The main problem associated with increasing the size of raster images is that the graphics editor has nowhere to take information about the color of pixels that are added to the picture to enlarge it. The program copies the existing pixels and, as a result, the enlarged image loses much as the original picture. If it is impossible to avoid increasing the linear dimensions of the file, after the end of the transformation, the image must be corrected.
Necessary
Photoshop program
Instructions
Step 1
The most famous way to increase the size of a picture using standard Photoshop tools is to successively resize by ten percent using the Image Size option from the Image menu. To use this method, open the size settings window and change pixels to percentages in the Pixel Dimentions panel. Enter 110% in any of the fields on this panel. Select Bicubic as the interpolation method and click on the OK button.
Step 2
If you need to enlarge the picture by ten to twenty percent, the image quality will not suffer much. However, preview the edited picture by zooming in to one hundred percent in the Navigator panel. It may turn out that the color noise present in the original image has increased with the picture and has become more noticeable. Remove noise with the Reduce Noise filter from the Noise group of the Filter menu.
Step 3
If compression artifacts become noticeable in certain areas of the image, if possible, remove them using the Clone Tool. To do this, place the cursor on an image fragment painted in the same color as the edited area, but without artifacts. Hold down the alt="Image" key and click on this area. Click on the editable section of the image. Pixels from the area that was selected as the cloning source will be copied to it.
Step 4
Duplicate the layer using the Dublicate Layer option from the Layer menu. Sharpen the duplicate layer by first switching it to the Lab color mode using the Lab option from the Mode group of the Image menu. In the dialog box that appears, click on the Don't Merge button to save the layers.
Step 5
In the Channels tab, click on the Lightness channel and apply the Unsharp Mask filter to it. To see the result of applying the filter to a color image, click on the Lab channel.
Step 6
Switch the picture back to RGB mode. Adjust the opacity of the filter layer to achieve the best blend of crisp and fuzzy images.
Step 7
Save the enlarged image to a.jpg"
