answersLogoWhite

0

Sometimes our customers give us JPEG pictures at 72DPI. Even worst is when these pictures need to be enlarged, ending up with something like 16 DPI…

For the cases where there is no other sources, we have refined a process to be able to print at 720 DPI on our large format printer with satisfactory results, commonly so good that a normal viewer will not discern the difference with a picture originally at 150 or 300DPI.

But let's start with pictures of a real case example that we handled just last week, before giving you the recipe

cropped and zoomed detail of the original picture and improved picture, both zoomed 400% to see the defects on a screen resolution:

Original Picture

And now the same area after our processing

Improved Picture

Quite impressive, right ? And remember this is a 400% zoom i.e. the improved image really have no scales and almost no blur at 100%.

As can be seen, while you can't really generate details that are not in the picture, you still can greatly improve the actual aspect by applying a few simple techniques, trying and choosing them on the final effect you want to achieve.

Here are the details for Photoshop but they should be applicable to others image processing software.

The simpler and usually starting point is to increase the resolution by step [instead of in one time], ex: double from 72 to 144 to let's say 360 than 720, using different smoothing algorithms.

I also recommend to start your process by changing the depth from 8 bits to 16 bits before doing these resolution increased, and to revert back to 8 bits only at the end, right before printing. This should reduce the moire and flat surfaces.

And you can do some final sharpening/blurring and noise reduction/noise addition as the last step[s].

They are also a few plug-ins available that claim to achieve excellent results. I tried them, and while they results are better than just doing a simple pass DPI increase, I prefer my process that allow me to proceed stage by stage and reach my expected level of quality in a more controlled manner.

This will work really nicely for an originally good 72DPI picture, like the example above, and is time intensive, not to mention you need a strong CPU, lots of memory and better a SSD if your picture size is big. So, I do this as part of my preparation process before printing, since I always print files that I have pre-converted to the right resolution, color mod/profile and saved as TIFF, cause I don't trust the RIP engines

If you start with a low quality level JPEG picture than it's a little bit more challenging, you better start by applying JPEG removal artefact algorithms.

This is the kind of thing we do on a daily basis for our customers as part of Plixo's ultra large format printing services, most of the time we don't even tell customers about it but they tend to notice and ask how we manage to get such results

Hope this helps.

User Avatar

Wiki User

13y ago

What else can I help you with?

Related Questions

Did the first digital cameras have high resolution or low resolution?

They had a low resolution


How do you change a low resolution picture into a high resolution picture on Adobe Photoshop Elements 9?

Image > Image Size


How do you know if an image is high resolution or low resolution?

You could tell because low resolution makes for a pixelated picture, and high resolution settings, you cannot tell.


How do you change low to high resolution pictures?

Open image in Photoshop then go to Image > Image Size.


Did the first digital cameras high or low resolution?

yes when the first came out but now compare to today they are low resolution


How do you zoom in the camera for Samsung Rant SPH-M540?

You need to change the Resolution to either High, Medium or Low. If you have it set to 2M or 1.3M the zoom does not work. Once you change the resolution, use the left and right keys to zoom in and out.


What is better high magnification and low resolution or low magnification and high rosultion?

It depends on the specific use case. High magnification and lower resolution would be better for observing fine details in a smaller area, while low magnification and high resolution would be better for seeing the bigger picture with greater clarity.


How do you change low resolution pictures into high resolution?

The best way to decrease the resolution of digital artwork is to open it with Adobe Photoshop. Then go to the top of the screen and click Image > Image Size > and change the number in the box labeled "resolution." Be sure that "Resample Image" is checked so that it will discard the extra resolution, rather than reallocating it. Then Save As, and you're done.


When I take a picture does a low resolution image records faster than a high resolution?

no they record at the same rate but the low resolution is of lower quality and smaller file size than the higher resolution image.


How do you convert high resolution 3gp video to low resolution 3gp video?

convert it to avi format


How do you convert Low resolution video to high resolution?

I think this is so called restoration you can do this by means or using an especial equipment or hardware. Generally you can't get a low resolution video to a high resolution, some of these restorations can work to varying degrees. There are also software that lets you edit the resolution of the video outputs.


What causes low resolution?

Low resolution is usually caused by a poor compression rather than poor capture. Low resolution images have less physical pixels than a high resolution one. The stretching of the image is what causes them to look poor. This low number of pixels is usually the result of downsampling of the the image for email or file size purposes.