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ThumbsPlus v10 Questions / Interpolation/JPEG options used for Web Page Wizard thumbnails vs. batch mode
« on: 2022-03-27 21:22:41 »
Hi,
I'm trying to figure out what specific interpolation options, JPEG compression parameters, etc. are used by the Web Page Wizard (Alt+F9) to generate thumbnails. What I'd like to be able to do is set up Batch Process to produce the same images, but so far the specific way Web Page Wizard creates them under the hood eludes me.
This is what I'm setting in the Web Page Wizard - that's all I *can* set as far as JPEG options go. No way to select downsampling interpolation or anything, only size and quality:
This is what I'm using for batch mode:
Source image is a TIFF.
The files end up having the same size in pixels, same basic metadata (quality, resolution, JPEG sampling factor, colorspace, whatever else ImageMagick's "idenfity -verbose" spews out), but they're not the same size in bytes and the resulting image is different, visibly so in some cases. Now, I tried changing interpolation and sub-sampling for batch mode, but it doesn't look like I'm getting the same result anyhow.
Now, you're probably asking "why would anyone want to be that particular about this?" and the answer is, the results we've been getting from the Web Page Wizard's thumbnail generation are so good and reliable for the specific types of images we handle that it's still in use over here long after server-side software became capable of generating its own thumbnails and we stopped actually using the generated webpages themselves - however, this approach is becoming increasingly unwieldy and impractical, for a multitude of reasons you can probably guess yourself. Thus, I've been trying to re-create the Web Page Wizard results in Batch Mode, under the assumption that this is what's actually being used under the hood.
The next step would be to either use Python scripting to integrate that batch flow with an automatic upload to a server - or to use the known set of batch mode options to further re-create the result with ImageMagick, which can be then integrated into server-side software and finally get automatic thumbnails that are not crap within the online store itself.
So, what's the exact magic behind Web Page Wizard's thumbnails? Anyone?
I'm trying to figure out what specific interpolation options, JPEG compression parameters, etc. are used by the Web Page Wizard (Alt+F9) to generate thumbnails. What I'd like to be able to do is set up Batch Process to produce the same images, but so far the specific way Web Page Wizard creates them under the hood eludes me.
This is what I'm setting in the Web Page Wizard - that's all I *can* set as far as JPEG options go. No way to select downsampling interpolation or anything, only size and quality:
This is what I'm using for batch mode:
Source image is a TIFF.
The files end up having the same size in pixels, same basic metadata (quality, resolution, JPEG sampling factor, colorspace, whatever else ImageMagick's "idenfity -verbose" spews out), but they're not the same size in bytes and the resulting image is different, visibly so in some cases. Now, I tried changing interpolation and sub-sampling for batch mode, but it doesn't look like I'm getting the same result anyhow.
Now, you're probably asking "why would anyone want to be that particular about this?" and the answer is, the results we've been getting from the Web Page Wizard's thumbnail generation are so good and reliable for the specific types of images we handle that it's still in use over here long after server-side software became capable of generating its own thumbnails and we stopped actually using the generated webpages themselves - however, this approach is becoming increasingly unwieldy and impractical, for a multitude of reasons you can probably guess yourself. Thus, I've been trying to re-create the Web Page Wizard results in Batch Mode, under the assumption that this is what's actually being used under the hood.
The next step would be to either use Python scripting to integrate that batch flow with an automatic upload to a server - or to use the known set of batch mode options to further re-create the result with ImageMagick, which can be then integrated into server-side software and finally get automatic thumbnails that are not crap within the online store itself.
So, what's the exact magic behind Web Page Wizard's thumbnails? Anyone?