Optimizing Consistent Size Thumbnails

I have a question about optimizing thumbnail sizes for a gallery page of kitchens that my cabinet shop produces. The size of this gallery page is going to grow over time. I am concerned about download speed for this initial page.

One of the good pieces of fortune I have is that my customers are highly motivated and hungry for information. They will endure a little pain if they can get access to knowledge that they want. The first thing I have to do is sell them on the idea that they can get this knowledge from me. Download speed on this first page is the only one I am concerned about.

In other words, I think the quality can be a little lower on Gallery Page if after they click into one kitchen they are rewarded with compelling copy.

I park a SITE IMAGE inside one of Will Woodgate’s LINKBOX Stacks. (I can’t remember if I paid you for this Will, but I am good for it.) There is also an H6 heading with an ID number for the kitchen. I use this combination because it’s real easy for a customer and myself to talk about Kitchen 13 and both find the same information quickly.

I do all of my post processing in Adobe Lightroom. In order to maintain a consistent size graphic in the SITE IMAGES I export one jpeg for each kitchen in a 4X5 Aspect Ratio. This jpeg is then compressed in IMPAGE OPTIM software.

I remember reading somewhere on this forum about exporting first for the size of the image then optimizing second. The drift of this argument was that if the container that was going to hold the image was 300 pixels wide, any extra pixels that are downloaded are going to get thrown away but still need to be transported across the network anyway.

How do I go about determining what the optimum size graphic would be to start with so that I don’t export anymore data than necessary?

Is there some optimum preset in Lightroom that can produce thumbnails for this combination of stacks in RapidWeaver?

On most websites, images are sized according to their width. To determine how many pixels wide your image should be you need to determine what the largest width (in pixels) the image will be displayed on your site.

Depending on your layout, this may not be the desktop version of your website. It may be the mobile version, if you are showing the images one per row. It all depends on how may images you’re showing on the same row in your design.

Once you know the size in pixels, you can then play with lossy compression. I don’t use Lightroom, but in Photoshop, this is the “Quality” setting when you save a jpg image. The lower the quality, the lower the size. Go too low and your image will not look as clear.

Finally, I would then run a loss-less compression on the images, to ensure you get all the optimization you can. ImgOptim can do loss-less or lossy compression. I prefer to do my lossy compression in Photoshop (or similar) and loss-less in ImgOptim. For lossy compression you usually need to see how it’s affecting the image. Lossless should not affect how an image looks.

It may seem like we’re not directly answering your questions. We’re not because it all depends on the site design, the images, etc. For example, some images can take a lot more lossy compression and still look good, while other can’t tolerate nearly as much. You need to try different amounts of compression and look at the resulting images and decide if you’re happy with them.

What is the difference between “lossy” compression and “loss-less” compression?

Lots of good info on Google: lossy vs lossless compression