low quailty image

[mohit_24041991]

how to low a image size without losing quality so we can upload in website but no matter how much i compress it i wouldn't able to get what i want i am using Photoshop paint nut still no help
800*600 px size 36kb to 50kb without losing any quality
is there any way to do it

 

[TMTOWTSAC]

In lossless compression, there are hard limits to file size at any given resolution and color depth. You simply can't make things any smaller without sacrificing information. What you can do is figure out where you're willing to compromise.

Depending on your image, you may be able to lower the color depth without losing any perceived quality. For example, a 24 bit color image may not be distinguishable to the naked eye from a 16 bit image, depending on the type of image and the color gradients involved. Your software has a variety of compression options, try them out to see which ones produce the best results for each image.

 

[Solandri]

800*600*3 bytes (RGB) is 1.4 MB. So you're already getting a 30-40x compression ratio, which is really good. Compressibility depends on the image, but you probably can't compress it any more without losing quality.

If you're using Photoshop to save JPEGs, you might be able to reduce the file size a little more by excluding the color space info. Older versions of Photoshop would save it by default (I haven't tried it in newer versions since I've moved almost entirely to Lightroom). File -> Save As -> JPEG, and in the dialog box that pops up, towards the bottom there's a check box for Embed Color Profile. Make sure it's unchecked. That can save a few kB. The only consequence is that color space-aware web browsers will now assume your JPEG is sRGB (which it probably already is, and should be for general distribution and use on websites or displaying on TVs). If your JPEGs are not sRGB, then they will appear too saturated or unsaturated on all web browsers, not just browsers which ignore color space.

 

[Pimpom]

When there's no need to alter/edit the content of an image, I use IrfanView almost exclusively for cropping, rotating, resizing, format conversion, palette change and compression. It's light, fast and intuitive.

For lossless compression PNG is the way to go IMHO but, as others have already pointed out, there's a hard limit to how much you can compress in a lossless format. JPEG is lossy by nature no matter how high you set the quality but you can set the compression to any level if you're willing to bear the loss of quality. For images containing only a relatively small number of different colours, such as line drawings and comic book style drawings, a PNG file can be much smaller than JPG. But for an image containing thousands of colours, JPG can compress more.