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#31
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Reducing picture size with same quality.
On Mon, 26 Mar 2012 08:16:35 +0100, "J. P. Gilliver (John)"
wrote: In message , Peter Jason writes: [ I think I have fixed it by using the Irfanview "Resample" option. The photo below is about 160KB, resampled down from the original of 1MB. Note the effective maintaining of the caption at the lower left that compression always trashes to a furry blur. http://imageshack.us/photo/my-images...leirfanvi.jpg/ When I click on the magnifying glass, or just the image, on that, I get something that looks as if it is trying to get me to register; without that I can see that the caption is there, but not read it. I know, Imageshack is not exactly superior; do you know of a better one? The original photo was a JPEG 5.01MB, then imported into PShop CS5, Original being what the camera gave you, I take it. What is it in pixels? I check it out and repost. cropped 6x4 (for wide-screen monitors), exposure adjusted and Or even 3:2 (-: Yes, or even 12x8; but the Dear People here go by the photo-kiosk displays. :-)) sharpened. The resulting JPEG was 1MB and this Irfanview reduced to (IrfanView can crop and sharpen by the way.) What was the 1MB image in pixels? I check it out and repost. 161KB. I emailed this 161KB jpeg size to myself as an "attachment" and it returned the same size with no loss of quality. However if I So it should. What size was the 161KB image in pixels? I check it out and repost. emailed this as a picture insertion the result was somehow returned as only about 50KB and quality was much less and the caption unreadable. What size was that in pixels? I check it out and repost. Why a loss of size as an "insertion" but not with "attachment"? Peter That's a function of your email software. I don't know what you're using, but I have seen email software - or even just the right-click and send-to email recipient function in Windows Explorer (under XP, anyway) - offer to shrink images; if there's a tickbox to always do this and don't ask me again, you might have ticked that at some point. (If so, I don't know how to undo it.) It may be a fixed option in your email software. I use Outlook10 though I have not yet plumbed all its plutonic depths. Call me pixel-obsessed if you wish, but it's important to distinguish between pixel reduction and compression. I check it out and repost. |
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#32
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Reducing picture size with same quality.
On 3/26/2012, J. P. Gilliver (John) posted:
cropped 6x4 (for wide-screen monitors), exposure adjusted and Or even 3:2 (-: Oh come on, what's wrong with 9:6? :-) But I would have expected (and recommended) 32:18 or some such. -- Gene E. Bloch (Stumbling Bloch) |
#33
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Reducing picture size with same quality.
On Sun, 25 Mar 2012 22:33:16 -0400, Paul wrote:
Peter Jason wrote: On Sun, 25 Mar 2012 09:44:46 +0100, "J. P. Gilliver (John)" wrote: In message , Peter Jason writes: On Sat, 24 Mar 2012 15:09:36 -0700, Gene E. Bloch wrote: [] He says he'll need to do some research. OTOH, elsewhere in this thread Bob L recommends using IrfanView's resampling instead of resizing, which I agree with. If the OP uses other software, maybe he can find a similar choice in that software. I have the Irfanview and the size reduction from jpgs was less than stellar. What is resampling? What do you mean by "the size reduction from jpgs"? I can think of several things you might mean, and it'd be useful to know which you mean: o the size reduction by saving in jpg (at the default 80%) compared to a raw format such as bitmap, uncompressed tiff, or raw o the size reduction by saving in jpg at a lower quality o the size reduction by saving at a lower pixel size (e. g. "Half") It'd be useful to know if the "smaller" size pictures your camera produces are the same size in pixels but just a higher compression, or actually a smaller number of pixels. Similarly was the reduction in filesize you were obtaining in Photoshop or whatever it is, a reduction in number of pixels or just higher compression. (You said you were happier with the "small" pictures you got from the camera than the ones you'd reduced in the software.) As for resampling/resizing, I _think_ - as IrfanView uses the terms - it means this: say you're reducing to one third the size (in each axis, i. e. one ninth the number of pixels). A simple way would be to take every third pixel. This can lose significant aspects - say you had three pixels that were white black white, representing a single black line; the line could disappear altogether. I think that might be what IV means by resizing, since it says that's faster. The other way involves taking some account of the content of the discarded pixels. Thanks I think I have fixed it by using the Irfanview "Resample" option. The photo below is about 160KB, resampled down from the original of 1MB. Note the effective maintaining of the caption at the lower left that compression always trashes to a furry blur. http://imageshack.us/photo/my-images...leirfanvi.jpg/ The original photo was a JPEG 5.01MB, then imported into PShop