Aspects of Digital Imaging PDF
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Ms. Rose L. Tulod
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This document is a presentation or lecture about various aspects of digital imaging, including the concept of pixels, resolution, and image file size. It explains fundamental concepts, discusses different image formats, and offers practical examples of calculating or determining image resolution requirements.
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ASPECTS of Digital Imaging Comm22 – Digital Imaging Ms. Rose L. Tulod 1. Explain Digital Imaging 2. Discuss Digital Images 3. Identify the Father of Photography 4. Tell the how Digital Imaging started 5. Application of Digital Imaging in Various fields : Let’s R...
ASPECTS of Digital Imaging Comm22 – Digital Imaging Ms. Rose L. Tulod 1. Explain Digital Imaging 2. Discuss Digital Images 3. Identify the Father of Photography 4. Tell the how Digital Imaging started 5. Application of Digital Imaging in Various fields : Let’s Recall ▪ Education ▪ Business ▪ Media and Communication ▪ Medical ▪ Entertainment UNDERSTANDING PIXEL How many pixels is a digital photo? Today's computer displays typically range from 1024 to 4096 pixels wide by 768 to 3072 pixels high, with 1920 x 1080 being the most common. So, when you are viewing a photo that has larger pixel dimensions than your display, if you're seeing the entire photo, it is being shrunk down to fit your screen. Understanding Image Resolution PIXEL DIMENSIONS Pixel dimensions refer to the horizontal and vertical measurements of a digital image. A digital image’s pixel dimensions may be determined by multiplying the width and height by the amount of pixels-per-inch (ppi/dpi). Digital cameras have pixel dimensions expressed horizontally and vertically to help define its resolution. For scanned images, calculate the ppi/dpi by dividing a document’s dimension into the aligned pixel dimension. For example, an 8-inch by 10- inch document with a 400 ppi/dpi has the pixel dimensions of 3,200 pixels by 4,000 pixels. UNDERSTANDING IMAGE RESOLUTION It is expressed in terms of the number of pixels that can be displayed both horizontally and vertically. Resolution is an important factor to measure the visual quality of digital images, photos and videos. UNDERSTANDING IMAGE RESOLUTION The resolution of a digital image refers to the ability to see its spatial detail-essentially, how clear the image is and how much you can enlarge it without losing quality, or making it look fuzzy. The spatial frequency of a digital image is a good indicator of its resolution. Resolution is often expressed in pixels-per-inch (ppi/dpi). Digital artists can increase the sampling frequency to create sharper resolution. Each pixel can be seen by zooming in on a digital image. 10 With higher resolution, you can zoom in and crop images without losing too much detail. In addition, resolution also determines the maximum size at which an image can be printed or displayed without appearing pixelated or blurry. However, it is important to remember that the resolution of the captured image is limited by both the number of available pixels and the optical resolution of the lens. For example, an image that is 3072 pixels wide and 2304 pixels high contains 7,077,888 pixels (3072 x 2304) or 7 megapixels. This means that a 7 megapixel camera can capture an image larger than that of a 2 megapixel camera. The more pixels in an image, the higher the resolution and the bigger printouts you can make. How would you know how you can make a bigger print without losing image quality? For example, if you have a 3072 x 2304 image that you want to print at 300 PPI (recommended resolution for printing is 200 – 300 PPI), the formula would be: 3072/300 = 10.24 and 2304/300 = 7.68. How would you know how you can make a bigger print without losing image quality? This means you can print the longest side of the image at a maximum of 10.24 inches without having to add new pixels called resampling (upsamplling), which could result in a loss of image quality. RESOLUTION = CLARITY RULING: MORE PIXELS =HIGHER RESOLUTION The more bits per pixel (bpp) means more available colors and the image color will be more accurate. For example, an image with a bit depth of 1 has pixels with only two possible values: black and white (21 = 2). An image with a bit depth of 8 has 256 colors (28 = 256). Images in Grayscale mode with a bit depth of 8 have 256 possible gray values. 20 9/16/2022 Understanding Digital Imaging It refers to the light and dark tonal contrast of an image. It has an impact on the total number of potential shades produced on an image; however, it does not necessarily correlate 100 percent of the time. it is proportional to the pixel dimensions of an image is partially determined by the file format, and it specifically refers to how much disk space your file occupies, either on the hard drive, phone memory or other storage medium. Image files normally range in sizes measured in Kilobytes (KB or K) and Megabytes (MB or M); extremely large files may be measure in Gigabytes (GB). The file size is usually represented in increments of 1,024 or more. For instance: 1 byte = 8 bits 1 kilobyte (KB) = 1,024 bytes 1 megabyte (MB) = 1024 kilobytes (KB) 1 gigabyte (GB) = equals 1,024 megabytes (MB) 1 terabyte (TB) = 1,024 gigabytes (GB) As a general rule Web images should fall between 10 and 200K; images with larger file sizes will load more slowly, and generally be too cumbersome for effective computer distribution and display. Images for print will have larger file sizes, since higher resolution = more data stored in the file. Images for Web or computer display will have smaller file sizes. it is the process of reducing an image’s file size in order to store, process, and transmit it. File Formats contain bits of information that consist of the image and header. The file format tells the computer how to read and interpret the file. There are many types of file formats that vary in color capabilities, bit-depth, resolution, compression, and metadata. 1. Choose 3 pics/photos images on your phone. 2. Check and Identify the details of each: ▪Image Resolution /Dimensions ▪File Size ▪File Format ▪Filename 3. Answer the ff: -Is your photo no. 1 can fit it to a display or screen resolution of 1024 x 768? Will it be distorted or will work fine? -What will be the maximum paper size you can print your 2nd photo at 300 ppi/dpi? -In terms of dynamic range , is your photo no 3. has brighter or darker parts ? Put your answers in a Word file. Submit using the filename Surname_FirstName(Initial only)_ Activity 2 Work It Out Activity 2 Thank You!