Resize photos without losing quality. Increasing the size of a JPEG file using different methods

05.06.2019 Security

Good day, loyal readers and guests of the blog! Today's article is a small tutorial that will explain you how to enlarge a photo without losing quality on a computer. To do this, I have attached some instructions for resizing an image in Photoshop and Paint.NET.

In addition to this, I will also tell you about other applications and online services that allow you to change the scale of graphic files. Let's take a closer look at the material!

Work on the scale of pictures in Paint.NET

Everyone knows the standard Paint program, which allows you to resize images by the number of pixels or by specifying a percentage. However, she cannot keep track of the drop in image quality when scaling it. Therefore, now we will talk about another free raster graphics editor - Pant.NET.

The named editor was created by two students specifically for the Microsoft Windows operating system. Now this is a rather powerful and convenient photo and picture editor that we can use to achieve our main goal - high-quality image enlargement.

To do this, you need to perform a number of actions:

However, do not forget that a very small picture cannot be enlarged many times and still expect a perfectly clear result. At least not with this program. It is suitable for minor changes.

Using the power of Photoshop

I am sure that all of you have heard about this multifunctional and powerful graphics editor. It allows you to solve really complex problems and copes with them perfectly well. The guides I've attached below will work with many popular versions of Photoshop, including CS5 and CS6. Don't forget to increase the canvas size before scaling the file.

So, the first option is to use the "Image Size" command. For this you should:

1. In Photoshop, go to the "Image" tab and select "Image Size";

2. In the dialog box that opens, specify the image dimension in pixels or percentages:

3. Check the boxes next to the last three items: "Scale styles", "Keep proportions" so as not to distort the graphic file, and "Interpolation";

4. And here is the most interesting. Interpolation directly affects the image quality. When the resolution is reduced, some of the pixels are discarded, but when the resolution is increased, the program generates new similar pixels to fill in the missing amount. That's why the output images look blurry

Photoshop offers several interpolation methods:

Nearest pixels. Fast but inaccurate method. It retains sharp edges, which means that when you zoom in on a photo, you may notice stepped lines. More suitable for illustrations.
Bilinear. Interpolates horizontally and then vertically. The output is a smoother image, but the quality leaves much to be desired.
Bicubic. A rather slow method, but more accurate. The tonal gradations at the output are smoother, without visible teeth.
Sharp bicubic. Used to reduce images. Sometimes the sharpness of individual details is exaggerated.
Smoothed bicubic. Just used when enlarging graphic files.
Choose one of them;

5. Click OK.

There is one drawback in this method. If you resize the image several times, its quality will deteriorate significantly, as the program will add and / or remove pixels depending on your actions.

“Is it possible to bypass these negative consequences?” - you ask. Answer: yes. Immediately set the desired size of the old picture or use this “trick with ears”:

In the "File" tab, select "Open as smart object ...";
After that, stretch the image to the desired size;
Press Enter when you're done scaling.

In this case, pixels will not be lost during resampling. And at the end of the graphic file will be slightly blurred.

In any case, you can add contrast and sharpness to increase clarity.

Background for photo enlargement

As already clear, not every photo or image can be enlarged while maintaining the initial level of quality. Apparently, the question of how to increase the size of a photo without losing quality is very resource-intensive, because the reverse process of reducing, on the contrary, only improves the quality.

Here it is worth paying attention that not all applications, programs or applets are designed to perform such operations. In addition, you should separately pay attention to the type of file and the graphics present in it. If the file is converted and saved using bitmap conversion, you don't even have to try to do this. The question of how you can enlarge a photo without losing quality will remain unanswered.

Another thing, if you mean a simple increase in the scale when viewing. There is nothing complicated here.

Initial image characteristics

To begin with, let's turn to standard graphic image viewers.

As a rule, each software product of this type allows you to solve the problem of how to zoom in on a photo without losing quality, using a standard zoom slider or (as in the case of a standard Windows viewer or some other programs) a special tool in the form of a magnifying glass with a plus sign inside the icon.

Some details

True, there are some nuances here. For example, in Windows (regarding the question of how to increase the size of a photo without losing quality in terms of normal scaling), such actions can be performed up to a known limit. It is clear that not all photos, even with the original (standard) resolution of 72 dpi, can be enlarged indefinitely.

