Image dimensions. Enlarging Digital Photos

Dimensions of the image when displayed on the monitor

The dimensions of the image that it will have when printed on a printer

Rice. 2.5. Dialog window Image Size

Notice the two areas where the dimensions are indicated. The top area can only display dimensions in two units: pixels or percentages. Here are the dimensions of the image when displayed on the monitor. Therefore, this area should be used, for example, to prepare an image for use as a desktop picture or for publication on the Internet.

The lower area displays the dimensions that the image will have when printed on the printer. Therefore, this area should be used to determine and set the dimensions of your future printed photo.

If you need to change the image resolution and its geometric dimensions at the same time, then disable the checkbox before making changes Interpolation(Resample Image). Then, when the image is reduced, its dimensions will be increased, and when the resolution is increased, on the contrary, they will be reduced.

ATTENTION!

Reducing the resolution reduces the number of pixels in the image; these pixels are lost forever and cannot be returned by increasing the resolution! So if you have a high quality image, say 300 ppi, you can downsample it to 180 or 72 ppi, but if the original image is low quality, like 72 ppi, you won't be able to upscale it to letterpress quality.

In Fig. 2.6 shows the window Canvas size(Canvas Size), the name of which is in the menu Image(Image). Can also be caused by a key combination ++(on Mac OS ++).

You just need to click on this square

Rice. 2.6. Dialog window Canvas size

This window is designed to change the geometric dimensions of the image; it does not affect the resolution.

Please note the checkbox Relative(Relative). Don't forget to install it before setting new dimensions. If you want to increase the width or height of the image, you should enter a positive number in these fields. To reduce the size, enter a negative number.

It is also convenient to use the switch Location(Anchor), which indicates the direction of resizing. For example, if you need to reduce the height of the image at the top by 2 cm, then in the field Height(Height) you must enter a value of –2 cm when the checkbox is checked Relative(Relative), and switch Location(Anchor) place in the lower middle position. The switch is set by simply clicking on the required square.

You don't know how to increase the size of a picture? This is a very simple task since everything you need is already installed on your computer. Read this tutorial and you'll learn how to resize a photo using 5 simple tools.

Method 1: How to Resize an Image in Microsoft Paint

1. Find and launch MS Paint. It comes pre-installed on all versions of the operating system Windows. Start> All Programs> Accessories> Paint:

1. Drag the image into the Paint window or use Menu > Open (Ctrl + O).
2. In the main menu of the program, find the item “ Resize" and select it:

1. The panel for changing image sizes and proportions will open. You can specify the value in pixels. Don't forget to check the " Maintain proportions" Otherwise the image will be deformed:

1. To increase the size of the picture, click the "OK" button and save the photo.

Adviсe:

• If you can't size your photo without stretching it, you can use the Crop tool to remove unwanted edges. How to do this is described in paragraph 3;
• To open a photo faster, right-click on it and select “ Open with Paint»;
• It is best to save the image in the same format as the original.

Method 2. How to resize an image in MS Photo Gallery

1. If Microsoft Photo Gallery is not installed on your computer ( Start > Photo Gallery), you need to download and install it as part of Windows Essentials 2012;
2. Launch MS Photo Gallery and find your graphic file;
3. Right-click on it and select “Resize...”:

1. Select a ready-made preset: " Small 640 pixels", "Medium 1024", "Large 1280", etc.

1. Click " Resize and save" After you increase the size of the picture, the image will be placed in the same folder, and the original will also remain in it.

Adviсe:

• If you need to set the exact image size, select " Custom" and set the size to the larger side of the photo;
• To resize multiple photos at once, select them while holding down the Ctrl key.

Method 3: How to Resize an Image in Photoscape

You can increase the size of the picture in Photoshop. Or use Photoscape for this.

1. Download Photoscape and install it. Launch the program;
2. Go to the "Editor" tab and find the photo you want to edit:

1. At the bottom of the image there is a button “Resize”, click on it.
2. Set a new photo size. Make sure the option " Maintain aspect ratio" is enabled and press the "OK" button:

1. Save the edited image.

Adviсe:

• If you need to resize multiple images, use the " Batch editor" Add a folder and resize all the photos in it;
• If you don't know the exact size, you can set the "Percentage" of the original size.

