Professional and Affordable Web Design
0800 080 5401
Sharpen photographs using Photoshop's high pass filter
This is a very simple tutorial which demonstrates using Photoshop\'s high pass filter to sharpen an image.
This tutorial is most likely to be of interest to people using digital cameras. or to webdesigners and artists wishing to sharpen images.
Why do images need sharpening?
Many digital photographs can appear to be slightly out of focus, either on screen or printed.
Photoshop\'s sharpening tools can usually do a good job when provided with good quality images. They do this by enhancing the contrast on the edges of images - no extra digital information is added to the image (in fact, some information is lost) but images with sharper edges appear to "jump out of the page".
In this tutorial, we are demonstrating using the high pass filter to sharpen images.
Always make a duplicate of your original image
When working with images in Photoshop, we always recommend "non destructive" methods of enhancement. This means creating a duplicate layer of the original image, and applying any effects to that layer.
If the worst happens and the photopshop file is saved, and you later wish to go back and edit or undo any changes, you have the original image to work on - stored as a layer.
Firstly, we will duplicate the layer. This can be done by selecting the original image and pressing "CTRL + A" to select its entire contents. Then pressing "CTRL + J" will create a duplicate layer.
We then set the blend mode of the duplicate layer to "overlay".
The overlay blend mode effectively enhances the contrast of the darker and lighter regions of the image.
Regions of exactly 50% brightness are unaffected. Brightness below this point effectively has the Multiply blend applied; Brightness above 50% has the Screen blend mode applied.
With the original layer duplicated and set to Overlay mode, the on screen result looks like the contrast has been boosted (like the layer curves have been set to an S curve).
Applying the Filter > Other > High pass will show a dialog box, and a preview image (set to grayscale).
The slider adjusting the radius of the High pass filter can be adjusted until the preview window only contains the edges of objects in the image. This effect will, when applied, serve to visually sharpen the edges of objects visible.
We recommend using as low a value as possible, to avoid introducing "Halo" effects into our completed image.
Halo effects become visible with excessive sharpening, as light "blooms" around dark edges in the image.
If the image looks good on screen, its ideal for our purposes.
Sharpening an image for printing
If the image is intended for printing, it is worth doing a test run - some images may look sharp on screen, but when printed the end result is still not sharp.
This depends on the image size, and the specific printer and paper type. It may be that additional sharpening is required for printing purposes.
All comments are moderated for spam and will not be shown. All genuine comments wil be show, however the links will be based on a NO FOLLOW RULE. Repeat commenters adding value to the articles and discusions will have removed alowing Follow Rule to Work.
Make a Comment
See Full Portfolio Some Of Our Work
Driving Schools Booking Service (DSBS) is a network of driving instructors, covering the whole of the UK. For this project, we were...
County Security is a fully featured E - commerce solution, with an integrated "system configurator", which allows users to choose...
Customer News & Resources
At Mutiny Design we are constantly gathering together articles and help guides to assist our clients.Introduction to sitemap.xml
Checking for a sitemap A site map (or sitemap) is a list of pages of a web site accessible to crawlers or users. It can be either a document in any form used as a planning tool for web design, or a web page that lists the pages on a web site, Some developers feel that site index is a more appropriately used term to relay page function, web visitors are used to seeing each term and generally associate both as one and the same. However, a site index is often an A-Z index that provides access to content, while a site map provides a general... Read More »Center a web page in CSS
One simple way to center a web page using CSS is to create a container div, that is horizontally centered by having its left and right margins set to auto. Using this method, you can still apply colours / background images to the body tag, so its a flexible solution. (if you didnt need this ability, just apply margins and width to the body tag instead, and forget using the container div). The container div has the same width as your webpage and, well, contains it. All the code for your web page is placed inside the container div. This will... Read More »