Along the way, it is worth adding that the problem of how to enlarge a photo without losing quality directly depends on the initial size, resolution, or even the color depth of the original image. It is probably already clear to many that the smaller the initial image, the more difficult it will be to convert it in terms of resizing or resizing up. You can, of course, try, but, as a rule, nothing good comes of it.

How to enlarge a photo without quality loss: algorithm

Now a few words about how this process will take place. In principle, algorithms that allow you to understand or at least imagine how to enlarge a photo without losing quality come down to several basic aspects.

First of all, this is the definition of the image type. In the case of a raster image, the increase will occur only in terms of the pixel grid. It doesn't suit us. In vector graphics, things are different. By shifting or removing layers, you can achieve a much better result. But that's not all.

Some programs like Asampoo Photo Optimizer do things a little differently. They first perform color correction, then change the darkness or lightness of the image around the edges and inside, after which they build an improvement in photo quality by stretching the overall histogram.

Naturally, for tasks related to how to enlarge a photo without losing quality, you can also use universal packages like Adobe Photoshop, which, by the way, does not care what type of graphics is currently used.

What program to enlarge the photo without losing quality

As for programs for photo processing in this perspective, you can not go far. Ordinary applications like Paint or Picture Manager, included in the standard installation packages of Windows and Microsoft Office of any version, cope with this without any difficulty. Another thing is that the increase in this case can be made up to certain limits.

It is better to use the universal utility Benvista PhotoZoom. Although it is not equal to the same "Photoshop", nevertheless, in some functions it "surpasses" it. In Photoshop, it is recommended to increase the image without losing quality by no more than 10%. The same program involves solving the problem of how to enlarge a photo without losing quality using an indicator that reaches up to 50%, that is, almost one and a half times the original size.

Actually, the application looks much simpler in operation than many professional utilities, and the question of how to enlarge a photo without losing quality is simply elementary. The advantage of this utility is not only that it can convert dimensions without quality loss, but also that there are two main windows, one of which shows a preview, and the second displays a photo in its actual size (or part of the size visible on the screen). This is convenient in the sense that you can always consider the magnification in detail, and change the parameters if necessary.

Interestingly, in scaling, the indicator can reach 400%, but when saving, the original settings will be used. If desired, you can also choose an algorithm for changing the image, but, as practice shows, the built-in S-Spline Max system gives the most tangible and high-quality result.

Conclusion

In principle, when using any method, you can go into its parameters and select those that best correspond to the process that is supposed to be launched. Even the standard set offers any entry-level user or professional a fairly roomy list of features. Naturally, for those who are at least a little versed in editing photos or graphic images, there is a fairly flexible system for changing settings, applying custom filters, and finally, a complete rejection of automation with setting the desired parameters and settings in manual mode. In general, there is something to work on.

You can, of course, use online services, but I think that for the most part they will not give the expected result.

At some point, you may be wondering if how to enlarge a lossless photo for printing. After all, when the image is enlarged, resolution is lost, which will affect the print. I can suggest increasing the size of the cropped image with a product called Genuine Fractals 6. Since I have had experience with Genuine Fractals in the past and have used it for some projects, I decided to write a short article about professional photo enlargement for printing, and in addition to make a comparison between Photoshop and Genuine Fractals 6 Pro enlargement tools.

1. What size is suitable for printing?

One of the most asked questions by photographers who are not very experienced with the printing process is how large can images be printed from their digital SLR camera. The traditional rule of thumb is to divide the image width in pixels by 300 to get the best quality print size in inches. For example, if you are shooting with a Nikon D90 camera, the image resolution will be 4.288 (width) x 2.848 (height). Literally, this means that it has 4,288 horizontal pixels and 2,848 vertical pixels on the image sensor. If you multiply these numbers, you get 12,212,224 pixels, or 12.2 megapixels, the total number of pixels available on the sensor. So in the D90 case above, dividing 4.288 and 2.848 by 300 gives a print size of 14.3 x 9.5 inches. Why do we divide by 300 and what does this number mean? This number represents "DPI" (dots per inch) or "PPI" (pixels per inch) and indicates how many dots/pixels per inch the printer will print on paper. The greater the number of "dots" per square inch, the more tightly and closely spaced the dots will be, resulting in a smoother transition and less space between the dots and ultimately less "grain". 300 dpi produces magazine-quality prints, while lower values below 150 result in grainy and fuzzy printed images.

