An automatic camera produces 640 480. Assignments on the topic "Transmission speed, memory capacity, transmission time"
. Information coding, volume and transmission of information: Demonstration version of the Unified State Exam in computer science 2018; State final exam 2018; training versions of the Unified State Exam in computer science, thematic test tasks and tasks from the computer science simulator 2018
✍ Show solution:
- Using the formula for image file volume, we have:
- Let's see what we have already been given from the formula:
Where N is the total number of pixels or resolution, and i— color coding depth (number of bits allocated per 1 pixel)
number of colors = 2 i
\[ i = \frac (I)(N) = \frac (320 * 2^(13))(75 * 2^(12)) \approx 8.5 bits \]
Result: 256
State final exam GVE 2018 (informatics GVE FIPI, task 7):
Produced two-channel(stereo) digital sound recording. The signal value is fixed 48,000 times per second, to record each value is used 32 bit. Recording lasts 5 minutes, its results are written to a file, data compression is not performed.
Which of the following values is closest to the size of the resulting file?
1) 14 MB
2) 28 MB
3) 55 MB
4) 110 MB
✍ Show solution:
I = β * ƒ * t * S
Result: 4
Solution 9 of the Unified State Examination task in computer science (diagnostic version of the 2018 exam paper, S.S. Krylov, D.M. Ushakov):
Produced two-channel(stereo) sound recording with sampling rate 4 kHz And 64-bit resolution. Recording lasts 1 minute, its results are written to a file, data compression is not performed.
Approximately determine size of the resulting file (in MB).
As an answer, indicate the integer multiple of the file size that is closest to 2
.
✍ Show solution:
- According to the formula for the volume of a sound file, we have:
I = β * ƒ * t * S
Result: 4
Solution 9 of the Unified State Examination in computer science, option 1 (FIPI, “Unified State Examination Informatics and ICT, standard exam options 2018”, S.S. Krylov, T.E. Churkina):
The musical fragment was recorded in the format quad(four-channel recording), digitized and saved as a file without using data compression. Received file size 48 MB. Then the same piece of music was recorded again in the format mono with sampling rate 2 times less than the first time. Moreover, when recording again, the music playback tempo was reduced by 2.5 times. No data compression was performed.
Specify file size in MB, received during re-recording. In your answer, write down only an integer; there is no need to write a unit of measurement.
✍ Show solution:
- Let's write down the known data about the two states of the file - before and after conversion:
Result: 15
| Computer Science and Information and Communication Technologies | Preparation for the Unified State Exam | Control training tasks
Control training tasks
Part 1
Task 9
The answers to tasks 1 – 23 are a number, a sequence of letters or numbers that should be written in ANSWER FORM No. 1 to the right of the number of the corresponding task, starting from the first cell, without spaces, commas and other additional characters. Write each character in a separate box in accordance with the samples given in the form.
Example 1
What is the minimum amount of memory (in KB) that must be reserved to be able to store any 64x64 pixel bitmap image, assuming that the image can contain 256 different colors? In your answer, write down only an integer; there is no need to write a unit of measurement.
Example 2
To store an arbitrary raster image of 1024x1024 pixels in size, 512 KB of memory is allocated, and for each pixel a binary number is stored - the color code of this pixel. For each pixel, the same number of bits are allocated to store the code. Data compression is not performed. What is the maximum number of colors that can be used in an image?
Answer: ___________________________.
Example 3
The automatic camera produces raster images of 640x480 pixels. In this case, the size of the image file cannot exceed 320 KB, and no data packaging is performed. What is the maximum number of colors that can be used in a palette?
For completing the task correctly you will receive 1 point. It takes approximately 5 minutes.
To complete task 9 in computer science you need to know:
- I - volume of information
- to store a bitmap you need to allocate memory I = N i bits, where N– number of pixels and i– color depth (encoding bit depth)
- number of image pixels N calculated as the product of the image width and height (in pixels)
- coding depth is the number of bits allocated to store the color of one pixel
- The volume of a music file is calculated using formula I = f*r*k*t, Where f- sampling frequency, r– resolution (encoding depth), k– number of channels, t – playing time
- channel B capacity = f*r*k
Tasks for training
Task No. 1
The automatic camera produces raster images of 640x480 pixels. In this case, the size of the image file cannot exceed 320 KB, and no data packaging is performed. What is the maximum number of colors that can be used in a palette?
Task No. 2
To store an arbitrary raster image of 256×1024 pixels, 64 KB of memory is allocated, and for each pixel a binary number is stored - the color code of this pixel. For each pixel, the same number of bits are allocated to store the code. Data compression is not performed. What is the maximum number of colors that can be used in an image?
Task No. 3
What is the minimum amount of memory (in KB) that must be reserved to be able to store any 512-by-128-pixel bitmap image, assuming that the image can contain 512 different colors? In your answer, write down only an integer; there is no need to write a unit of measurement.
Task No. 4
The musical fragment was recorded in stereo format (two-channel recording), digitized and saved as a file without using data compression. The size of the resulting file is 100 MB. The same piece of music was then re-recorded in mono and digitized at a resolution 3 times higher and a sampling rate 5 times lower than the first time. No data compression was performed. Specify the file size in MB of the resulting rewrite. In your answer, write down only an integer; there is no need to write a unit of measurement.
The author of the assignments is a leading specialist who is directly involved in the development of control measuring materials for the Unified State Examination.
Typical test tasks in computer science contain 14 variants of sets of tasks, compiled taking into account all the features and requirements of the Unified State Exam in 2019. The purpose of the manual is to provide readers with information about the structure and content of the 2019 KIM in computer science, the degree of difficulty of the tasks.
The collection contains answers to all test options, provides solutions to all tasks of one of the options, as well as solutions to problems in part 2.
The manual is intended for teachers to prepare students for the computer science exam, as well as for high school students for self-preparation and self-control.
Examples.
The automatic camera produces raster images measuring 640 x 480 pixels. In this case, the size of the image file cannot exceed 170 KB, and no data packaging is performed. What is the maximum number of colors that can be used in a palette?
Performer A16 converts the number written on the screen.
The performer has three teams, which are assigned numbers:
1. Add 1
2. Add 2
3. Multiply by 2
The first of them increases the number on the screen by 1, the second increases it by 2, the third multiplies it by 2.
A program for performer A16 is a sequence of commands.
How many programs are there that convert the original number 3 into the number 12 and at the same time the program's computation path contains the number 10?
A program's computation trajectory is a sequence of results from the execution of all program commands. For example, for program 132 with the initial number 7, the trajectory will consist of the numbers 8, 16, 18.
Download the e-book for free in a convenient format, watch and read:
Download the book Unified State Examination 2019, Computer Science, 14 options, Model test tasks, Leshchiner V.R. - fileskachat.com, fast and free download.
- I will pass the Unified State Exam, Computer Science, Typical tasks, Leshchiner V.R., Krylov S.S., Ushakov D.M., 2019
- Unified State Examination, Computer Science, grade 11, Preparing for the final certification, Leshchiner V.R., Krylov S.S., Yakushkin A.P., 2020
- Unified State Exam 2020, Computer Science, 16 options, Typical versions of exam tasks from Unified State Exam developers, Leshchiner V.R.
- Computer Science, Unified State Exam, Preparing for the final certification, Leshchiner V.R., Krylov S.S., Yakushkin A.P., 2020
The following textbooks and books.