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Photo optimization is done for reducing the loading time of a web page. It is observed that the patience level of the online visitors is very low. So, they prefer to click out of those sites that take more time to get downloaded.
Computer monitors can usually display images at 72dpi. So, the primary step in the photo editing is to decrease the resolution to at 72dpi. In order to do so big pictures can be sliced up into small pieces and then they are being inserted on the web page. Since each of the pages are treated as small files they are loaded within a couple of seconds and do not take as much time a single image file would take for downloading.
Many graphic programs provide the option of “Save for the web”, which discards all the unimportant information in the file without effecting the quality of picture. Apart from this, PNG or GIF or JPEG progressive property can also be used for making the loading time faster.
- Height and Width IMG Attributes - In order to hold the graphic the HTML <img> tags instruct the web browser to create a box. Thus the browser is able to continue loading of the other web pages while the graphic file is itself downloading. On the other hand, if you have not inserted the height and width attributes the web browser has to stop before loading the rest of the pages until the images are get loaded.
- How many Images should be used? - Images no doubt make a site look visually appealing, but at the same time too much insertion of images increases the loading time of a site. It is observed that the images take around 50% of the total downloading time of a site. So, it is always better to avoid too much use of images in a site.
- Quality of Photo- Photo quality is determined on the basis of color purity, clarity and detail of a photo. In order to produce quality images graphic editor should be used. It will remove noise as well as other irrelevant features and can also adjust the color levels and can change the background. Apart from this, by using Google Page Speed tool you can do the image optimization that will ultimately help to improvise the performance of your website.
- Guidelines of Photo Optimization- Some of the points that the web developers of a website design company follows while editing photos are listed below:
- Conversion of graphic text into stylized text.
- Changing the resolution of all images to 72dpi.
- Cropping the images to the actual size required.
- Specifying the actual height and width of all images.
- Minimizing depth of color when it is not needed for quality.
- Using thumbnails where required.
While developing a website design, it is mandatory to keep all those points in mind. Otherwise you may loose your visitors forever.
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Do what you like with a DPI setting. It will have absolutely no effect on how an image is displayed on a computer monitor. The setting is only active when printing an image and is an instruction to said printer how many dots per inch to print - hence DPI.
It is such a widespread misconception that I am not surprised you have made the same error.
Nice comment Mark and thank you for it.
Always been wondering about the DPI setting effect on image display for the web. Now I know.
Appreciated
leon