Method 4. How to resize an image in IrfanView

1. Install IrfanView - a great tool for viewing and enlarging pictures;
2. Add a photo by dragging it into the program window, or by clicking the first button in the toolbar:

1. Go to the "Image" tab, select " Change size/proportions» ( Ctrl+R);
2. Set the new size in pixels, centimeters, inches, or as a percentage of the original image:

1. Save the image.

Adviсe:

• You can use standard sizes: 640 by 480 pixels, 800 by 600 pixels, 1024 by 768 pixels, etc.;
• To maintain high quality photos, make sure your DPI is set to at least 300.

Method 5. How to resize an image online

1. To resize a picture online, go to PicResize.
2. Click the button Browse" to select a photo. Click " Continue»:

1. Select a percentage of the original image, such as 50% smaller. The tool will display the output image size. Alternatively, you can enter your exact size by selecting " Custom Size»:

For a novice user, the Photoshop program will seem like a magical tool that, with mysterious ease, can change any photo beyond recognition. But how!? Tell! How he does it? What is the mechanism? What happens inside the photograph that it changes in any way, as if it were a chameleon? Nothing complicated, you just need to know what digital photography consists of and what rules apply to it, then everything will fall into place.

Namely, this is the type of graphics that Photoshop works with; it consists of tiny elements - pixels, like any object made of the smallest particles - atoms.

Pixels- these are tiny square-shaped elements that contain information about color, brightness and transparency. The term comes from crossing two English words - picture (image) And element.

A digital image file consists of vertical and horizontal rows of pixels that fill its height and width, respectively. The more pixels an image contains, the more detail it can display. They are elusive to the human eye because they are negligible. You'll have to zoom in a lot to see them:

Pay attention to . The visible part of the image is marked with a red frame. I zoomed in to 1200% on the area where the panda's nose and mouth are. As you can see, the image consists of a set of colored squares. When enlarged, it looks like a patchwork quilt of square pieces.

By looking closely, you can understand the basic principles of image construction:

1. Pixels are square in shape and arranged in a grid in the image (think of a checkered notebook sheet).

2. Squares are always strictly one specific color; they cannot even be a gradient. Even if it seems to you that some square is shimmering in color, then this is nothing more than an optical illusion. Enlarge this area even more and you will see this.

3. A smooth transition between colors occurs due to gradually changing tones of adjacent pixels. Even the line of contact of contrasting colors can contain more than a dozen tones.

Image Resolution

The concept of image resolution is inextricably linked with pixels.

The resolution of a digital photograph is written as follows: 1920×1280. This notation means that the image is 1920 pixels wide and 1280 pixels high, that is, these numbers are nothing more than the number of those very small squares in one row and column.

By the way, if you multiply these two numbers - 1920x1280 (in my example it turns out 2,457,600 pixels), then we get the total number "shreds", of which a specific image is composed. This number can be reduced and written as 2.5 megapixels (MP). You came across such abbreviations when you got acquainted with the characteristics of a digital camera or, for example, the camera in a smartphone. Equipment manufacturers indicate the maximum value that their product is capable of. This means that the higher the MP number, the higher the resolution of future images can be.

So, the higher the resolution, the smaller the pixels, which means the quality and detail of the image increases. But a photograph with a higher resolution will also weigh more - such is the price of quality. Since each pixel stores certain information, as their number increases, more computer memory is required, which means their weight increases. For example, the photo with bears at the top of the article with a resolution of 655x510 weighs 58 KB, and a photo with a resolution of 5184x3456 will take up 6 MB.

Pixel sizes and printing

It is important to differentiate situations when we talk about pixel sizes and their impact on the quality of the photo.

Looking at images on a monitor screen, we see that the pixel sizes are always the same. The computer resolution size is considered 72 dpi.

