Act profile is excellent. Comparison of GCR and UCR - color separations in Adobe Photoshop

It became possible to optionally take a written test (a month later, a similar section appeared in the SAT). All four-year colleges and universities accept ACT scores, but some may also require additional academic records.

Functions

ACT, Inc. reports that the ACT exam measures a student's general knowledge and ability to perform college-level tasks entering high school through tests in a variety of areas: English, math, reading and science. An optional written test shows the ability to correctly structure your speech and write short essays. The ACT core scores can provide an indicator of college readiness, and scores on each of the subtests indicate a basic level in English, algebra, social studies, humanities, or biology.

Usage

The ACT is most often taken by students from the Midwest and Southern states, while the SAT is more popular on the East (although the ACT previously prevailed there) and West coasts of the United States. The use of ACT scores by schools has increased as a result of much criticism of the competitor. Mensa Society, organization for people with high IQ, also accepts ACT scores (through September and a score of 29 or higher) for admission to the society. The Triple Nine Society accepts scores of 32 or higher for exams taken before October 1989, and scores above 34 for exams taken later.

Structure

Most of the ACT consists of four-choice tests. Subject tests: English, mathematics, reading and scientific reasoning. Each subject test is scored on a scale from 1 to 36 points. English, math, and reading tests also have additional scores ranging from 1 to 18 (they are not related in any way to the overall subject test score). The “overall result” is the sum of all four tests. Additionally, you can take a written test, which is graded on a scale from 2 to 12 points, the combined result for the written test and the English language test varies from 1 to 36. Also, from one to four comments to the essay from the examiners can be attached. The written test does not affect the overall result.

For each correct answer, one point is awarded on the “temporary score”; points are not deducted for incorrect answers. To improve the test results, a student can retake it; according to statistics, 55% of those who retook the ACT improved their score, 22% remained the same, and 23% did worse than before.

English

The 75-question test contains 5 passages of text with some underlined sentences on one page and the underlined parts on the other. One part of the questions focuses on text formatting and punctuation - commas, apostrophes, colons, etc. The other part tests rhetorical abilities - style (clarity and conciseness) and text organization. The test lasts 45 minutes.

Mathematics

Consists of 60 test questions, of which:

14 assess basic knowledge of mathematics
10 - elementary algebra
9 - intermediate level of algebra
4 - elementary trigonometry

Calculators are allowed, but, unlike the SAT, programmable ones are not allowed. The test lasts 1 hour, but the ACT only has tests with five answer options instead of four.

Reading

Consists of 40 comprehension questions on four presented passages (taken from books and magazines):

The first is a part of a literary work (short works and novellas)
The second concerns social (history, economics, psychology, political science and anthropology) sciences
The third concerns the humanities (art, architecture, dance) sciences
The fourth relates to the natural sciences (biology, chemistry, physics)

The test lasts 35 minutes.

Scientific thinking

Scientific Reasoning is a 35 minute test with 40 questions. The questions test the ability to interpret, analyze, evaluate, reason, and solve problems. 7 excerpts of scientific texts are given (on biology, geography, chemistry and physics). Almost all of the passages are taken from scientific research, but one of them is the opposing points of view of several different scientists on a phenomenon. For each passage, where the material is sometimes difficult to understand, there are 5-7 simple questions. In general, the test has three directions:

Written test

The written test is always given at the end of the exam and lasts 30 minutes. All essays must be on a specific topic, usually social. The written test does not affect the overall result. Instead, a joint English Test/Written Test result has been created. If a student writes an essay poorly, this combined score will drop by a maximum of 2 units. The specific structure of the essay is not defined.

Two trained employees evaluate the work from 1 to 6 points, “0” is given if the essay is not written, is not in English, is not written with a No. 2 pencil, or it is impossible to understand what is written. The final result is the sum of two assessments. If the scores of two inspectors differ by more than one point, then a third is appointed, who will determine the final result.

Although this test is optional, many schools require it for admission and the essay score may influence admissions decisions.

Results

The average overall ACT score is 18, with a standard deviation of 6 points either way, but this statistic varies from year to year.

Below is a table of average results for 2009.

Taking the test

Notes

American Mensa | Qualifying Test Scores Archived July 21, 2011.

Evgeny Kuznetsov,

S> UCR is an image drawn with three CMY colors, S> with shadows emphasized by black paint. S> GCR - an image drawn with black S> paint and decorated with three CMY colors. Quote from the printing forum

I wouldn’t simplify it that way, and, for my part, I’ll try to bring some clarity to this issue.

