How to Improve the Quality of a JPEG Image

2024 Author: Samantha Chapman | [email protected]. Last modified: 2024-01-31 12:32

The JPEG format (also called JPG) is a compressed file format for storing images that creates small files that are perfect for sharing or posting on the web. However, when you try to zoom in on a JPEG image, it may be grainy or fuzzy. You can improve the visual quality of a JPEG image by precisely and deeply changing its appearance, colors, and contrast level, using an image editor. If you have not signed up for a subscription for Photoshop (since it is a paid product), you can use Pixlr, a free editor that can be used directly through an internet browser. This article explains how to optimize the quality of a JPEG image.

Steps

Method 1 of 2: Using Pixlr

Step 1. Visit the website https://pixlr.com/editor/ using your computer browser

Pixlr is a complete and functional image editor, also used by industry professionals and photo editing lovers. Pixlr is also available in a free web version. If you wish, you can purchase the advanced version of the program by taking out a monthly subscription.

Pixlr E supports images up to a resolution of 4k (3840 x 2160). If you need to work with higher resolution images, you may want to use professional software like Adobe Photoshop instead

Step 2. Click on the Launch Pixlr button E

It is located in the middle right of the page. This is the most complete version of Pixlr that you can use for free to optimize images.

Step 3. Open the image or photo you want to edit

The final quality that the image will have, after your work, largely depends on the initial graphic resolution, that is, on the number of pixels that make up the original image. Pixlr developers recommend starting any project starting from a high resolution image, especially if you need to enlarge a part of it: since increasing the size of a low resolution image will bring out the white space that separates each pixel, the final image may have a distorted appearance. Follow these instructions to upload the image to edit on the Pixlr website:

Click on the button Open Image visible on the left side of the page;
Use the file browser to navigate to the directory of the image you want to open;
Select the image to edit;
Click on the button Open.

Step 4. Resize the image (optional)

The size of a JPEG file is determined by the resolution of the image, that is, by the number of pixels that compose it. The higher the resolution, the larger the file size. Sharing a large JPEG file via email or uploading and downloading from the web is a time-consuming process. Resizing the image, in order to reduce the number of pixels that compose it, will allow you to share or transfer it faster. Note that increasing the size of an image does not increase the visual quality as well. However, reducing the size of an image may also cause a decrease in the number of details. Follow these instructions to resize an image using Pixlr:

Click on the menu Image;
Click on the item Image Size;
Activate the "Constrain proportions" option;
Type the number of pixels you want into the "Width" or "Height" text fields;
Click on the button Apply.

Step 5. Crop the image

This operation allows to remove, in a simple and quick way, the parts of the photo that are not needed. Deleting parts of an image also reduces the size of the corresponding file. The "Crop" tool features a square icon with the sides of two opposite corners overlapping. It is listed at the top of the left column of the toolbar. Follow these instructions to crop an image:

Click on the icon Crop in the toolbar;
Drag the mouse cursor over the area of the image you want to crop and keep;
Click on the button Apply to delete the portion of the image that is outside the selected area.

Step 6. Use the "Clarity" filter

This filter can be used to intensify the details in a photo that has few or to blur them if there are too many. Proceed as follows:

Click on Filter in the menu bar located at the top;
Place the cursor on Details among the menu options;
Click on the option Clarity;
Drag the bar to the right to emphasize details or to the left to reduce them;
Click on Apply.

Step 7. Use the "Blur" or "Sharpen" filters

If "Clarity" isn't enough, you can use the "Blur" or "Sharpen" filters to further emphasize or blur details. "Sharpen" can be used to emphasize, "Blur" to blur image details. Proceed as follows:

Click on Filter in the menu bar located at the top;
Place the cursor on Details among the menu options;
Click on Sharpen or on Blur;
Drag the slider to the right to increase the effect;
Click on Apply.

Step 8. Reduce image noise

The "Remove Noise" filter can be used to remove or reduce dots, grain and such imperfections. Proceed as follows to apply the filter in question:

Click on Filter in the menu bar located at the top;
Place the cursor on Details among the menu options;
Click on the option Remove Noise;
Move the sliders according to your needs as follows:
- Radius - determines the size of the dots that will be reduced
- Threshold - determines the color differences needed to identify the dots to be removed
Click on Apply.

