Image Selection and Editing

Content

Image

Image Size

Image Resolution

What is image?

Images may be two-dimensional, such as a photograph, screen display, and as well as a three-dimensional, such as a statue or hologram.

They may be captured by optical devices – such as cameras, mirrors, lenses, telescopes, microscopes, etc. and natural objects and phenomena, such as the human eye or water surfaces.

Image

Any two-dimensional figure such as a map, a graph, a pie chart, or a painting.

In this wider sense, images can also be renderedmanually, such as by drawing, the art of painting, carving,

Or rendered automatically by printing or computer graphics technology, or developed by a combination of methods, especially in a pseudo-photograph.

In Visual Study: Photo or picture that is taken by any types of camera.

Image

Image editing

Image editing encompasses the processes of altering images, whether they are digital photographs, traditional photochemical photographs, or illustrations.

Traditional analog image editing is known as photo retouching, using tools such as an airbrush to modify photographs, or editing illustrations with any traditional art medium.

Image editing

Graphic software programs, which can be broadly grouped into vector graphics editors, raster graphics editors, and 3D modelers, are the primary tools with which a user may manipulate, enhance, and transform images.

Many image editing programs are also used to render or create computer art from scratch

Editing

Editing

Traditionally

(Analog Image)

DSLR CameraGraphic Software

Image Size

Image size and resolution

• Image size refers to the resolution of the image.• Resolution is sometimes identified by the width and

height of the image as well as the total number of pixels in the image.

• For example, an image that is 2048 pixels wide and 1536 pixels high (2048X1536) contains (multiply) 3,145,728 pixels (or 3.1 Megapixels). You could call it a 2048X1536 or a 3.1 Megapixel image.

• As the megapixels in the pickup device in your camera increase so does the possible maximum size image you can produce.

• This means that a 5 megapixel camera is capable of capturing a larger image than a 3 megapixel camera

Compress or uncompressed

In addition to image size, the quality of the image can also be manipulated

An uncompressed image is saved in a file format that doesn't compress the pixels in the image at all.

Formats such as BMP or TIF files do not compress the image. If you want to reduce the "file size" (number of megabytes required to save the image), you can choose to store your image as a JPG file and choose the amount of compression you want before saving the image.

Compressed Image

Slightly compressed spider image Over compressed spider image

JPG COMPRESSION

JPG compression analyzes images in blocks of 8X8 pixels in size and selectively reduces the detail within each block. At higher compression rations, the block pattern becomes more visible and there may be noticeable loss of detail, especially when you attempt to make prints larger than recommended.

The subject and pattern in the image is also a factor. For example, a picture of the blue sky can be compressed quite a bit without any noticeable effects but a picture of a colorful bird would "pixelate" quite quickly. Take another look at the two images at the top. The first is somewhat compressed, about 200 pixels high (size) and the file is only 14Kb. The image on the right is the same size but compressed quite a bit more reducing the file size to 4Kb.

By using JPG compression, you can keep the physical size of the image the same and reduce the amount of disk space required to store it but you will be sacrificing the quality of the image.

Resolution

Image resolution is the detail an image holds. The term applies to raster digital image s, film images, and other types of images..

Image resolution can be measured in various ways. Basically, resolution quantifies how close lines can be to each other and still be visibly resolved.

Resolution Illustration

Pixel resolution

Resolution is the capability of the sensor to observe or measure the smallest object clearly with distinct boundaries.

There is a difference between the resolution and a pixel. A pixel is actually a unit of the digital image. Resolution depends upon the size of the pixel. With a

given lens setting the smaller the size of the pixel, the higher the resolution will be and the clearer the object in the image will be.

Images having smaller pixel sizes might consist of more pixels. The number of pixels correlates to the amount of information within the image.

Which picture has more pixel?

Higher Resolution?

Thank you…