Pixalo Photography Community

Go Back   Pixalo Photography Community > Photography Forums > General photography questions and answers

General photography questions and answers: Discuss Cropping without affecting quality?...Hi I have a photograph that I want to crop part out of. Every time I try though it reduces ...
Welcome to the Pixalo Photography Community. As a Guest you are free to browse the site, but see what extras you get as a Member here.


Reply
 
LinkBack Thread Tools Display Modes
Old 18-01-2008, 21:05   #1 (permalink)
Getting Comfy
 
Helena's Avatar
 
Join Date: Oct 2006
Location: Hampshire, UK
Posts: 166
Helena will become famous soon enoughHelena will become famous soon enoughHelena will become famous soon enoughHelena will become famous soon enoughHelena will become famous soon enoughHelena will become famous soon enough
User's Gallery
Users Camera Equipment List
Question Cropping without affecting quality?

Hi
I have a photograph that I want to crop part out of. Every time I try though it reduces the quality of the photograph. Is there a way to crop a photo without reducing the quality?

Even resaving the same file without changing anything seems to reduce the quality. I use Paint Shop Pro and I've checked the compression is set to minimum.

Anyone offer any advice?
Thanks
Helena is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 18-01-2008, 23:00   #2 (permalink)
Loves the place
 
Rob Barron's Avatar
 
Join Date: Sep 2006
Location: Poole, Dorset
Posts: 7,227
Rob Barron is a name known to allRob Barron is a name known to allRob Barron is a name known to allRob Barron is a name known to all
Rob Barron is a name known to allRob Barron is a name known to allRob Barron is a name known to allRob Barron is a name known to allRob Barron is a name known to allRob Barron is a name known to allRob Barron is a name known to allRob Barron is a name known to allRob Barron is a name known to allRob Barron is a name known to allRob Barron is a name known to all

Image editing O.K.
User's Gallery
Users Camera Equipment List
Re: Cropping without affecting quality?

Hi Helena, a lot depends on what size your picture is before you start cropping and what resolution it is. Obviously you can't expect to crop a 72dpi shot very much and make the resulting one as large as the original as there just aren't enough pixels to do it properly.

The thing you should NOT do is to crop and enlarge in one movement. So don't have the sizes of the width and height set when you do the cropping as this forces the software to interpolate upwards in a big jump. First crop, then enlarge the remaining picture.

One tip I picked up a few years ago now and have stuck by ever since is this:

If you want to upsize a picture, do it in small increments. So rather than trying to increase a picture by 50% in one go, increase it by 10% five times. The result is invariably a much better quality that way.

There are software progs that do an amazing job of enlarging pictures really well with low quality loss but generally they're quite expensive.

One last thing, it could be nothing more than you are cropping and then viewing the picture at the same size as the original on your computer monitor and so it is looking lower quality. Have you tried actually printing out the result to compare it with the original? You may well find it hasn't lost the quality that you think it has. But you do need to be working with a printing resolution, ie between 240 and 300 dpi.

Cheers,
Rob
__________________
Rob Barron

I love being a photographer: it's the only job where you can legally shoot people and cut their heads off
Rob Barron is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 18-01-2008, 23:26   #3 (permalink)
Loves the place
 
JMitchell's Avatar
 
Join Date: Jan 2007
Location: Berlin
Posts: 4,945
JMitchell is a glorious beacon of lightJMitchell is a glorious beacon of light
JMitchell is a glorious beacon of lightJMitchell is a glorious beacon of lightJMitchell is a glorious beacon of lightJMitchell is a glorious beacon of lightJMitchell is a glorious beacon of lightJMitchell is a glorious beacon of lightJMitchell is a glorious beacon of lightJMitchell is a glorious beacon of light

Image editing O.K.
User's Gallery
Users Camera Equipment List
Re: Cropping without affecting quality?

rob's answer is good, however in answer to your comment about losing quality when resaving, that is unfortunately an inherent defect of the jpg file format. This is why many people immediately save their jpgs as .tiff files which do not suffer (well, not really) from saving compresion.
JMitchell is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 19-01-2008, 00:44   #4 (permalink)
Forum Regular
 
Join Date: Jan 2007
Location: I conduct workshops in Andalucia, Spain
Posts: 782
Les Meehan is a jewel in the rough
Les Meehan is a jewel in the roughLes Meehan is a jewel in the roughLes Meehan is a jewel in the roughLes Meehan is a jewel in the roughLes Meehan is a jewel in the roughLes Meehan is a jewel in the roughLes Meehan is a jewel in the rough

Image editing O.K.
User's Gallery
Users Camera Equipment List
Re: Cropping without affecting quality?