Step 9. Touch up more detailed areas of the image using the "Clone Stamp" tool

It features a stamp icon. You can use this tool to eliminate imperfections or spots in a photo: you simply have to sample the area around the defect to be corrected and replicate it on the latter. Follow these instructions to use the "Clone Stamp" tool:

Click on the tool icon Clone Stamp, visible in the toolbar on the left side of the page;
Click on the item Brush displayed at the top left of the page;
Select a type of brush with soft edges or with the tip of the size you want;
Click on Source in the panel at the top;
Click on an area near the point you want to remove to take a sample of the closest texture;
Click on the imperfection or artifact to be eliminated;
Repeat the process to remove all imperfections from the photo.

Step 10. Optimize the appearance of the image using different tools

Pixlr is equipped with various drawing tools that can eliminate minor imperfections or alter the whole image. Click on one of these tools listed in the appropriate bar, anchored on the left side of the page; then, click on the item Brush, located in the upper left of the page; at this point, you can select the type of brush and the size of the tip. For best results, use one of the round tip brushes with soft edges. These tools include:

Sharpen / Blur / Smudge:

has an icon that resembles a drop. Click on this tool inside the left bar and choose the mode you want next to "Mode" at the top of the panel. Here are the different options:
- Sharpen - use this tool to better define the edges.
- Blur - use this tool to round the sharpest edges.
- Smudge - use this tool to blend individual pixels together.
Sponge / Color:

its icon resembles a sun. Click on this tool from the left bar. You choose Increase or Decrease next to "Mode" in the top panel to increase or decrease the effect. Select the specific method of color correction by clicking on "Method" from the panel at the top according to the options offered:
- Vibrance - this method increases or decreases the intensity of soft colors
- Saturation - this method increases or decreases the intensity of all colors
- Temperatures - increasing this method adds more shades of red or orange; decreasing this method instead adds more shades of blue or purple
Dodge / Burn:

has an icon that looks like a semi-filled circle. Click on this tool from the left bar. Choose the option from the "Mode" button Lighten to lighten parts of an image. Choose instead Darken to darken them. The "Range" button also allows you to choose whether to act on certain color ranges: Shadows, Midtones And Highlights.
Spot Heal it features a double-headed brush icon. Use this tool to remove blemishes and scratches from an image area.

Step 11. Change the brightness and colors of the image

Pixlr provides numerous visual effects that allow you to optimize the colors, brightness, hues and saturation of an image. Follow these instructions to enhance the colors of an image:

Click on the menu Adjustment;
Click on the item Brightness & Contrast or Hue & Saturation;
Use the sliders that appeared to change the level of brightness, contrast, color and saturation of the image;
Click on the button Apply once you get the result you want.

Step 12. Save the new image

After finishing your editing work, save the new image. Images saved with a high quality level will be less compressed and each pixel will have more data. The result you will get in this case will be a large file and a sharper and brighter image. Images saved with low visual quality will be more compressed, however each pixel will be defined by less data. In this case you will get a smaller file size, but the image will be less sharp and bright, definitely more grainy. Follow these instructions to save your work:

Click on the menu File;
Click on the option Save;
Name the new image using the "File name" text field;
Click on the button Download.

Method 2 of 2: Using Adobe Photoshop

Step 1. Launch Photoshop

It is characterized by a blue icon inside which the letters "Ps" are visible. In order to use Adobe Photoshop you need to subscribe. You can purchase and download Photoshop directly from this URL:

If you need to optimize the quality of your images to be able to publish them on platforms like Facebook or Instagram, this method won't help you as much as an application capable of using graphic filters. Pixlr contains a range of free filters that can correct and eliminate the imperfections of a JPEG image. If you want your images to have great feedback and don't care that compressing them will result in a drop in visual quality, try using Pixlr before buying Photoshop

Step 2. Open the image you want to edit in Photoshop

Follow these instructions to open the image to be optimized using Photoshop:

Click on the menu File;
Click on the item You open;
Select the image to open;
Click on the button You open.

Step 3. Save a copy of the image

Before editing a photo or image with Photoshop, it's a good idea to make a copy of it to keep the original intact. In this way, in the event of an error, you can start from scratch with the initial image available. Follow these instructions to make a copy of the original image:

Click on the menu File;
Click on the option Save with name;
Assign a new name to the file by typing it in the "File name" field;
Select the file format to use (for example JPEG, GIF,-p.webp" />
Click on the button Save.