Given the above information, how big can your printed image taken with the Nikon D90 be? Now that you know what dots per inch mean, the first question to ask is how good a print will be.

Take a look at the following table:

Nikon D90 12.2Mp 300 DPI(highest quality) - 14.3″ x 9.5″

Nikon D90 12.2Mp 240 DPI(good quality) - 17.9″ x 11.9″

Nikon D90 12.2Mp 200 DPI(medium quality) - 21.4″ x 14.2″

Nikon D90 12.2Mp 150 DPI(low quality) - 28.6″ x 19″

If you want the highest quality photo for a 300 DPI magazine publication, you could easily print the full size 8″ x 10″ standard and you can even afford to crop to fit the page perfectly, or print the custom size to 14.3″ x 9.5 ″. Some professional photographers print at 240 DPI and find it good enough for the work they're selling, so you could go a little lower. However, quality below 240 DPI is unacceptable to photographers due to loss of quality and being "unsharp" or "blurry" (if the image is resized incorrectly).

So does that mean you're limited to those small printed shots taken with a DSLR? What if you want to hang your beautiful photo in a 24″ x 36″ frame? That's where proper image resizing can achieve great results.

Printing a photograph in the days of film was fairly easy - photographers already knew the print size of 35mm or medium format film and it was easy to know what size the print would be without much loss of detail and sharpness. With the invention of digital photography, things are different now, sometimes more complicated with all that DPI/PPI language and resizing options with different algorithms. New advances in digital processing now allow for much larger prints with minimal loss of quality and detail. Let's take a look at two of the most used ways to enlarge an image that are used by professionals.

2. Enlarge images withAdobe photoshop

Adobe Photoshop is the most popular graphics program that is used to enlarge images. Photoshop's image enlargement tool is called "Image Size" and is available from the top navigation menu Image -> Image Size. When you open your photo and go to Image Size you will see something like this:

The original width and height indicate the size of the image loaded into Photoshop. In the example above, I took a 1024 x 768 photo and scaled it up by a factor of 4 by changing the width to 4096 (the height changes automatically because I selected the "Keep Aspect Ratio" option). Since I've increased the size, the middle section indicates that if I print this photo at 240 DPI, I'll get a size of 17.067″ x 12.8″. If I change the value from 240 to 300 DPI, the print settings are reduced to 13.653″ x 10.24″ while maintaining the same image size.

Let's move on to a real-life example and see what happens when you zoom in on a photo with Photoshop. I chose a picture of a bird that I took a little earlier this year:

Camera settings NIKON D3S @ 300mm, ISO1400, 1/1600, f/7.1

It has a lot of detail and is very sharp, so it's a great test case. This is what the image looks like at 400% scale:

As you can see, it is "pixelated", which means that it has a lot of squares. This is because the original image is made up of pixels, and when you increase the size, the only thing the computer can do is increase the number of pixels that make up one pixel. In the example above, approximately 4 pixels now represent a single pixel because the image is viewed at 400%, hence "pixelated". If you did the same for print, it wouldn't look good with all those squares. To deal with this problem, Adobe has come up with several image interpolation algorithms that transform square pixels and provide a smooth transition for both upscaling and downsizing an image. However, Adobe strongly recommends that you do not upsize your photo, as extra pixels are created by analyzing adjacent pixels and choosing an average color for a smooth transition, resulting in washed out details. Take a look at the following image, which was scaled up with Photoshop and the Bicubic (Smooth Gradients) interpolation algorithm:

As you can see, the pixel borders have disappeared and have a smooth transition. However, the borders are too smooth and the image has lost the sharpness that was present in the original image. This is not very noticeable when looking at photos from a distance, but when viewed very close, the lack of sharpness will be obvious. After increasing the size, you can manually add a bit of sharpening, but do it very carefully, as this manipulation can make the image look unnatural.