Firstly, both GCR and UCR performed by Adobe Photoshop are simply different sides of the same process - color separation; accordingly, they work somewhat similarly, although they achieve (depending on the current settings) different results.

First, about the terminology, and, in particular, I will give a decoding of the abbreviations UCR and GCR.

UCR(Under color removal) in the general case actually deals with the partial replacement of process colors with one black paint. This is done in the shadow areas of the image: where there is a fairly large percentage of the total paint content. De facto, at the output of the color separated image we get “VERY SKELETAL BLACK”, which is contained only in deep shadows, forming, as it were, the skeleton of the image, its outline, emphasizing deep shadows (hence the name).

GCR(GRAY COMPONENT REPLACEMENT) also actually replaces process inks in proportions that meet the gray balance conditions for a given triad color scheme (in accordance with the type of inks accepted by the "Printing inks" option) with one REPLACEMENT black ink. In fact, the GCR color separation algorithm in Adobe Photoshop is similar to UCR, the only difference is the nuances of the settings of the remaining options available in CMYK Setup - Custom CMYK. De facto, at the output of a color separation image when using the GCR / Light or Medium color separation algorithm, we obtain a “skeletal” black color in the corresponding black channel. Depending on the Black generation settings, we can also get black, which is contained not only in deep shadows, but also in lighter areas of the image (for example, in 3/4-tones or midtones of the image).

That is, in Adobe Photoshop notation, GCR and UCR are identical, the point is the possibility of settings. In fact, by combining color separation parameters or manipulating the black generation curve while in GCR mode, we can achieve the same result as UCR color separation.

Now - more about the differences between these modes. Everyone probably noticed that when you select the GCR color separation type, several more options become available (in particular, black generation - “Black generation” and “UCA amount”), and when you select UCR, they become inactive. This is actually the point - UCR is actually a special case of GCR color separation, in which the Black Generation and UCA options are not relevant.
In any case, when choosing GCR color separation, we simultaneously select one or another level of black generation (Black generation) in the range from None to Maximum. This determines how dark the image must be so that instead of the triad or in addition to it, black paint appears. For example, Black generation - Light determines that black paint will appear if the content of the so-called “staining (polluting) component” in the main color built with process paints is at least 40%. This, for example, could be 40% Yellow in the 100C+100M binary, or 40% Cyan in the 100% Magenta + 100% Yellow binary. That is, below this 40% (for example, in the case of 30% yellow in the 100Cyan + 100Magenta binary), black paint will not be generated instead of the triad, but above it it will be. In fact, a certain “triggering threshold” of the color separation algorithm is determined, and our task comes down to determining the threshold of this triggering.

Just in case, I will give the meanings of these “thresholds”:

Light - 40% and above;

Medium - 20% and above;

Heavy - 10% and above;

Maximum 0% and above; in this case, even one percent “staining” additives will be replaced with black paint in the main color throughout the entire image.

Fig.1. Color separation modes in Adobe Photoshop and corresponding black ink generation curves

By the way, all these percentages can always be “seen” in the same Adobe Photoshop, taking as a basis any level of black paint generation, and then selecting the “Custom” option there.
From a user's perspective, Light provides the most triad and the least amount of black, while Maximum is the exact opposite - the least triad and the most black. From the point of view of a color corrector, the Light mode will produce the largest color gamut, and Maximum (and similar Black Generation values: for example, Heavy) will produce some narrowing of the gamut. And from the printer’s point of view, it will be more difficult to maintain the gray balance when printing images “divided” in CMYK using Black generation: Light than images that have undergone color separation, for example, with Black Generation: Heavy, since in the first case in neutral gray areas of the images will have more of a triad, and any fluctuations in print densities/dot gain will cause the image to go out of balance.

UCR also provides for setting some levels of black generation, but they are not EXPLICITLY set - in fact, UCR is closest to GCR/Light color separation, since it provides a large amount of triad and a small amount of black ink (and, as a result, maximum color gamut - minimal stability gray balance). With the difference that in GCR/Light the “reactivity level” is 40%, and in UCR it is about 60%. That is, it turns out not just “skeletal”, but “very skeletal” black.

