23-07-2012, 01:04 PM
IMAGE ENHANCEMENTS
Image Enhancement ppt.ppt (Size: 878 KB / Downloads: 69)
Introduction
Image enhancements encompasses the processes of altering images, whether they be digital photographs, traditional analog photographs, or illustrations.
Traditional analog image editing is known as photo retouching.
Graphic software programs are the primary tools with which a user may manipulate, enhance, and transform images.
Basics of Image Enhancement
Raster images are stored in a computer in the form of a grid of picture elements, or pixels.
These pixels contain the image's color and brightness information.
Image editors can change the pixels to enhance the image in many ways.
Automatic image enhancement
Camera or computer image editing programs often offer basic automatic image enhancement features.
Red eye removal, sharpness adjustments, zoom features and automatic cropping are some of the image editing features.
Digital data compression
Many image file formats use data compression to reduce file size and save storage space.
Some compression algorithms, such as those used in PNG file format, are lossless, which means no information is lost when the file is saved.
By contrast, the JPEG file format uses a lossy compression algorithm by which the greater the compression, the more information is lost, ultimately reducing image quality or detail that can not be restored.
Selection
One of the prerequisites for many of the applications mentioned below is a method of selecting parts of an image, thus applying a change selectively without affecting the entire picture.
Most graphics programs have several means of accomplishing this with more advanced facilities such as edge detection, masking, alpha compositing, and color and channel-based extraction.
Layers
Another feature common to many graphics applications is that of Layers, stacked on top of each other, each capable of being individually positioned, altered and blended with the layers below, without affecting any of the elements on the other layers.
This is a fundamental workflow which enables maximum flexibility for the user.
Image size alterations
Image editors can resize images in a process often called image scaling, making them larger, or smaller.
Image editor programs use a mathematical process called resampling to calculate new pixel values whose spacing is larger or smaller than the original pixel values.
Image Enhancement ppt.ppt (Size: 878 KB / Downloads: 69)
Introduction
Image enhancements encompasses the processes of altering images, whether they be digital photographs, traditional analog photographs, or illustrations.
Traditional analog image editing is known as photo retouching.
Graphic software programs are the primary tools with which a user may manipulate, enhance, and transform images.
Basics of Image Enhancement
Raster images are stored in a computer in the form of a grid of picture elements, or pixels.
These pixels contain the image's color and brightness information.
Image editors can change the pixels to enhance the image in many ways.
Automatic image enhancement
Camera or computer image editing programs often offer basic automatic image enhancement features.
Red eye removal, sharpness adjustments, zoom features and automatic cropping are some of the image editing features.
Digital data compression
Many image file formats use data compression to reduce file size and save storage space.
Some compression algorithms, such as those used in PNG file format, are lossless, which means no information is lost when the file is saved.
By contrast, the JPEG file format uses a lossy compression algorithm by which the greater the compression, the more information is lost, ultimately reducing image quality or detail that can not be restored.
Selection
One of the prerequisites for many of the applications mentioned below is a method of selecting parts of an image, thus applying a change selectively without affecting the entire picture.
Most graphics programs have several means of accomplishing this with more advanced facilities such as edge detection, masking, alpha compositing, and color and channel-based extraction.
Layers
Another feature common to many graphics applications is that of Layers, stacked on top of each other, each capable of being individually positioned, altered and blended with the layers below, without affecting any of the elements on the other layers.
This is a fundamental workflow which enables maximum flexibility for the user.
Image size alterations
Image editors can resize images in a process often called image scaling, making them larger, or smaller.
Image editor programs use a mathematical process called resampling to calculate new pixel values whose spacing is larger or smaller than the original pixel values.