Step 4. Resize the image (optional)

The size of a JPEG file is determined by the resolution of the image, that is, by the number of pixels that compose it. The higher the resolution, the larger the file size. Sharing a large JPEG file via email or uploading and downloading from the web is a time-consuming process. By resizing the image in order to reduce the number of pixels that compose it, you can share or transfer it faster. Note that if you increase the size of an image, it does not increase the visual quality as well. However, reducing the size of an image may also cause a decrease in the number of details. When you decide to change the size of an image do it with small variations to the rate, in order to evaluate the impact they have on the final result. Follow these instructions to resize an image using Photoshop:

Click on the menu Image;
Click on the item Image size;
Enter the desired number of pixels in the "Width" or "Height" text field located at the top of the window;
Click on the button OK.

Step 5. Crop the image

This operation allows to remove, in a simple and quick way, the parts of the photo that are not needed. Deleting parts of an image also reduces the size of the corresponding file. The "Crop" tool features a square icon with the sides of two opposite corners overlapping. It is listed at the top of the toolbar on the left side of the window. Follow these instructions to crop an image:

Click on the tool icon Cut out placed in the toolbar;
Drag the mouse cursor over the area of the image you want to crop and keep;
Use the selection area anchor points, located in the corners, to precisely resize the portion of the photo you want to keep;
Press the button Enter to delete the parts of the image that you have not selected.

Step 6. Locate the "Reduce Noise" filter

It is listed under the "Filter" menu. Follow these instructions to apply the "Reduce Noise" filter:

Click on the menu Filter;
Click on the option I disturb;
Click on the item Reduce Noise.

Step 7. Change the "Reduce Noise" filter settings

Start by selecting the check button Preview, located on the left of the pop-up that appeared. In this way, you will be able to see the visual effect that the filter will have in real time, without directly modifying the image. Now change the position of the filter sliders according to your needs. The options you have available are the following:

Intensity reflects the degree of digital noise in the image that will be eliminated. You should set a high number if you have a low quality JPEG image. Drag the slider to the right to see the impact that a higher filter intensity has on the image in the preview pane.
Keep details is an option that, when set to a low percentage, will result in an unclear image with muted colors. However it will help eliminate much of the digital noise present.
Highlight details is an option that, set to a high value, will compensate for the low percentage of the "Keep details" parameter, in order to highlight the edges of the objects in the image.
Select the check button " Delete JPEG artifactWith this function the program will try to eliminate the jargon-called "mosquito noise" artifacts and the grainy effect that occurs when a JPEG image is saved using a compressed format.
When you are satisfied with the image displayed in the preview box, click on the button OK to apply the filter.

Step 8. Use the "Smart Blur" or "Smart Sharpen" filters

Depending on the needs of the photo, you can use the "Smart Sharpen" filter to sharpen the details in the image or "Smart Blur" to soften them. Proceed as follows:

Click on "Filter" in the menu bar at the top;
Place the cursor on Blur or Sharpen
Click on Smart Blur or Smart Sharpen
Check the box next to "Preview" to preview the effect on the image
Use the sliders to adjust the filter.
- Radius - determines the size of the dots that will be reduced
- Threshold / Amount - determines the color differences needed to identify the dots on which the filter will be applied
Click on Ok

Step 9. Color in the areas of the image that are grainy or have the "mosquito noise" effect

In some places in the image there may be clusters of colored, square-shaped pixels that are poorly defined and detailed (for example, in areas where the sky is displayed, a solid color background, or on clothing). The goal is to make the transition from one image area of a certain color to another as smooth as possible. Do not delete the main details of individual objects. Follow these instructions to correct the parts of the photo where the colors are grainy or the "mosquito noise" effect is present:

Press the key combination " Ctrl And +"in Windows or" Command And +"on Mac to enlarge the areas where there are colored blocks to be deleted;
Click on the toolbar icon depicting an eyedropper to select the "Eyedropper" tool;
Click on the main color of the area you want to change to sample it;
Click on the brush toolbar icon to select the Photoshop "Brush" tool;
Click on the circular icon (or on the type of brush selected) located in the upper left part of the program window to access the "Brush" menu;
Set the "Hardness" parameter to 10%, the "Opacity" parameter to 40% and the "Flow" parameter to 100%;
Press the keys " [" And " ]"to change the size of the brush stroke;
Change the areas to be treated with single mouse clicks.

