The other day I discovered that some JPEGs I'd posted to my (self-hosted) WordPress blog had been compressed. The subject of my blog happens to be anaglyph 3D photos... and if the images are not saved at a very high resolution, a phenomenon called "ghosting" or "crosstalk" appears, where parts of the image that are only supposed to be visible to one eye are visible to the other eye as well. This can ruin the 3D effect. So it's important that my images are uploaded and posted with no added compression. The problem is that I don't know exactly where the problem occurred. Details below... These particular images got to my blog somewhat circuitously: after exporting them from Photoshop on my PC at a very high resolution, I attached them to a Gmail message... then I downloaded them to my iPad's photo gallery... and then I uploaded them to the blog via the iPad WordPress app. Upon viewing the posted images, I could see a very definite degradation of image quality.
What I'm trying to figure out is which step in the chain caused this. I've sent image files thru Gmail many times, and never noticed any compression, so I'm assuming/hoping that's not where it happened.
I know that Apple often has stuff going on under the hood of its hardware and software that isn't clearly explained to users (which is why I've been wary of the iPad, and have only started using this hand-me-down unit recently). So it's my prime suspect. I looked for settings that might control image compression, but couldn't find anything that mentioned it or would allow me to prevent it from happening.
Then there's WordPress. When I upload multiple photos using the WordPress Media Uploader on the PC, there is a message that appears that says "Crunching..." My research suggests that the original images are not being compressed during this process, but rather that multiple image sizes are being created. Ultimately I've decided to upload images from my PC by inserting them individually into posts; the Media Uploader seems to handle this without any visible quality loss. But what the iPad WordPress app may or may not be doing to my images is still a mystery to me.
I'd really like to know where the problem occurred. It would be nice to be able to upload stuff from the iPad to the blog -- if this unwanted compression can be eliminated. I'm also thinking about buying the iPad Camera Connection Kit... but I don't want to try moving photos from my cameras thru the iPad to email or cloud storage, if it's going to mess them up.
Can anyone shed any light?
What I'm trying to figure out is which step in the chain caused this. I've sent image files thru Gmail many times, and never noticed any compression, so I'm assuming/hoping that's not where it happened.
I know that Apple often has stuff going on under the hood of its hardware and software that isn't clearly explained to users (which is why I've been wary of the iPad, and have only started using this hand-me-down unit recently). So it's my prime suspect. I looked for settings that might control image compression, but couldn't find anything that mentioned it or would allow me to prevent it from happening.
Then there's WordPress. When I upload multiple photos using the WordPress Media Uploader on the PC, there is a message that appears that says "Crunching..." My research suggests that the original images are not being compressed during this process, but rather that multiple image sizes are being created. Ultimately I've decided to upload images from my PC by inserting them individually into posts; the Media Uploader seems to handle this without any visible quality loss. But what the iPad WordPress app may or may not be doing to my images is still a mystery to me.
I'd really like to know where the problem occurred. It would be nice to be able to upload stuff from the iPad to the blog -- if this unwanted compression can be eliminated. I'm also thinking about buying the iPad Camera Connection Kit... but I don't want to try moving photos from my cameras thru the iPad to email or cloud storage, if it's going to mess them up.
Can anyone shed any light?