CS5, cropped 6x4 (for wide-screen monitors), exposure adjusted and sharpened. The resulting JPEG was 1MB and this Irfanview reduced to 161KB. I emailed this 161KB jpeg size to myself as an "attachment" and it returned the same size with no loss of quality. However if I emailed this as a picture insertion the result was somehow returned as only about 50KB and quality was much less and the caption unreadable. Why a loss of size as an "insertion" but not with "attachment"? Peter On an "insertion", did you use Windows Live Mail and the picture is actually stored on a Skydrive ? If so, perhaps Microsoft shrank the picture a bit when stored on their server. The thing about "attachment", is no other things should play with it, when it's sent. The "attachment" option should make you more in control of the situation. If you weren't using Windows Live Mail, then insertion and attachment could end up working the same way. I'm using Outlook10 You could try placing the caption on it, later in the process, to avoid a bit of fuzziness but not all of it. If you use JPEG for the final compression, that has to fuzz the text. You could also store the caption in the metadata of the JPEG. I see an EXIF section in the picture, with my hex editor, where the camera "E-5" is identified. Perhaps there'd be some way to put the caption in there. The caption has always been a problem. When I scanned in about 2000 family photos, some going back to 1885, a large proportion were anonymous and there was no-one left alive to identify the people, time or location. I resolved that this would never happen with mine. At first I had a discreet border at the bottom of the photo on which I placed the text, but the photo kiosks have a knack of trimming this off partly or completely. Hence I plaster the text on the body of the photo, and not too near the edges either. There are precedents.... http://hoocher.com/Henry_VIII/Elizabeth_of_York.jpg Naturally I want to do the caption only once, so I need to have the caption readable at reasonable reductions. As a test, you could edit the 5.01MB JPEG, and when saving out your email copy (not your archival copy), select a quality setting of 10%, for a compression of 50:1. That would shrink the picture to around the same size as the 90KB I just got from your Imageshack.us link. You'd get to keep all the pixels, but with degradation in shading. You should be able to do that in Photoshop (although, in this dialog, I don't understand how a Q=10 is the same thing as "Maximum", unless they mean maximum compression). http://photoshopcall.com/wp-content/...utorial-03.jpg Paul |
#34
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Reducing picture size with same quality.
In message , Peter Jason
writes: [] The caption has always been a problem. When I scanned in about 2000 family photos, some going back to 1885, a large proportion were (Ah, genealogical work? Hobby of mine too!) anonymous and there was no-one left alive to identify the people, time or location. I resolved that this would never happen with mine. At first I had a discreet border at the bottom of the photo on which I placed the text, but the photo kiosks have a knack of trimming this off partly or completely. Hence I plaster the text on the body of the photo, and not too near the edges either. There are precedents.... http://hoocher.com/Henry_VIII/Elizabeth_of_York.jpg (-: Naturally I want to do the caption only once, so I need to have the caption readable at reasonable reductions. You can embed it - as text - into a JPEG file; in IrfanView, have the image on screen, then press I then C. This has the advantage that you can add a sizeable paragraph of text (I don't know if there is actually any limit). I _think_ the writing back of the file (to save the text comment) _doesn't_ involve recompressing the image and hence adding another layer of corruption, though I'm not 100% sure of that. (You could easily find out with an image comparison routine like DupDetector.) [] -- J. P. Gilliver. UMRA: 1960/1985 MB++G.5AL-IS-P--Ch++(p)Ar@T0H+Sh0!:`)DNAf What's awful about weird views is not the views. It's the intolerance. If someone wants to worship the Duke of Edinburgh or a pineapple, fine. But don't kill me if I don't agree. - Tim Rice, Radio Times 15-21 October 2011. |
#35
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Reducing picture size with same quality.
On 26/03/2012 6:12 PM, J. P. Gilliver (John) wrote:
You can embed it - as text - into a JPEG file; in IrfanView, have the image on screen, then press I then C. This has the advantage that you can add a sizeable paragraph of text (I don't know if there is actually any limit). I _think_ the writing back of the file (to save the text comment) _doesn't_ involve recompressing the image and hence adding another layer of corruption, though I'm not 100% sure of that. (You could easily find out with an image comparison routine like DupDetector.) What you see on the screen is a decompressed image, a bitmap in fact (of course - think about it!) So Save in JPEG format always recompresses the image. In Irfan view and XnView, you can set the default compression, which IMO should be set to high quality. HTH, Wolf K. |
#36
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Reducing picture size with same quality.