Quote:
Originally Posted by JMitchell View Post
rob's answer is good, however in answer to your comment about losing quality when resaving, that is unfortunately an inherent defect of the jpg file format. This is why many people immediately save their jpgs as .tiff files which do not suffer (well, not really) from saving compresion.
I picked up the same thought as Jack from your post. JPEG is one of the 'lossy' file formats, it discards pixel data as it compresses, and so you should never resave a jpeg image if you want to retain quality since it applies the compression each time you save the file. TIFF is one of the 'lossless' formats and can be saved multiple times without loss of quality as it does not discard pixel info.

So Jack's advice about saving a jpeg as a tiff is sound practice. Better still set your camera to save as tiff files if possible.
Les Meehan is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 19-01-2008, 01:14   #5 (permalink)
Getting Comfy
 
snap2photo's Avatar
 
Join Date: Sep 2007
Location: Cheltenham, UK
Posts: 159
snap2photo will become famous soon enoughsnap2photo will become famous soon enoughsnap2photo will become famous soon enoughsnap2photo will become famous soon enoughsnap2photo will become famous soon enoughsnap2photo will become famous soon enough

Image editing O.K.
User's Gallery
Users Camera Equipment List
Re: Cropping without affecting quality?

I'm not sure that the "jpeg is rubbish" is the whole answer here.

Are you loosing the quality in the print? There is sometimes "stuff" in the JPEG file to help with printing that is lost if you edit and save. (or just open and resave).

I think the lower end Fuji does not have colour managment stuff, but the higher end ones may have. Sometimes this is lost in the resave proccess. If you have the controls on the camera try using sRGB, not adobe colour model.

Is the "quality" the contrast, colour, sharpness or artifacts?
snap2photo is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 19-01-2008, 01:18   #6 (permalink)
Loves the place
 
silkstone's Avatar
 
Join Date: Jan 2005
Location: Silkstone Common, Yorkshire, UK
Posts: 5,719
silkstone is a glorious beacon of lightsilkstone is a glorious beacon of light
silkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of light

Image editing O.K.
User's Gallery
Users Camera Equipment List
Re: Cropping without affecting quality?

As so often, I'll swim against the tide here.

Quote:
Originally Posted by Helena
Even resaving the same file without changing anything seems to reduce the quality. I use Paint Shop Pro and I've checked the compression is set to minimum.
Are you sure? PSP works the opposite way round from many editors, so the lower the value the higher the quality.

Choose Save As and then click on Options. Set the value to 5.

The theory goes that every time you resave a JPG it is compressed a little more and therefore degraded. But this does depend on a lot of things...

Some while ago I did a little test in PSP. I opened a JPG, resaved (with the quality set to 5), and then closed the file. Then I reopened the file again, resaved, closed..... 10 times.

The finished product was, perhaps, marginally degraded from the original, but nothing like as much as I had expected. My flabber was, in fact, totally gasted.

JPEGs are much maligned IMHO. It depends on the image and the software's JPEG algorithm, but you should be able to get really good results if you don't resave too often.

I suppose I'm going to have to repeat this now just to show that I'm not talking a load of dingos' kidneys. I won't do it right now - maybe over the weekend.

I hope I get the same results.
__________________
I answer to "Silky", "Paul" and "miaow".
silkstone is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 19-01-2008, 03:55   #7 (permalink)
Feet under the table
 
j sotelo's Avatar
 
Join Date: Nov 2006
Location: San Diego, Ca. Where the Surf meets the Turf
Posts: 3,235
j sotelo is a glorious beacon of lightj sotelo is a glorious beacon of lightj sotelo is a glorious beacon of light
j sotelo is a glorious beacon of lightj sotelo is a glorious beacon of lightj sotelo is a glorious beacon of lightj sotelo is a glorious beacon of lightj sotelo is a glorious beacon of lightj sotelo is a glorious beacon of lightj sotelo is a glorious beacon of lightj sotelo is a glorious beacon of light

Image editing O.K.
User's Gallery
Users Camera Equipment List
Re: Cropping without affecting quality?