3. Enlarge images withGenuine Fractals 6

A fairly popular image enlargement tool among photographers is OnOne Software's Genuine Fractals 6 Professional, an advanced software for professional photographers designed specifically for enlarging photos to very large and giant sizes. Compared to Photoshop, it has a more sophisticated algorithm that not only analyzes nearby pixels, but does a decent job of preserving image sharpness and detail. Here's what it looks like:

Using Genuine Fractals 6 is very simple - all you need to do is enter new image dimensions or select dimensions from the Document Size panel, and the program will automatically enlarge and crop it to the specified dimensions. For more control over transitions, the program allows you to select the type of image using the Texture Control panel:

As you can see, I chose "Lots of detail" because I wanted to keep as much detail as possible for the feathers and other areas. Here is how Genuine Fractals transformed the image after I clicked Apply:

NIKON D3S@300mm, ISO1400, 1/1600, f/7.1

Now compare the enlarged image in Photoshop and in Genuine Fractals 6 Pro:

Note the abundance of blur in Photoshop (right) and the relatively well-preserved detail in Genuine Fractals (left). And this is without applying additional sharpening in Genuine Fractals!

4. Enlarge images withBenVista PhotoZoom Pro

Another software package that is very similar in functionality to Genuine Fractals is Benvista PhotoZoom Pro. Here is what this product looks like:

And here is the same image processed in PhotoZoom:

NIKON D3S@300mm, ISO1400, 1/1600, f/7.1

Compared to Genuine Fractals:

BenVista PhotoZoom seems to retain sharpness a bit better than Genuine Fractals, especially where the feathers are. I used the proprietary "S-Spline Max" algorithm to get the result above and selected the "Photo-Detail" preset.

5. Conclusions

If you're thinking about printing your images in large format, you don't have to be limited by the number of pixels on your camera's sensor. As I showed above, you can enlarge images to the desired size using tools and algorithms provided by various manufacturers. I'm sure there are other products on the market that can do the same, so definitely give them a try and see what works best for you. If you want professional-quality printed images, then you should consider buying some great tools like Genuine Fractals 6 Pro or BenVista PhotoZoom, which will allow you to make large format prints while retaining as much detail as possible.

Sometimes it happens that you need to resize an image. The reason for this can be many factors. Firstly, the higher the resolution of the photo, the larger its size, and such files can be problematic to store on the device. Secondly, if you need to upload a photo via the Internet, problems may arise, because some file hosting services have a maximum allowable photo size limit.

That is why in the article we will talk about how to change the resolution of a photo. This may come in handy when working at a computer, so let's get started.

What is permission

First of all, let's understand what permission is. And the term is basically simple: resolution is the number of pixels vertically and horizontally in an image.

As you know, the more photos have the same pixels, the larger its size. However, in our time there are innumerable programs that can reduce the image, thereby reducing its size and without losing quality. Well, now let's talk more about how to change the resolution of a photo.

I would also like to say that when the number of pixels is reduced relative to the original value, the photo will not lose quality, but if the same value is increased, the difference will become noticeable.

Method number 1. Paint

Probably everyone is familiar with the Paint program. But despite its small number of functions, it is able to help in changing the resolution of a photo.

So, let's say you have a photo with a resolution of 3,000 by 4,000, and you want to reduce this number by half. To do this, open Paint. You can use the search by calling it using the Win + Q keys. There, immediately click on "File" and select "Open". In the explorer that appears, specify the path to the desired photo and click "Open".

You now have your photo in front of you. To change its resolution, click "Resize". This button is located on the top panel next to "Select".

Now a small window has opened, in which, first of all, you need to choose in what quantities the size will be changed. There are two options to choose from: pixels and percentages. We choose the first. Now you need to check the “Keep aspect ratio” checkbox, this will prevent the photo from shrinking or flattening.

Now you can start resizing. Since we initially wanted to reduce the photo by half, we enter the value 2000 in the “Horizontal” field. You probably noticed that the “Vertical” field filled in by itself, this is due to the fact that the “Keep proportions” checkbox is checked ".

Now click OK and we can safely save the photo in the new size: "File - Save".

This was the first way to change the resolution of a photo - in Paint, now let's move on to the second.

