Manual - Example: JPEG


This chapter shows how to use the Task Designer by an example. All steps which are needed to enter the JPEG-Zig-Zag scan are shown below.

Picture 1: JPEG-Zig-Zag-Scan

The JPEG-Zig-Zag-Scan covers a quadriliteral memoryarea. The stepper runs from left to right and from the upper to the lower side. 8x8 big areas are taken out of the memory-map. These areas are sampled with a zig-zag-pattern.

There are certain ways to implement JPEG Scans. The following example uses five Video Scans and was simulated with the Data Sequencer Hardware.

Follow these steps:

1. Create a new Task

2. Define a Scan Window

3. Enter the five Video Scans

4. Define the Task structure


1. Create a new Task

Picture 2: NEW-icon

Press the NEW-icon of the graphical menu to open the NEW-/RENAME-Applet. This applet contains a textfield. Enter the new name for example JPEG and press the ´New´-button (see picture 3). The applet closes automatically and the entered name is shown in on the right side under ´actual Task´.

Picture 3: enter a new task-name

Now you can define a Scan Window or enter all needed Video Scans.

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2. Define a Scan Window

Picture 4: Scan Window Input Icon

This example of the JPEG-Zig-Zag-Scan needs a Scan Window with just one memory-access. Press the Scan Window Input icon to open the applets for the definition of the Scan Window. It is possible to change the size of the Scan Window with the two sliders ´Size X´ and ´Size Y´ but not necessary. We want a Read/Write memory access. Therefore press the ´RW´-symbol of the graphical menu. Mark the memory position of the Scan Window with your mouse (see picture 5). That´s all. Press the ´Back´-button to leave Scan Window Input.

Picture 5: definition of a Scan Window

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3. Enter the five Video Scans

Picture 6: Video Scan Input Icon

The Video Scan Input is used to define simple Video Scans. To open Video Scan Input press the Video Scan icon (Picture 6) of the graphical menu. All neede applets are opened (see Picture 7). The graphical menu contains several icons to manipulate the Video Scan.

On the right side are the several input fileds for the parameters. You have to define a Video Scan by his edges and the two steppers delta A and delta D. You can write these values directly into the textfields ore use the arrows to decrease or increase the values.

Picture 7: definition of Video Scans

At first you have to define the Video Scan that covers the whole memory area. In this example we use a 64 x 64 big area. Picture 8 shows this Video Scan. Picture 7 shows how these values are filled in the textfields. On the left side you can see a graphic of the entered Video Scan.

Picture 8: first Video Scan

To enter more than one Video Scan press the "add"-button (see Picture 7). You can enter up to 16 Video Scans. Now we need four Video Scans to build the Zig-Zag pattern. The Pictures 9 till 12 are showing these four Video Scans and their values. To change the position of the base (red corners) and the direction of the address stepper (blue arrows) use the different manipulation tools of the graphical menu (see Video Scan Input help for details).

Picture 9: second Video Scan

Picture 10: third Video Scan

Picture 11: fourth Video Scan

Picture 12: fifth Video Scan

Picture 13: Video Scan Check Icon

After you have entered all five Video Scans you have to check them for errors. Press the Check icon to do this. Your broser-window shows you a check-protocol. If errors are found it is possible to try to remove the automatically. In this case a dialog-box is opened which asks you to make an auto-correction. If this fails you have to remove the errors manually.

The check-protocol has to look like this.
The Video Scan Input is finished now. Return to the Task Designer main menu.

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4. Define the Task structure

The five Video Scans defined in the Video Scan Input have to be combined to a complex scan. Therefor you have to enter the Scan Pattern Input. Picture 14 shows the windows which are appearing. The Video Scans one and two have to build a meshed scan. To create a meshed Scan press the button labeld with "meshed" at the bottom of the window (see Picture 14). A green pictogram appears inside the composer area (big window in the middle). On the right side you see an area with the actual scan. This is now the meshed scan. To push a scan inside the meshed scan simply make a double-click on it or use the right-arrow (button between the two areas) to move it from one area to the other.

Make another meshed scan like this and puh video scan three and four inside of it.

These two meshed scans have to be combined to a compound scan. Press the button "compound" to create a new compound scan. Push the two meshed scans inside the compound scan like the Video Scans into the meshed scans before.

This compound scan realizes the Zig-Zag pattern. This pattern is called by an outer scan (scan number one). Therefor you have to create a nested scan. Press the "Nested"-button and push the last Video Scan (no. 0) and the compound scan inside of it.

Now you have to have a structure like it is shown in Picture 14. Watch out for the order of the certain scans. To change the order mark a scan and use one of the two arrows of the graphical menu to change the position.

Picture 14: Scan Pattern Input

Picture 15: Edit / View Icon

Sometimes it is necessary to change some parameters of a scan. Press the Edit / View icon to change between view-mode (default) and edit-mode. In edit-mode it is possible to change some of the parameters like the mode- or first_out-bit and so on.

For this example you have to change the stop-condition of the meshed scan with the number six. Enter edit-mode and mark this scan (click on it ones). The middle window on the left side shows you a graphic like in Picture 16. You change the stop-condition from Video Scan three to four by clicking on Video Scan four. The red stop beneath the scannumber shows you which Video Scan has the stop-condition.

Picture 16: change stop

Picture 17: change base

At last you have to move the inner scans of the nested scan. Every Video Scan has at least one edge which lies on the x- and one edge on the y-axis. Therefor these Video Scans have to be moved on their right position. The values for the five scans are shown in the table below:

Video Scan

old values for Base

new values for Base

 

B0.x

B0.y

B0.x

B0.y

0

0

64

0

64

1

1

7

1

0

2

0

4

0

-2

3

0

0

1

-7

4

5

5

7

-2

Enter edit-mode (if you aren´t already in) and mark one of the Video Scans. Picture 17 shhows you what you see on the left side. Chenge the values of B0.x and B0.y to move the Video Scan. Here it is also possible to change other parameters but be shure of what you are doing.

Every changes are done now and the JPEG-Scan is ready.

Picture 18: Parameterlist Icon

To see all parameters of the JPEG-Scan press the parameterlist icon (this icon is also in the main menu). A parameterlist like this has to come up in your browser-window.

Save your parameters to protect your data.

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