JPEG compression levels in Photoshop and Lightroom. Saving an image in JPEG format is flexible
Definition perfect quality JPEG in both Photoshop and Lightroom can be tricky because we often see two different meanings, from which we are asked to choose. Photoshop offers the user compression levels from 0 to 12 when saving images in JPEG format via the "Save" or "Save As" option, while Lightroom prompts you to select a percentage. Percentages are easier to perceive than numbers from 0 to 12, since it is easier for us to relate 100% to “ best quality Images". It is unclear why Adobe created confusion with the meaning of the numbers, since nowhere in the documentation is there information about what range these same numbers represent.
However, the percentage values we see in Lightroom do not actually represent the actual 0 to 100 values. Adobe simply decided to display the 0 to 12 scale as a percentage. Ultimately, this means that moving from one number to another, for example in the range from 85% to 90%, will not make any difference in compression and image size, while changing from 84% to 85%, on the contrary, will make a significant difference. meaning.
Below are various windows that we are used to seeing. First, you see the window that appears when you click the Save or Save As button and select the JPEG format in Photoshop:
As already mentioned, in this window you can select a value on a scale from 0 to 12. And here is the Lightroom export window:
Here we see information about the degree JPEG compression from 0% to 100%.
Now let's take a look at the table below, where the Photoshop scale values from 0 to 12 are displayed as percentages:
| JPEG Compression Rate in Photoshop | Quality designation in PS | % Equivalent in Lightroom | Test file size | Space savings in % * |
|---|---|---|---|---|
| * Saving disk space presented relative to the file size of the image at 100% quality (27.3 MB) and full resolution (captured by a 20 MP camera) | ||||
| 0 | Low | 0-7% | 2.2 MB | 1240% |
| 1 | Low | 8-15% | 2.4 MB | 1138% |
| 2 | Low | 16-23% | 3.0 MB | 910% |
| 3 | Low | 24-30% | 3.4 MB | 803% |
| 4 | Low | 31-38% | 3.9 MB | 700% |
| 5 | Average | 39-46% | 4.6 MB | 594% |
| 6 | Average | 47-53% | 5.2 MB | 525% |
| 7 | Average | 54-61% | 5.8 MB | 470% |
| 8 | High | 62-69% | 7.8 MB | 350% |
| 9 | High | 70-76% | 9.8 MB | 278% |
| 10 | Maximum | 77-84% | 12.9 MB | 212% |
| 11 | Maximum | 85-92% | 17.6 MB | 155% |
| 12 | Max | 93-100% | 27.3 MB | 0% |
So what does this mean? In general, this means that some numbers have no meaning at all, while others have a significant impact on quality, even with the slightest shift on the percentage scale. That is, choosing a quality of 80% will give you the same result as choosing 77% or 84%. And until you choose 85%, nothing will change. The same applies to 90% - this level of quality is no different from 85%!
Photoshop's Save for Web feature
Photoshop's Save for Web feature works slightly differently from the Save and Save As options discussed above in Photoshop and Lightroom export because it uses a different compression algorithm. Every number from 0 to 100 matters here, and the file size can vary significantly.
What's particularly noteworthy about this feature is that it's optimized for low-resolution files meant to be published on a website. As you can see, there are more options here to customize the JPEG, for example you can choose whether to keep the EXIF data (metadata field) or remove it completely along with the color profile.
Optimal JPEG compression ratio
If you've always selected 12 or 100% quality when exporting JPEG images, you likely have a lot of images that are too large for no apparent reason. The fact is that if you select 100% quality when exporting in JPEG format, minimal compression is used, which leads to huge files. This not only increases your storage space requirements, but also increases the time it takes to upload images to your site and the costs of storage and storage. throughput. While many sites use various algorithms to compress images when loading images, only a few do it well enough. So why waste resources and time constantly uploading images in 100% quality?