Method number 2. Adobe Photoshop

Now let's move from small to large, more precisely from Paint to PhotoShop. Of course, these are two, but they are nothing alike, but this approach will not be fundamentally different from the previous one.

So, we begin to figure out how to change the resolution of a photo in Photoshop. First you need to open it. Right after that, click "File" and then "Open" and navigate to your photo.

Now click on the same toolbar item "Image". In the list, select the line "Image size ...". Or you can just press Alt + Ctrl + I.

In the window that appears, immediately check the box next to "Keep proportions." And in the "Dimension" column, select "Pixels" in the drop-down list. Now feel free to resize the photo.

Now you know how to change the resolution of a photo without losing quality using PhotoShop.

Output

As you can see, you don't need to know much to change a photo. Everyone can perform the above manipulations, and in the end you will get what you want: the photo will change, but the quality will remain the same, and the file size will noticeably decrease. We hope this article has given you the answer to your question about how to change the resolution of a photo.

I love to do graphics: draw on a graphics tablet, process pictures and photos in Photoshop and create collages. Sometimes there is a need to enlarge an already finished, but small picture. Usually, after such manipulations, the graphics look blurry due to the fact that pixels are lost. Here's how to enlarge an image without losing quality, we'll talk now.

I tried many different programs for enlarging an image without losing quality, but all of them had a very poor quality image after enlarging. And then one day, already completely desperate to find what I needed, I stumbled upon a foreign site where the program was offered SmillaEnlarger beta version.

Most likely, I would have left there, because. I do not speak foreign languages, but due to the fact that I have a Google Chrome browser, I was offered a translation of this page and in the description I read that

SmillaEnlarger is a small GUI tool (based on Qt) for resizing, especially enlarging high quality bitmaps. (The algorithm used is my own invention)

And I decided to try it too.

You can download the program from the official

Working with the SmillaEnlarger program

We go to the page of the site with this program and press the big green button " Download" (if your page is without translation, then the button is called " Download»).

The program is packaged in an archive that must first be unpacked.

As a result, you should have a folder SmillaEnlarger-0.9.0. Open it and go to the folder SmillaEnlarger.

Find a file in it SmillaEnlarger.exe, and run it.

As you can see, the program does not need to be installed. You can simply run it from this folder.

A program will open in which a picture with a dog is shown for a sample.

Uploading your picture

Set the required parameters:

in the window OutputHeight set the height of the enlarged image.

in the window Writeresultto you can write the preferred name of the enlarged file or leave the same name that it had, only the program itself will add the letter “e” through the bottom hyphen at the end of the name. The file will be saved to the same folder where it was before.

If you want to save the file to a different folder, you must uncheck the box next to the entry. useSourceFolder. Then the button is activated. changeFolder, by clicking on which you can select a different folder on your computer.

Now you can click on the Enlarge & Save button below and in a couple of seconds you will have an enlarged image file in the specified folder. And the quality of the file is quite tolerable.

If you want the file performance to be even better, you can try to choose other parameters.

Parameters of the Smilla Enlarger program

OutputDimensions(Finished picture size)

Specifyzoomfactor(Specify scaling factor)

Specify width of result(Specify the width of the result)

Specify height of result(Specify the height of the result)

fitinsideboundary(Set inner border)

Stretch to fit(stretch)

crop to fit(Crop to be picked up)

Fit inside, add bars(Stick inside, add bars)

Window OutputHeight(Height of displayed image)
Enlarger Parameter(Increased setting)

Default(Default)

Sharp(reinforced)

Painted(tinted)

sharp &noisy(amplified with noise)

Thumbnailpreview(Thumbnail Preview)
size(Size)
Write Result to(Write the result)
In Folder(in folder)
useSourceFolder(Use original folder)
ButtonChange Folder(Change folder)
Enlarge &Save(Enlarge and Save)
Cropping Format(Crop format)

Cropping(Format)
Parameter(Parameter)
Jobs(Work)
Log(Journal)
Help(Help)

I've had enough of the default settings so far.

Video on how to enlarge an image without losing quality using the Smilla Enlarger program:

If you use another program or know a program that enhances the image better, then share with us in the comments below.