In message , Wolf K
writes: On 26/03/2012 6:12 PM, J. P. Gilliver (John) wrote: You can embed it - as text - into a JPEG file; in IrfanView, have the image on screen, then press I then C. This has the advantage that you can add a sizeable paragraph of text (I don't know if there is actually any limit). I _think_ the writing back of the file (to save the text comment) _doesn't_ involve recompressing the image and hence adding another layer of corruption, though I'm not 100% sure of that. (You could easily find out with an image comparison routine like DupDetector.) What you see on the screen is a decompressed image, a bitmap in fact (of course - think about it!) So Save in JPEG format always Yes, I know (-:. recompresses the image. In Irfan view and XnView, you can set the default compression, which IMO should be set to high quality. HTH, Wolf K. I _think_ adding the comment field via I, C in IrfanView - assuming you were starting with a JPEG image in the first place - doesn't recode. I think it just moves the - compressed - data further down the file to make room for the comment text. -- J. P. Gilliver. UMRA: 1960/1985 MB++G.5AL-IS-P--Ch++(p)Ar@T0H+Sh0!:`)DNAf Hit any user to continue. |
#37
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Reducing picture size with same quality.
On 26/03/2012 7:49 PM, J. P. Gilliver (John) wrote:
In message , Wolf K writes: On 26/03/2012 6:12 PM, J. P. Gilliver (John) wrote: You can embed it - as text - into a JPEG file; in IrfanView, have the image on screen, then press I then C. This has the advantage that you can add a sizeable paragraph of text (I don't know if there is actually any limit). I _think_ the writing back of the file (to save the text comment) _doesn't_ involve recompressing the image and hence adding another layer of corruption, though I'm not 100% sure of that. (You could easily find out with an image comparison routine like DupDetector.) What you see on the screen is a decompressed image, a bitmap in fact (of course - think about it!) So Save in JPEG format always Yes, I know (-:. recompresses the image. In Irfan view and XnView, you can set the default compression, which IMO should be set to high quality. HTH, Wolf K. I _think_ adding the comment field via I, C in IrfanView - assuming you were starting with a JPEG image in the first place - doesn't recode. I think it just moves the - compressed - data further down the file to make room for the comment text. Visually, what happens is that you place the text (with or without transparent background) anywhere you like. This implies that it's overlaid on the image data at that location, and the whole thing is recompressed when the image is saved. Any other way of doing it would limit correct decoding of the imge data to software that understood how Irfanview or XnView added text. BTW, font size is measured in pixels, and is absolute, so that if you use the same font with large (say 4000x3000) and resized (say 2400x1800), the text will take up a larger portion of the smaller image. This too implies that the text data is overlaid. HTH Wolf K. |
#38
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Reducing picture size with same quality.
In message , Wolf K
writes: On 26/03/2012 7:49 PM, J. P. Gilliver (John) wrote: [] I _think_ adding the comment field via I, C in IrfanView - assuming you were starting with a JPEG image in the first place - doesn't recode. I think it just moves the - compressed - data further down the file to make room for the comment text. Visually, what happens is that you place the text (with or without transparent background) anywhere you like. This implies that it's overlaid on the image data at that location, and the whole thing is recompressed when the image is saved. Any other way of doing it would limit correct decoding of the imge data to software that understood how Irfanview or XnView added text. BTW, font size is measured in pixels, and is absolute, so that if you use the same font with large (say 4000x3000) and resized (say 2400x1800), the text will take up a larger portion of the smaller image. This too implies that the text data is overlaid. HTH Wolf K. Adding text to the comment field does not make it visible in the image. It places text in a place within the file that can be retrieved by any viewer capable of looking at that field. It's like the EXIF data that records camera details etcetera. Thus it need not - and I believe does not, at least when done in IrfanView - affect the image in any way. -- J. P. Gilliver. UMRA: 1960/1985 MB++G.5AL-IS-P--Ch++(p)Ar@T0H+Sh0!:`)DNAf "When I was young I used to scintillate now I only sin 'til ten past three" (Ogden Nash) [via Andy Breen] |
#39
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Reducing picture size with same quality.
On 27/03/2012 3:06 AM, J. P. Gilliver (John) wrote:
Adding text to the comment field does not make it visible in the image. It places text in a place within the file that can be retrieved by any viewer capable of looking at that field. It's like the EXIF data that records camera details etcetera. Thus it need not - and I believe does not, at least when done in IrfanView - affect the image in any way. Sorry, I overlooked that "comment field". I don't use it, put basic data (copyright notice and often subject/date/location) in/on image itself. But thanks for the reminder, will have to experiment with comment field. AIUI, it's metadata, like EXIF. Wolf K. |
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