic-arts prints (for example, lithographs or intaglio), drawings, embossed seals, and records that have information that cannot be captured by the parameters in table 1 to paragraph (d) of this section for modern textual paper records.

(i) For records in which the smallest significant detail is 1.0 mm or smaller, such as aerial photographs and topographic maps (which require a high degree of enlargement and precision to ensure the dimensional accuracy of the scans), the agency must increase the resolution to capture all the information in the source record.

(ii) For many imaging devices, increasing the ppi settings may not increase the actual resolution level or capture the desired detail. The equipment for digitizing records with fine detail must be capable of meeting the higher quality parameters. It may be necessary to exceed the parameters in table 2 to this paragraph (e) to capture all the information inherent in the records.

(2) The agency must digitize photographic prints, including monochrome and black and white, using a color mode.

(3) The agency must digitize in an acceptable color mode if records contain color or other characteristics that are necessary to interpret the information of the source record, or that would be lost when digitizing using grayscale gamma 2.2.

(4) At a minimum, agencies must digitize all records covered by this paragraph to the following parameters:

Table 2 to Paragraph (e)—Requirements for Digitizing Permanent, Photographic Print Records and Paper Records That Have Fine Details

Digital file specifications	Attributes
Color mode	color or grayscale.
Bit depth	8 or 16.
Color space	Gray gamma 2.2, AdobeRGB1998, ProPhoto RGB, ECIRGBv2.
Resolution (Sampling Frequency) (Units are Pixels Per Inch/ppi minus Reproduction Scale Accuracy)	≥392 ppi (400 ppi—2%).
Measurement parameters	Performance metric values
Tone Response (OECF) L* (Units Colorimetric ΔL2000*) for any given gray patch	± 4.
White Balance (Units Colorimetric ΔE(a*b*)) for any given gray patch	≤4.
Lightness Uniformity (Units Colorimetric − Standard Deviation Divided by Mean)	<3%.
Average Color Accuracy(Units Colorimetric—Mean ΔE 2000—average deviation of all patches)	<3.5.
Color Accuracy 90th Percentile (Units Colorimetric—2.5 times average deviation of all patches)	<8.75.
Color Channel Misregistration (Units Pixels)	<0.5 pixel.
SFR10 (Sampling Efficiency) (Measurement is a Ratio %)	80%.
SFR50 (50% SFR) (Units Percentage of Half Sampling Frequency) [Lower, Upper]	Percentage of half sampling frequency: [>40%, <75%].
Reproduction Scale Accuracy (Units % Difference from Header PPI)	<± 2%.
Sharpening (Units Max Modulation)	<1.1.
Noise (Upper Limit) (Units Std Dev of L*)	<2.
Noise (Lower Limit) (Units Std Dev of L*)—A warning should be raised if the image doesn't meet this criteria	≥.25.