For JPEG compression I would recommend using the value 77% V Lightroom, And 10 V Photoshop. These settings allow you to save approximately 200% or more disk space, while maintaining enough detail in the scene, without adding visible artifacts. Occasionally there are situations when streaks in the sky may appear at 77%, so if you encounter such a problem, then increase the quality to 85%, as a rule, this is enough to solve it. I almost never use the values above.
Although, for many photos even 77% may be excessive. If you look at the table above, choosing a quality below 10 saves a lot of space.
If you want to significantly reduce the file size of an image, then try moving the quality level slider to 62% or even 54% and see if you are happy with the result or not. Please note that results will vary from image to image. Some photos will look good on low levels compression, while others do not.
What compression ratio do you use in Lightroom and Photoshop? Share your settings in the comments to this article.
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Discussion: 6 comments
read my comment below) Good luck!
Answer
Some photo sites themselves set the volume or size of the photos that we send there, for example, no more than 700 kB. This must be taken into account during compression. I compress it in two steps with the “smart sharpening” filter. Well, I usually set the quality to 10 or 11 in Photoshop. It’s worse when nothing is said about the file size. So they will compress as they need. For myself personally good photos I keep it in full.
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They helped a lot considering that I’m just starting to use photo shop and don’t know all the nuances.
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I usually compress my photos up to 70%. I save space on hosting and increase page loading time.
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Why indicate quality in %? I specify in Lightroom a resolution of 300 dpi and 4800-5700 pixels for printing, 2400 for a computer (Internet, slide show) and set the file limit to 3 megabytes. I assure you that no one will see the difference between a 3 MB and a 10 MB file on the screen or after printing. The difference can only be seen at high magnification; the picture becomes a little softer. And for showing girls and women, it’s better to limit yourself to 2400 pixels... skin defects are not visible (one retouch is not always enough), pimples, when magnified (they like to look at themselves under a magnifying glass). And after additional processing in Photoshop (I use CC), I save it at level 10 or 11. As a result, the files increase to 3.5-4.5 MB. This is the perfect balance between photo quality and size.
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Thanks for the clear lesson, but here I also want to try working http://photoshop-online.biz/edit_photo/ seems not bad online service, you don’t need to download it, photoshop is no worse than the standards
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Problems with saving files in Photoshop are quite common. For example, the program does not save files in some formats ( PDF, PNG, JPEG). This may be due to various problems, lack of random access memory or incompatible file settings.
In this article we will talk about why Photoshop does not want to save files in JPEG format, and how to deal with this problem.
Solving the problem with saving as JPEG
There are several color schemes to display. Saving to the required format JPEG possible only in some of them.
Photoshop saves in format JPEG images with color schemes RGB, CMYK and Grayscale. Other schemes with format JPEG incompatible.
Also, the ability to save in this format is affected by the bit depth of the representation. If this setting is different from 8 bits per channel, then in the list of formats available for saving JPEG will be missing.
Conversion to an incompatible color scheme or bit depth can occur, for example, when using various actions designed for photo processing. Some of them, recorded by professionals, may contain complex operations during which such conversion is necessary.
The solution to the problem is simple. It is necessary to convert the image to one of the compatible color schemes and, if necessary, change the bit depth to 8 bits per channel. In most cases the problem should be resolved. Otherwise, you should think about the fact that Photoshop is not working correctly. Perhaps the only thing that will help you is reinstalling the program.
Instructions
A beginner should not delve too deeply into the theory, but you should definitely know that JPEG is a format with a compression algorithm. File of this format may have different extensions, for example? .jpeg, .jfif, .jpg, .JPG, or .JPE. It is very convenient because it takes up much less space than a similar image in TIFF format or BMP. Unlike the latter, it has less information about the image. While viewing source file This may not be too noticeable on the monitor, but when printing the photo in a laboratory or processing the result may be of lower quality than formats with complete information.
The way you save JPEGs depends greatly on your needs. Before saving the picture, decide whether you will process it, print it on photo paper, or whether you just need to post the picture on a page on the Internet.
