Non-photo blue

Last updated
Non-Photo Blue
 
Gtk-dialog-info.svg    Colour coordinates
Hex triplet #A4DDED
sRGB B (r, g, b)(164, 221, 237)
HSV (h, s, v)(193°, 31%, 93%)
CIELChuv (L, C, h)(85, 34, 214°)
Source[Unsourced]
ISCC–NBS descriptor Very light greenish blue
B: Normalized to [0–255] (byte)
(1) Colour copy of non-photo blue pencil. (2) Colour copy of blue pen. (3) Grayscale copy of non-photo blue pencil. (4) Grayscale copy of blue pen. NonPhotoBluevs.BluePen.jpg
(1) Colour copy of non-photo blue pencil. (2) Colour copy of blue pen. (3) Grayscale copy of non-photo blue pencil. (4) Grayscale copy of blue pen.

Non-photo blue (or non-repro blue) is a common tool in the graphic design and print industry, [1] [2] being a particular shade of blue that cannot be detected by graphic arts camera film. This allows layout editors to write notes to the printer on the print flat (the image that is to be photographed and sent to print) which will not show in the final form. It also allows artists to lay down sketch lines without the need to erase after inking.

Contents

Change in function

More recently, with digital scanning and image manipulation, non-photo blue fulfills its function in a different way. The artist can do their sketch and inking in the traditional manner and scan the page. Most scanners will detect the light blue lines. However, shifting to greyscale and increasing the contrast and brightness of the scanned image causes the blue to disappear. Another common approach involves replacing the blue channel with another channel – typically the red channel. The exact processes may differ depending on the scanner, settings and image-editing software, but the concept remains the same.

Black ink

The difference between the non-photo blue and black ink is great enough that digital image manipulation can separate the two easily. If a black-and-white bitmap setting is scanned in, the exposure or threshold number can be set high enough to detect the black ink or dark images being scanned, but low enough to leave out the non-photo blue. On a threshold scale of 0–255, this number would be approximately 140. Only with a considerably low threshold setting will the blue be detected; this however may greatly distort black lines and add a lot of noise and black speckles, making the image potentially almost unrecognizable. Scanning in black-and-white makes it possible for the non-photo blue still to serve its original purpose, as notes and rough sketching lines can be placed throughout the image being scanned and remain undetected by the scan head.

See also

Related Research Articles

<span class="mw-page-title-main">Raster graphics</span> Matrix-based data structure

In computer graphics and digital photography, a raster graphic represents a two-dimensional picture as a rectangular matrix or grid of pixels, viewable via a computer display, paper, or other display medium. A raster is technically characterized by the width and height of the image in pixels and by the number of bits per pixel. Raster images are stored in image files with varying dissemination, production, generation, and acquisition formats.

<span class="mw-page-title-main">RGB color model</span> Color model based on red, green, and blue

The RGB color model is an additive color model in which the red, green and blue primary colors of light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additive primary colors, red, green, and blue.

<span class="mw-page-title-main">Optical character recognition</span> Computer recognition of visual text

Optical character recognition or optical character reader (OCR) is the electronic or mechanical conversion of images of typed, handwritten or printed text into machine-encoded text, whether from a scanned document, a photo of a document, a scene photo or from subtitle text superimposed on an image.

<span class="mw-page-title-main">Inkjet printing</span> Type of computer printing

Inkjet printing is a type of computer printing that recreates a digital image by propelling droplets of ink onto paper and plastic substrates. Inkjet printers were the most commonly used type of printer in 2008, and range from small inexpensive consumer models to expensive professional machines. By 2019, laser printers outsold inkjet printers by nearly a 2:1 ratio, 9.6% vs 5.1% of all computer peripherals.

<span class="mw-page-title-main">Halftone</span> Printing process

Halftone is the reprographic technique that simulates continuous-tone imagery through the use of dots, varying either in size or in spacing, thus generating a gradient-like effect. "Halftone" can also be used to refer specifically to the image that is produced by this process.

<span class="mw-page-title-main">Dots per inch</span> Measure of dot density

Dots per inch is a measure of spatial printing, video or image scanner dot density, in particular the number of individual dots that can be placed in a line within the span of 1 inch (2.54 cm). Similarly, dots per centimetre refers to the number of individual dots that can be placed within a line of 1 centimetre (0.394 in).

<span class="mw-page-title-main">Image scanner</span> Device that optically scans images, printed text

An image scanner—often abbreviated to just scanner—is a device that optically scans images, printed text, handwriting or an object and converts it to a digital image. Commonly used in offices are variations of the desktop flatbed scanner where the document is placed on a glass window for scanning. Hand-held scanners, where the device is moved by hand, have evolved from text scanning "wands" to 3D scanners used for industrial design, reverse engineering, test and measurement, orthotics, gaming and other applications. Mechanically driven scanners that move the document are typically used for large-format documents, where a flatbed design would be impractical.