Step 10. Use the "Clone Stamp" tool on areas of the image that have detailed and irregular textures

For example, it is very useful on elements with a particular grain, such as human skin, plasterboard walls or a paved road. In this case you will not use a single color, because the "Clone Stamp" tool is able to create a sample of a texture or an area of an image and to replicate it exactly in all the points where it is needed, for example for eliminate stains, imperfections or marks. Follow these instructions to use the "Clone Stamp" tool to remove any imperfections or defects in the image:

Click on the Photoshop toolbar icon that looks like a stamp;
Click on the brush toolbar icon to select the Photoshop "Brush" tool;
Set the "Hardness" parameter to 50% or lower;
Set the "Opacity" parameter to 100%;
Press the keys " [" And " ]"to change the size of the brush stroke;
Press and hold the " Alt"in Windows or" Option"on Mac while you click on a point very close to the stain or imperfection you want to remove, so you will acquire the sample of the texture that will be used as a copy;
Click once on the spot where the stain or imperfection to be removed is visible;
Repeat this process to remove any blemishes, blemishes, or spots on the image (remember to acquire a new sample for each of the areas you will need to treat).

Step 11. Optimize the appearance of the image using different tools

Photoshop comes with multiple drawing tools that can eliminate minor imperfections or alter the entire image. Photoshop uses a single icon to group multiple drawing tools within a section. Click on an icon in the toolbar without releasing the left mouse button to view the complete list of all the tools you have available and to be able to choose the one to use. At this point, click on the circular icon (or on the type of tool currently selected), located in the upper left part of the program window, in order to change the type and size of the stroke. Alternatively, you can press the " [" And " ]"to change the stroke size of the tool you've chosen. For best results, use one of the soft-edged round brushes. Here is the list of tools you can use:

Sharpness it features an icon depicting a prism. Use this tool to better define the edges; it is listed in the same group as the "Blur" and "Smudge" tools.
Blurs features a drop icon. Use this tool to round the sharpest edges; it is listed in the same group as the "Sharpness" and "Smudge" tools.
Smudge it features a finger icon. Use this tool to blend individual pixels together; it is listed in the same group as the "Sharpness" and "Blur" tools.
Sponge features a yellow sponge icon. Use this tool to increase or decrease the color saturation level of a specific area; it is listed in the same group as the "Dodge" and "Burn" tools.
Fencing features a black bulb syringe icon. Use this tool to increase the brightness of the image at a specific point; it is listed in the same group as the "Sponge" and "Burn" tools.
It burns it features an icon of a hand with the tip of the index finger and thumb together. Use this tool to darken or shade certain points in the image; it is listed in the same group as the "Fencing" and "Sponge" tools.
Healing brush it features a double-headed brush icon. Use this tool to remove blemishes and scratches from an image area; it is listed in the same group as the "Red Eye" tool.
Red eyes it features an icon depicting a stylized eye. Use this tool to get rid of the flash effect that makes people's eyes appear red. After selecting the corresponding icon, drag the mouse cursor over the entire eye area that you need to correct. This tool is listed in the same group as the "Healing Brush" tool.

Step 12. Change the brightness and colors of the image

Photoshop provides several features that allow you to fine-tune the colors, brightness, hues, and saturation of an image. Follow these instructions to enhance the colors of an image:

Click on the menu Image;
Click on the item Adjustments;
Click on the option Brightness / Contrast or Hue / saturation;
Use the sliders that appeared to change the level of brightness, contrast, color and saturation of the image;
Click on the button OK when you have achieved the result you want.

Step 13. Save the new image

After finishing your editing work, save the new image. Follow these instructions to save your work:

Click on the menu File;
Click on the option Save with name;
Name the new image using the "File Name" text field;
Select the "JPEG" or "PNG" format using the "Save as" drop-down menu;
Click on the button Save.

Advice

Photoshop history can only keep track of a limited number of actions, while a large number of corrections and edits are required to optimize an image. By switching back to normal viewing mode, you may notice that there is an imperfection or an error due to a large number of operations, greater than what the Photoshop history can store and therefore no longer undoable. To overcome this type of problem, you can increase the number of actions that the program can track by accessing the menu Edit and choosing the option Preferences. Click on the item Performance, then type the value 100 (or higher) into the "History states" text field.
If you are working on a photograph, pay close attention to the different shades of color. A blue flower could contain many shades of blue (light and dark), green, purple, brown and so on, depending on the play of light and shadows and reflections. Do your best to preserve or enrich all these colors using the "Brush" tool and a low opacity level. Consider using the "Clone Stamp" tool if you notice a very large number of color tones in a small area of the image.
Don't be afraid to experiment with Photoshop's "Brush" and "Clone Stamp" tool settings, especially as you gain more experience using this type of program. If you are not satisfied with the final effect of a correction or retouch, you can always change the settings you have chosen.