For subsequent processing or printing in the darkroom, save the image at its maximum quality and size. When saving the image you are looking for, open the File menu and select Save as. Select the directory where the file will be saved. Enter the name in the first line, and select the JPEG format in the second line and click the Save button. If you have manipulated the file, a dialog box will pop up in front of you to select the quality of the saved image. You should select the maximum quality using the slider or the corresponding number 12. Confirm your choice by clicking Ok. If you have not manipulated the image, then after saving it, a dialog box with a choice JPEG quality won't open.
When saving a photo for publication on the Internet, modern resources themselves can change the size and quality of the downloaded JPEG. However, in some cases you have to do this yourself. Before saving the picture, change its size by going to the Image menu and selecting Image size. Make sure the Constrain Proportions box is checked. Select a unit of measurement that is convenient for you: centimeters, pixels, inches or millimeters, enter the required value of one of the sides in numbers and click Ok (in most cases, images from 800 to 1500 pixels are used for web pages larger side). Save the result by selecting lower quality. With its values from 8 to 10 and a small image size, visual differences from original size are minimal, but the file size is significantly reduced.
also in Adobe Photoshop There is a special module for optimizing and saving images for web pages, which may be more convenient. From the File menu, select Save for Web. In the dialog box that opens, you will be presented with a window for viewing the saved image and several settings options. Select the 4-up or 2-up tab. The program will present you with four or two possible options optimized image. To save the appropriate one, just click on the picture and click Save. If you are not completely satisfied with the options, then first use the tools located to the right of the image.
Preparation of any digital image readable graphic editor Adobe Photoshop, be it a PSD file, TIF image or “large” JPEG image, for publication on a website, forum or in social networks, as well as for shipment by e-mail. In other words, "japeg" for the Internet. It worked out in rhyme.
Of course, the image formats that Photoshop can read are hardly limited to the three mentioned above. And what’s nice is that most can be converted to JPEG. Regardless of the source format, there are two ways to "japegize" Photoshop. The opportunity to choose is doubly pleasant. Both ways are different. External differences are detected with the naked eye, I will specifically highlight the differences in purpose (“Which path to follow?”).
In this tutorial I will introduce two step by step instructions with the necessary theoretical inclusions. It is designed to show you how to optimally save your virtual drawing, collage or photograph in the widely used JPEG format. The latter is most effective for images with smooth color transitions.
To consolidate and expand the acquired knowledge, as well as to develop skills, I have prepared appropriate exercises. I suggest you complete them and then publish your results in the comments to this lesson. Try it in " field conditions"your skill!
First way
1 step
I open the original image in Photoshop. In my case, this is a file called “Example.psd” containing a drawn ball.
On the keyboard I press the key combination “Ctrl”, “Shift” and the key marked Latin letter“S” or select “File” from the main menu (“File”) > “Save As...” (“Save As...”). A dialog box titled “Save As” appears.
Step 2
I choose the location of the future JPEG image. In the “File name” field, enter a new name for the image, if necessary. In the “File type” drop-down list, select the “JPEG (*.JPG, *.JPEG, *.JPE)” format.
I leave the parameters below unchanged, making sure that “standard” sRGB is specified and selected as the color profile embedded in the future JPEG image. If this is the case, then I move on to step 4.
If something else is specified instead of sRGB color profile, such as ProPhotoRGB or AdobeRGB, I will convert the original image to the sRGB color space before starting this tutorial to ensure colors are displayed consistently across most devices. I'll do it this way.
Step 3
I press the “Esc” key on my keyboard to close the “Save As” window.
I select “Image” > “Mode” from the main menu. If the checkbox is checked opposite “8 bits\channel” (“8Bits\Channel”), then select “16 bits\channel” (“16bits\Channel”). Increasing the color depth is desirable so that conversion from one color profile to another occurs accurately. Visually, changes in color depth are unlikely to be reflected in the original and final images.
Then I select “Edit” > “Convert to Profile” from the main menu. A dialog box appears with the title Convert to Profile.
In my case, the original color profile (“Source Space”) that describes the colors in the drawing is called “Adobe RGB (1998)”. I select from the drop-down list " Target profile"("Destination Space") value "sRGB IEC61966-2.1". I check the conversion parameters - they are located below: the “Tool” (“Engine”) parameter is set to “Adobe (ACE)”, “Method (rendering)” (“Intent”) - “Relative Colorimetric”, set There is a check mark next to the “Use Black Point Compensation” option; there is no check mark next to the “Flatten Image to Preserve Appearance” option.
If you increased the color depth (I did this a little earlier), then the “Use Dither” option will be grayed out. If in open image There is only one layer (when you open JPEG images or “simple” TIF images, this is usually the case), then the “Flatten image to preserve appearance” option is also inactive.
I click the “Done” (“OK”) button. The Convert to Profile window disappears.
Step 4
A new dialog box with the title “JPEG Options” appears in the main program window. The “Quality” parameter allows you to set the ratio between the quality of the output image and the amount of space that the image will occupy in the computer’s memory. Thus, the price for reducing volume is the degradation of the quality of the original image. The lower the Quality parameter value, the smaller the size of the JPEG image.
In the example under consideration, I will focus on a value of 6.
To evaluate the quality of the image before saving, I’ll check the box next to the “Preview” parameter.
Step 5
I will set the value of the second parameter - “Format Options” - equal to “Standard Optimized” (“Baseline Optimized”). The volume of the future JPEG image has decreased, but the image quality remains the same.
Step 6
I click the “Done” (“OK”) button in the “JPEG Options” window and check the result.
I compare the volumes of the original PSD image (~ 3000 Kb) and the final JPEG image (82 Kb). Thus, the JPEG file turned out to be approximately 36 times smaller than the original image with visually equal quality. Comfortable!
Please note that the size of the final JPEG image remains the same as the original PSD image, it is 2480 pixels × 2480 pixels.
Second way
1 step
I open the original image in Photoshop.
I press the key combination “Ctrl”, “Alt”, “Shift” and the key designated by the Latin letter “S” on the keyboard, or select “File”> “Save for Web...” from the main menu.
A new dialog box with the title of the same name will appear.
Step 2
Step 3
I set the “Quality” parameter to maximum.
Step 4
I reduce the image size using the “Image Size” parameter.
This is an optional operation, but it helps to significantly reduce the volume of the future JPEG image, most often with minimal losses as. On the one hand, reducing the size will lead to a natural decrease in volume and, on the other hand, to a decrease in detail. The latter, in turn, limits my ability to print the final JPEG image. If I don't plan to print the last one, I'll forget about the restrictions.
IN in this example I enter the value 600 in the “Width” field. The value in the “Height” field will automatically change. Also, the size of the output image will automatically change relative to the size of the original image, specified in the “Percent” field. Changes occur automatically and the “Percentage” field is in an active state if the “Width” and “Height” parameter fields are connected, as evidenced by the corresponding icon located to the right of the named fields.
In the preview window on the left I will evaluate the size and quality of the image. And I can find out the approximate volume of the latter by the number indicated, usually in kilobytes (Kb) or megabytes (Mb) under the left corner of the window.
Step 5
I check the box next to the “Optimized” option.
Step 6
If I want to further reduce the volume of the output image, then I reduce the value of the “Quality” parameter. I recommend sticking to values between 45-90.
IN in this case I'll choose a value of 75.
As a result, on average, with an Internet access speed of one megabit (1 Mbits), the time it takes to download my drawing from the Internet will be one second. It is indicated under the volume value of the future JPEG image.
At the same time, visually the picture turned out to be of quite acceptable quality, the tonal transitions are quite smooth.
Step 7
I check the box next to “Convert to sRGB” and select “Monitor Color” from the drop-down list below.