For the same reason, when selecting UCR, the UCA Amount option becomes unavailable. As you know, the UCA parameter ("Under color addition" or "Under color adjustment" - I've seen both versions of this abbreviation) controls the addition of process colors in the proportions of the "current" gray balance into the shadow areas of the image.
Typically, UCA is used to maintain the densities of those shadows that, as a result of strong subtraction (which happens with GCR/Heavy and GCR/Maximum), turned out to be too gray and, accordingly, not dense enough. Since UCR provides even lower black generation than GCR/Light (and, accordingly, less black subtraction), the UCA option becomes unnecessary when using it.
Once again, I want to clarify that all of the above is relevant for the Custom CMYK menu in modern versions of Photoshop, and to a greater or lesser extent reflects the characteristics of the corresponding color separation modes in other applications, but does not display all possible cases of controlling image color separation. Therefore, Adobe Photoshop should not be considered an ideal tool for creating ICC profiles and, accordingly, a tool that allows you to redefine all color separation parameters. To fully describe this process, Photoshop lacks options such as Black Start And Black Width, which exist in other, more advanced tools for creating ICC profiles (see Fig. 2.).

Fig.2. An example of a description of options for controlling black generation parameters in the GretagMacbeth ProfileMaker 5.x environment
For my part, I thank Alexander Pylsky for the constructive criticism expressed when writing this article.

Did you find the article useful and would you like to receive additional information? We invite you to study at our training center. We conduct high-quality courses and trainings for color correctors, designers, pre-press specialists, printing and advertising managers, and other printing professionals. Professional trainings with on-site visits to students in Kyiv, Ukraine, or throughout the CIS and beyond.

Functions

ACT, Inc. reports that the ACT exam measures a student's general knowledge and ability to perform college-level tasks entering high school through tests in a variety of areas: English, math, reading and science. An optional written test shows the ability to correctly structure your speech and write short essay. The ACT core scores can provide an indication of college readiness, and scores on each of the subtests provide an indication of basic English proficiency. algebra, social sciences, humanities or biology.

Usage

The ACT is most often taken by students with Midwest and southern states, while SAT more popular on the east (although ACT previously prevailed there) and west coasts USA. The use of ACT scores by schools has increased as a result of much criticism of the competitor. Society Mensa and High IQ society also accept ACT scores (pre-September and at least 29 points) upon admission to the society. Triple Nine Society accepts scores of 32 or higher for exams taken before October 1989, and scores above 34 for exams taken later.

Structure

For each correct answer, one point is awarded on the “temporary score”; for incorrect answers, unlike SAT, points are not deducted. To improve the test results, a student can retake it; according to statistics, 55% of those who retook the ACT improved their score, 22% remained the same, and 23% did worse than before.

English

The 75-question test contains 5 passages of text with some underlined sentences on one page and instructions to correct the underlined parts on the other. One part of the questions focuses on text formatting and punctuation - commas, apostrophes, colons, etc. The other part checks rhetorical abilities - style (clarity and conciseness) and organization of the text. The test lasts 45 minutes.

Mathematics

Consists of 60 test questions, of which:

14 assess basic knowledge of mathematics
10 - elementary algebra
9 - intermediate level of algebra
4 - elementary trigonometry

Calculators are allowed, but unlike SAT, programmable ones are prohibited. The test lasts 1 hour, but the ACT only has tests with five answer options instead of four.

Reading

Consists of 40 comprehension questions on four presented passages (taken from books and magazines):

The first is a part of a literary work (short works and short stories)
The second concerns public (story , economy , psychology , political science And anthropology) sciences
The third concerns humanitarian (art , architecture , dancing) science
The fourth refers to natural (biology , chemistry , physics) sciences

The test lasts 35 minutes.

Scientific thinking

Written test

Although this test is optional, many schools require it for admission and the essay score may influence admissions decisions.

Results

The average overall ACT score is 18, with a standard deviation of 6 points either way, but this statistic varies from year to year.

Below is a table of average results for 2009.

Taking the test

Notes

Wikimedia Foundation. 2010.

See what "ACT" is in other dictionaries:

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Act-Up

Act-up- Paris Date de création 1989 Réunion hebdomadaire tous les jeudis à 19 h à l École des Beaux Arts 14, rue Bonaparte 75006 Paris Nombre d adhérents 150 revendiqués Site internet … Wikipédia en Français

Act Up- Paris Date de création 1989 Réunion hebdomadaire tous les jeudis à 19 h à l École des Beaux Arts 14, rue Bonaparte 75006 Paris Nombre d adhérents 150 revendiqués Site internet … Wikipédia en Français

act- 1 n 1 a: something done by a person in accordance with his or her free will a tortious act see also actus reus b: the failure to do something that one has a legal duty to do – called also negative act; 2 a...Law dictionary

Act profile is excellent. Comparison of GCR and UCR - color separations in Adobe Photoshop

Functions

Usage

Structure

English

Mathematics

Reading

Scientific thinking

Written test

Results

Taking the test

Notes

Functions

Usage

Structure

English

Mathematics

Reading

Scientific thinking

Written test

Results

Taking the test

Links

Notes

See what "ACT" is in other dictionaries: