Forensics 8

Bitmap images store graphics info as grids of __________, sorts for "picture elements."

Pixels

When you decompress data that uses a lossy compression algorithm, you regain data lost by compression.

False

The two major forms of steganography are ____________________ and substitution.

Insertion

The __________ is the best source for learning more about file formats and their extensions.

Internet

What can investigators learn using Exif format metadata, and how is this data accessed?

Investigators can learn more about the type of digital camera and the environment in which photos were taken. Investigators must use special programs, such as Exif Reader, Irfan View, or ProDiscover, which has a built-in Exif viewer, in order to access the metadata.

compression which does not discard data in compressed files

Lossless compression

____ compression compresses data by permanently discarding bits of information in the file.

Lossy

Select below the utility that is not a lossless compression utility:​

Lzip

When looking at a byte of information in binary, such as 11101100, what is the first bit on the left referred to as?​

Most Significant Bit

The first 3 bytes of an XIF file are exactly the same as a TIF file.

TRUE

Each graphics file type has a unique header value.

True

Graphics files are created and saved in the graphics editor, such as Microsoft Paint, Adobe Freehand MX, Adobe Photoshop, or Gnome GIMP

True

ProDiscover adds a ______ extension automatically on all copied clusters the Recover Clusters function exports.

txt file

graphics based on mathematical instructions to form lines, curves, text, and other geometric shapes

vector graphics

The ______ format is an image format produced by the Nuance PaperPort scanning program.

xif

In simple terms, _____________ compression ​discards bits in much the same way rounding off decimal values discards numbers.

Vector Quantization

a form of compression that uses an algorithm similar to rounding off decimal values to eliminate unnecessary bits of data

Vector Quantization (VQ)

Which of the following is not considered to be a non-standard graphics file format?

.dxf

​Which of the following formats is not considered to be a standard graphics file format?

.dxf

How many bits are required to create a pixel capable of displaying 65,536 different color

16 bits

How many different colors can be displayed by a 24 bit colored pixel?​

16,777,216

What act defines precisely how copyright laws pertain to graphics?

1976 Copywright Act

All TIF files start at offset 0 with what 6 hexadecimal characters

49 49 2A

Which graphics file format below is rarely compressed?

BMP

When using steganography to hide messages, why is it better to change the least significant bits of an image, and how is this detected?

Changing the most significant bit (highest priority bit) on the left will cause a greater change in the pixel's color than changing the least significant bit. Generally speaking, only the last two LSBs in an image can be changed without producing a noticeable change in the shad of the color a pixel displays. To detect a change to the last two LSBs in a graphics file, a steganalysis tool must be used.

The process of converting raw picture data to another format is called _________________.​

Demosaicing

A file format that Japan Electronics and Information Technology Industries Association (JEITA) developed as a standard for storing metadata in JPEG and TIF files

ExiF (exchangeable image file)

A standard JFIF JPEG has a header value of _____________ from offset 0 and the label name JFIF starting at offset 6.

FF D8 FF E0

For all JPEG files, the ending hexadecimal marker, also known as the end of image (EOI), is ____________

FFD9

​For EXIF JPEG files, the hexadecimal value starting at offset 2 is _____________.

FFE1

Most digital cameras use the bitmap format to store photos.

False

collections of dots, or pixels, in a grid format that form a graphic

bitmap images

the process of recovering file fragments that are scattered across a disk

carving

The process of converting raw picture data to another format, such as JPEG or TIF

demosaicing

What format was developed as a standard for storing metadata in image files?

exif

the results of keyword searches that contain the correct match but aren't relevant to the investigation

false positives

What file type starts at offset 0 with a hexidecimal value of FFD8?​

jpeg

The Lempel-Ziv-Welch (LZW) algorithm is used in _____________ compression.​

lossless

Whatkind of graphics file combines bitmap and vector graphics types

metafile

graphics files that are combinations of bitmap and vector images

metafile graphics

less common graphics file formats, including proprietary formats, newer formats, formats that most image viewers don't recognize, and old or obsolete formats

nonstandard graphics file formats

The _____________ format is a proprietary format used by Adobe Photoshop.

psd

Which of the following is not a type of graphic file that is created by a graphics program?​

raster graphics

collection of pixels stored in rows rather than a grid, as with bitmap images, to make graphics easier to print; usually created when a vector graphic is converted to a bitmap image

raster images

Referred to as a digital negative, the _______ is typically used on many higher-end digital cameras.​

raw file format