Step 8
Finally, I check the box next to the “Embed Color Profile” option.
Actions in the 7th and 8th steps are desirable so that the future JPEG image is displayed approximately equally on different devices.
Step 9
In the dialog box that appears with the title “Save Optimized As,” I select the location of the JPEG image and set its name, if necessary. I press in active window"Save" button. Both windows disappear. Now I can evaluate the result.
I close the original image. In the dialog box that appears asking you to save changes, select “No”.
The image obtained by the second method can be conveniently used for publication on the Internet. And the image obtained by the first method can, in addition to publication on the Internet, be printed. Since the size of the image did not change, it was not subject to interpolation, which means its quality is a priori higher than the quality of the image obtained by the second method.
I will tell you more about interpolation and its impact on the degradation of digital image quality in the lesson “What is interpolation?”
To consolidate the knowledge gained, I suggest you not only save several own photos, but also complete the exercises attached to this lesson. The latter cover the challenges you may encounter in your photography career.
Today we will talk about how to properly save and optimize an image in Photoshop and in what format it is best to do this. But right choice saving format greatly affects the quality and appearance pictures, as well as the weight of the picture in kilobytes. This is especially important for those who take into account traffic consumption. So, let's deal with jpg, gif and png in order.
1. In what formats to save pictures?
After you have opened your favorite photo in Photoshop and somehow worked some magic on it or, in general, created a collage of your own from scratch, you have to save this file on your computer. There are three most common formats for saving a file.
jpg format. Perhaps the most common format. Suitable for preserving complex graphic images with many colors and shades and rich texture. That is, it is best to save photographs in this format. Among its disadvantages are that it does not support transparency and is very sensitive to red. 
gif format. This format is very good for saving files with a limited number of colors. For example, text pages, tables, diagrams, logos, simple pictures. It turns out much clearer and weighs less. Plus, the format supports transparency and animation. However, the format is becoming obsolete and is already inferior to the png format. 
png format. Similar to the previous format, but more advanced and compresses images more efficiently. PNG is very convenient for saving clipart to transparent background. Exists in two png-8 formats (for simple pictures, supports 256 colors) and png-24 (for more complex images, supports colors well). 
2. Save using the “Save as...” function
You can save the picture using the old one good way via the menu “File” -> “Save as...” or the key combination “Shift+Ctrl+S”. In the drop-down menu, select the file format in which we want to save the file. (See the picture below) This method is used when the saved image will remain on your computer and is not intended for publication on the Internet. 
3. Save using the “Save for Web…” function
If your picture is intended to be posted on the Internet, then it is better to use the “Save for Web” function. With this method, the image is saved better and of higher quality specifically for the Internet, and plus there are several convenient options. Select “File” -> “Save for Web...” from the menu or the key combination “Alt+Shift+Ctrl+S”. A dialog box will open.
To save an image to jpg format in the drop-down menu (1) select the JPEG format. Set the preservation quality (2) from 75% to 95%. I always give it 75%. Set, if necessary, the required dimensions of the picture (3). The boxes on the left show the original size of the picture (4) and the size of the optimized picture (5). After that, click “Save”. 
In order to save the picture in gif format, in the drop-down menu (1) select GIF format. Select the number of colors to save (2). Set, if necessary, the required dimensions of the picture (3). The boxes on the left show the original size of the picture (4) and the size of the optimized picture (5). After that, click “Save”. 
To save an image to png format In the drop-down menu (1) select the PNG-8 format. Select the number of colors to save (2). Set, if necessary, the required dimensions of the picture (3). The boxes on the left show the original size of the picture (4) and the size of the optimized picture (5). Check the Transparency checkbox (6) to make the background transparent. After that, click “Save”. 
If it is not immediately clear in which mode to save, it is best to try all saving modes, determining by eye the optimal combination of image quality and its weight after optimization. In general, it is useful to experiment with the settings to understand how a particular function works.