Note

Please note that when you create a new document in Photoshop, the program offers you exactly this value by default:

When viewing large photographs on a computer, for example, 5184 × 3456, you can feel how detailed it is, there is no grain and no defects, it is bright and clear. But believe me, such a photo is again 72 dots per inch. Just for fun, let’s open the image properties:

A large photo will look great on a computer due to its scale. What is your screen resolution? Obviously not 5184x3456, but smaller. This means that the computer must reduce such a photograph so that it fits entirely on the computer screen. The pixels are compressed and their sizes are reduced, which means great image quality. If you were to view such a photo at its original size, you could easily see blur and fade in the image, as well as hard edges of contrasting details.

Pixel sizes are something that people mostly think about when it comes to printing a photo. Here 72 points may not be enough.

For example, I created a document measuring 655x400 pixels with a resolution of 72 pixels. Look at the column print size:

Photoshop has calculated that an image of 655x400 with a resolution of 72 pixels can be printed on paper measuring 9.097x5.556 inches (in centimeters this is 23.11x14.11)

655 pixels wide divided by 72 pixels per inch = 9.097 inches wide
400 pixels divided by 72 pixels per inch = 5.556 inches in height

It would seem, “Wow! What a big sheet of paper you can print on!” But in fact the photo will look something like this:

Blurred photo, no sharpness or clarity.

Printers are considered high-resolution devices, so in order for photos to print beautifully, you either need to print photos initially at a large size, like mine 5184x3456, or change the number of dots per inch in the range of 200 to 300.

I’ll take the same 655x400 image again, but change the number of pixels to 200, this is what Photoshop writes:

The print size has decreased by almost three times. Our image now prints 200 pixels onto 1 inch of paper.

What happens is that the image will be small, hardly fit into a standard 10 by 15 photograph, but it will be of high quality, clear and detailed.

It turns out that there is a certain minimum resolution for printing photographs. If the picture is initially small in size, as mine was, then there’s nothing to even think about good print quality.

What size should an image be in order to print it beautifully?

Let's say you came back from a vacation from Crimea, or took 100,500 photographs of a child and, of course, want to print something in a photo album (example 1), and make one of the most remarkable ones in the form of a painting on the wall (example 2). Let's figure out what size such photographs should be and whether modern cameras can achieve this.

Example 1

So, as a rule, a photo album contains photos of the size 10×15 cm(in inches this is 3.937×5.906). Now we’ll find out what the minimum photo size should be for everything to print beautifully. For calculations we take a resolution of 200 dpi.

200 pixels per inch x 3.937 inches wide = 787 pixels;
200 pixels per inch x 5.906 inches high = 1181 pixels.

That is, a photograph 10×15 cm = 787×1181 pixels, minimum (!)

And having learned the total number of pixels in this resolution (787 × 1181 = 929447 pixels), rounded to the nearest million, we get 1MP (megapixel). I have already written that the number of megapixels is the most important characteristic of modern cameras. The average number of MP in cameras and smartphones reaches approximately 8 MP.

This means that current technology will easily make it possible to take photographs that are immediately suitable for printing images in 10×15 cm.

Example 2

Now let’s look at the case when you have chosen a photograph and want to hang it on the wall in a frame measuring, say, 30x40 cm (I took the frame size from the IKEA store catalog), I’ll immediately convert it to inches: 11.811x15.748. For this size of photo, I would take the maximum resolution size: 300 dpi, this is already considered professional and the highest quality print (just what you need for a large framed picture). And now the calculations:

300 pixels per inch x 11.811 inches wide = 3543 pixels;
300 pixels per inch x 15.748 inches high = 4724 pixels.

Therefore, your photo must be at least 3543x4724 pixels. We multiply the values ​​and get 16,737,132 pixels or 17 MP!

Thus, to print a photo into a frame, you will need a powerful camera. In this range are already being considered. And this is an expensive and serious type of technology.

In general, you should now be able to understand at least a little how the Photoshop program works and how all these photo editing shenanigans are achieved. Having learned about pixels, their properties and capabilities, this process should no longer seem like magic.

If you notice an error in the text, select it and press Ctrl + Enter. Thank you!