Digital Signal Transmission/Applications for Multimedia Files - Revision history

Guenter at 11:54, 17 April 2023

2023-04-17T11:54:11Z

Guenter at 10:21, 5 April 2023

2023-04-05T10:21:20Z

Guenter at 10:21, 5 April 2023

2023-04-05T10:21:01Z

Guenter at 10:19, 5 April 2023

2023-04-05T10:19:47Z

Guenter at 12:27, 19 October 2022

2022-10-19T12:27:48Z

Hwang at 12:31, 18 October 2022

2022-10-18T12:31:05Z

Hwang at 12:26, 18 October 2022

2022-10-18T12:26:11Z

Hwang at 12:22, 18 October 2022

2022-10-18T12:22:49Z

Hwang at 08:46, 1 October 2022

2022-10-01T08:46:32Z

Hwang at 08:09, 1 October 2022

2022-10-01T08:09:15Z

@@ Line 114: / Line 114: @@
 <br clear=all>
 For the four right images, transmission errors with the (average) error probability&nbsp; $p_{\rm M}  = 1\%$&nbsp; are considered in each case. One recognizes:
-[[File:EN_Dig_T_5_4_S4.png|right|frame|Influence of burst errors on BMP files '''KORREKTUR: bzw.'''|class=fit]]
+[[File:EN_Dig_T_5_4_S4.png|right|frame|Influence of burst errors on BMP files|class=fit]]
 *The errors in image&nbsp; $\rm B$&nbsp; are statistically independent and were generated according to the&nbsp; [[Digital_Signal_Transmission/Binary_Symmetric_Channel_(BSC)|"BSC model"]].&nbsp; They are randomly distributed over the whole image area.<br>

@@ Line 11: / Line 11: @@
 Essential properties of BMP images are:
-*A bitmap is a matrix of pixels, whose individual elements are also called pixels&nbsp; $($"picture Elements"$)$. The pixels are stored line by line, from bottom right to top left.<br>
+*A bitmap is a matrix of pixels, whose individual elements are also called pixels&nbsp; $($"picture elements"$)$. The pixels are stored line by line, from bottom right to top left.<br>
 *Each pixel is also assigned an RGB color value from the additive primary colors&nbsp; "$\rm r$ed",&nbsp; "$\rm g$reen" &nbsp;and&nbsp; "$\rm b$lue". &nbsp; The larger the color value can be, the finer the colors to be displayed can be graded.<br>

@@ Line 11: / Line 11: @@
 Essential properties of BMP images are:
-*A bitmap is a matrix of pixels, whose individual elements are also called pixels (<i>Picture Elements</i>&nbsp;). The pixels are stored line by line, from bottom right to top left.<br>
+*A bitmap is a matrix of pixels, whose individual elements are also called pixels&nbsp; $($"picture Elements"$)$. The pixels are stored line by line, from bottom right to top left.<br>
 *Each pixel is also assigned an RGB color value from the additive primary colors&nbsp; "$\rm r$ed",&nbsp; "$\rm g$reen" &nbsp;and&nbsp; "$\rm b$lue". &nbsp; The larger the color value can be, the finer the colors to be displayed can be graded.<br>

@@ Line 73: / Line 73: @@
 A series of images is used to illustrate the effects of transmission errors within the file header (0x00 ... 0x0D) and information block (0x0E ... 0x35). The left figure shows the hexadecimal dump of the falsified file compared to the original file (right).<br>
-[[File:EN_Dig_T_5_4_S2a_v2.png|center|frame|Hexdumps of the falsified file and the original file '''KORREKTUR: falsified'''|class=fit]]
+[[File:EN_Dig_T_5_4_S2a_v3.png|center|frame|Hexdumps of the falsified file and the original file|class=fit]]
 Below you can see the images that result when the five error blocks are successively corrected:

@@ Line 8: / Line 8: @@
 == Images in BMP format ==
 <br>
-One of the oldest image formats is the so-called&nbsp; '''bitmap format'''. Corresponding files are marked with the extension "bmp".
+One of the oldest image formats is the so-called&nbsp; "'''bitmap format'''".&nbsp; Corresponding files are marked with the extension "bmp".
 Essential properties of BMP images are:

@@ Line 57: / Line 57: @@
 *0x22 ... 0x25 (4 bytes)&nbsp;&nbsp;&nbsp;Size of bitmap in bytes:&nbsp;&nbsp;&nbsp;0x 02 DE 62&nbsp;&nbsp;&nbsp;&#8658;&nbsp;&nbsp;&nbsp;188002d,<br>
-*0x26 ... 0x29 (4 Byte)&nbsp;&nbsp;&nbsp;Horizontal resolution in pixels/meter:&nbsp;&nbsp;&nbsp;0x 26 70&nbsp;&nbsp;&nbsp;&#8658;&nbsp;&nbsp;&nbsp;9840d,<br>
+*0x26 ... 0x29 (4 bytes)&nbsp;&nbsp;&nbsp;Horizontal resolution in pixels/meter:&nbsp;&nbsp;&nbsp;0x 26 70&nbsp;&nbsp;&nbsp;&#8658;&nbsp;&nbsp;&nbsp;9840d,<br>
-*0x2A ... 0x2D (4 Byte)&nbsp;&nbsp;Vertical resolution in pixels/meter: &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;0x 26 70&nbsp;&nbsp;&nbsp;&#8658;&nbsp;&nbsp;&nbsp;9840d,<br>
+*0x2A ... 0x2D (4 bytes)&nbsp;&nbsp;Vertical resolution in pixels/meter: &nbsp;&nbsp; &nbsp;&nbsp;&nbsp;0x 26 70&nbsp;&nbsp;&nbsp;&#8658;&nbsp;&nbsp;&nbsp;9840d,<br>
-*0x2E ... 0x31 (4 Byte)&nbsp;&nbsp;&nbsp;Number of colors used,<br>
+*0x2E ... 0x31 (4 bytes)&nbsp;&nbsp;&nbsp;Number of colors used,<br>
-*0x32 ... 0x35 (4 Byte)&nbsp;&nbsp;&nbsp;Number of important colors.<br><br>
+*0x32 ... 0x35 (4 bytes)&nbsp;&nbsp;&nbsp;Number of important colors.<br><br>
 Then the '''image data area''' begins with "0x 43 2A 23" (in the example three bytes per pixel each for R &ndash; G &ndash; B). Since also here (with the Intel processor) the <i>little&ndash;endian byte order</i> applies, these entries designate the color values&nbsp; $\rm R = 23$,&nbsp; $\rm G = 2A$,&nbsp; $\rm B = 43$&nbsp; (in each case hexadecimal) or &nbsp; $\rm R = 35$,&nbsp; $\rm G = 42$,&nbsp; $\rm B = 67$&nbsp; (decimal) .<br>

@@ Line 40: / Line 40: @@
 *0x0A ... 0x0D (4 bytes)&nbsp;offset (start of image data): 0x 00 00 00 36&nbsp;&nbsp;&nbsp;&#8658;&nbsp;&nbsp;&nbsp;54d.<br><br>
-<i>Note:</i> &nbsp;However, these specifications only apply to the Intel processor, which reads according to the so-called &nbsp;<i>little&ndash;endian byte arrangement</i>&nbsp; from the least significant byte &nbsp;(LSB)&nbsp; to the most significant byte &nbsp;(MSB).&nbsp; The arrangement "98 DE 02 00" of bytes 2, ..., 5 is thus to be interpreted as "0x 00 02 DE 98", which corresponds to the decimal number "188056".<br>
+<i>Note:</i> &nbsp;However, these specifications only apply to the Intel processor, which reads according to the so-called &nbsp;<i>little&ndash;endian byte order</i>&nbsp; from the least significant byte &nbsp;(LSB)&nbsp; to the most significant byte &nbsp;(MSB).&nbsp; The order "98 DE 02 00" of bytes 2, ..., 5 is thus to be interpreted as "0x 00 02 DE 98", which corresponds to the decimal number "188056".<br>
 The '''40 byte information block''' contains the following values (bytes with the content "00" are not specified here):

@@ Line 124: / Line 124: @@
 *A comparison of images&nbsp; $\rm D$&nbsp; and&nbsp; $\rm E$&nbsp; shows the different correlation durations related to pixels&nbsp; $(D_{\rm K} \approx 95$&nbsp; versus &nbsp;$D_{\rm K} \approx 95/24 \approx 4)$. It can also be seen that in image&nbsp; $\rm E$&nbsp; the error pixels are colored.<br><br>
-== Effects of transfer errors on audios ==
+== Effects of transmission errors on audios ==
 <br>
 The [https://en.wikipedia.org/wiki/WAV "WAVE file format"] is a container format for digital storage of audio data, based on the ''Resource Interchange File Format'' (RIFF) defined by Microsoft for Windows. The file header of WAVE files, which requires special protection, comprises &nbsp;$43$ bytes.