Optical mark recognition (OMR) collects data from people by identifying markings on a paper. OMR enables the hourly processing of hundreds or even thousands of documents. For instance, students may remember completing quizzes or surveys that required them to use a pencil to fill in bubbles on paper. A teacher or teacher's aide would fill out the form, then feed the cards into a system that grades or collects data from them.

A penciller is an artist who works on the creation of comic books, graphic novels, and similar visual art forms, with a focus on the initial pencil illustrations, usually in collaboration with other artists, who provide inks, colors and lettering in the book, under the supervision of an editor.

Color printing or colour printing is the reproduction of an image or text in color.

Film-out is the process in the computer graphics, video production and filmmaking disciplines of transferring images or animation from videotape or digital files to a traditional film print. Film-out is a broad term that encompasses the conversion of frame rates, color correction, as well as the actual printing, also called scannior recording.

<span class="mw-page-title-main">Film scanner</span> Device for scanning photographic film

A film scanner is a device made for scanning photographic film directly into a computer without the use of any intermediate printmaking. It provides several benefits over using a flatbed scanner to scan in a print of any size: the photographer has direct control over cropping and aspect ratio from the original, unmolested image on film; and many film scanners have special software or hardware that removes scratches and film grain and improves color reproduction from film.

<span class="mw-page-title-main">3D scanning</span> Scanning of an object or environment to collect data on its shape

3D scanning is the process of analyzing a real-world object or environment to collect three dimensional data of its shape and possibly its appearance. The collected data can then be used to construct digital 3D models.

In computer graphics, image tracing, raster-to-vector conversion or raster vectorization is the conversion of raster graphics into vector graphics.

A camera raw image file contains unprocessed or minimally processed data from the image sensor of either a digital camera, a motion picture film scanner, or other image scanner. Raw files are so named because they are not yet processed, and contain large amounts of potentially redundant data. Normally, the image is processed by a raw converter, in a wide-gamut internal color space where precise adjustments can be made before conversion to a viewable file format such as JPEG or PNG for storage, printing, or further manipulation. There are dozens of raw formats in use by different manufacturers of digital image capture equipment.

<span class="mw-page-title-main">Flying-spot scanner</span>

A flying-spot scanner (FSS) uses a scanning source of a spot of light, such as a high-resolution, high-light-output, low-persistence cathode ray tube (CRT), to scan an image. Usually the image to be scanned is on photographic film, such as motion picture film, or a slide or photographic plate. The output of the scanner is usually a television signal.

The aim of color calibration is to measure and/or adjust the color response of a device to a known state. In International Color Consortium (ICC) terms, this is the basis for an additional color characterization of the device and later profiling. In non-ICC workflows, calibration sometimes refers to establishing a known relationship to a standard color space in one go. The device that is to be calibrated is sometimes known as a calibration source; the color space that serves as a standard is sometimes known as a calibration target. Color calibration is a requirement for all devices taking an active part in a color-managed workflow and is used by many industries, such as television production, gaming, photography, engineering, chemistry, medicine, and more.

<span class="mw-page-title-main">Scanography</span> Graphic arts medium

Scanography, more commonly referred to as scanner photography, is the process of capturing digitized images of objects for the purpose of creating printable art using a flatbed "photo" scanner with a CCD array capturing device. Fine art scanography differs from traditional document scanning by using atypical objects, often three-dimensional, as well as from photography, due to the nature of the scanner's operation.

<span class="mw-page-title-main">Book scanning</span> Process of converting physical media into digital media

Book scanning or book digitization is the process of converting physical books and magazines into digital media such as images, electronic text, or electronic books (e-books) by using an image scanner. Large scale book scanning projects have made many books available online.

<span class="mw-page-title-main">Image editing</span> Processes of altering images

Image editing encompasses the processes of altering images, whether they are digital photographs, traditional photo-chemical photographs, or illustrations. Traditional analog image editing is known as photo retouching, using tools such as an airbrush to modify photographs or editing illustrations with any traditional art medium. Graphic software programs, which can be broadly grouped into vector graphics editors, raster graphics editors, and 3D modelers, are the primary tools with which a user may manipulate, enhance, and transform images. Many image editing programs are also used to render or create computer art from scratch. The term "image editing" usually refers only to the editing of 2D images, not 3D ones.

References

  1. Colleen Doran (8 November 2007). Manga Pro Superstar Workshop: How to Create and Sell Comics and Graphic Novels. IMPACT. pp. 14–. ISBN   978-1-58180-985-5 . Retrieved 2 January 2013.
  2. Freddie E Williams II (1 September 2009). The DC Comics Guide to Digitally Drawing Comics. Random House Digital, Inc. pp. 52–. ISBN   978-0-8230-9923-8 . Retrieved 2 January 2013.