I remember there was a similar thread a while back some of the info might help.
http://www.pixalo.com/community/gene...age-18535.html
it was about upsizing, but again, some info might help.
j sotelo is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 19-01-2008, 06:09   #8 (permalink)
Forum Regular
 
Willow5075's Avatar
 
Join Date: Oct 2007
Location: Adelaide, South Australia- best place in the world
Posts: 1,379
Willow5075 will become famous soon enoughWillow5075 will become famous soon enoughWillow5075 will become famous soon enoughWillow5075 will become famous soon enoughWillow5075 will become famous soon enoughWillow5075 will become famous soon enoughWillow5075 will become famous soon enoughWillow5075 will become famous soon enough

Image editing O.K.
User's Gallery
Users Camera Equipment List
Re: Cropping without affecting quality?

So I just had a trial run at your suggestion Silkstone. Are you suggesting that 5 is good as a default setting.

Mine default (not having touched it since I started using PSP about 3 or 4 weeks ago) was around 25.
Willow5075 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 19-01-2008, 06:46   #9 (permalink)
Pixalo Crew
 
Markulous's Avatar
 
Join Date: Jul 2006
Location: Peak District
Posts: 19,640
Markulous is a jewel in the rough
Markulous is a jewel in the roughMarkulous is a jewel in the roughMarkulous is a jewel in the roughMarkulous is a jewel in the roughMarkulous is a jewel in the roughMarkulous is a jewel in the rough

Image editing O.K.
User's Gallery
Users Camera Equipment List
Re: Cropping without affecting quality?

Depending on the image, saving and resaving a JPEG will degrade the image - one of the reasons I moved from my Fuji S602 to dSLR was the in-camera interpolation which could go soft in some areas (and saving/re-saving definitely made it worse!)

BTW, the DPI setting on an image is totally irrelevant at the edit/save stage - used for printing only
Markulous is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 19-01-2008, 09:20   #10 (permalink)
Getting Comfy
 
Helena's Avatar
 
Join Date: Oct 2006
Location: Hampshire, UK
Posts: 166
Helena will become famous soon enoughHelena will become famous soon enoughHelena will become famous soon enoughHelena will become famous soon enoughHelena will become famous soon enoughHelena will become famous soon enough
User's Gallery
Users Camera Equipment List
Re: Cropping without affecting quality?

Thank you everyone for all your replies! Part of the reason I am asking is that I want to enter this photo in a competition which means it will get printed out very large - possibly around A2 size. Had I known I'd have a fab photo I'd want to enter I'd have made sure my camera was set to its maximum 6M setting...but I didn't...but I've ended up with a photo I love and want to enter. The jpg file is big enough even after a crop to display that big so I think it will be okay, but I just wanted to see if there was anything I could do to make extra sure I didn't loose the quality at that size.

Unfortunately the competition only accepts jpg format, but I'll bear in mind the other formats for others things.
Helena is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 19-01-2008, 14:03   #11 (permalink)
Loves the place
 
silkstone's Avatar
 
Join Date: Jan 2005
Location: Silkstone Common, Yorkshire, UK
Posts: 5,719
silkstone is a glorious beacon of lightsilkstone is a glorious beacon of light
silkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of light

Image editing O.K.
User's Gallery
Users Camera Equipment List
Re: Cropping without affecting quality?

Quote:
Originally Posted by Willow5075 View Post
So I just had a trial run at your suggestion Silkstone. Are you suggesting that 5 is good as a default setting.

Mine default (not having touched it since I started using PSP about 3 or 4 weeks ago) was around 25.
Yes, I find that 5 is a good default. 25 is far too high - anything over 15 can produce noticeable artifacts.
silkstone is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 19-01-2008, 23:21   #12 (permalink)
Forum Regular
 
Dave Canon's Avatar
 
Join Date: Nov 2006
Location: Cheltenham
Posts: 1,290
Dave Canon is just really nice
Dave Canon is just really niceDave Canon is just really niceDave Canon is just really niceDave Canon is just really niceDave Canon is just really niceDave Canon is just really niceDave Canon is just really niceDave Canon is just really niceDave Canon is just really nice
User's Gallery
Users Camera Equipment List
Re: Cropping without affecting quality?

Silkstone, your test will not really reveal the problem with resaving JPEGs. If you open then save the same unedited image any deterioration will be minor. However, if you edit the picture (even minor editing) then the input to the JPEG algorithm is different and a different set of approximations takes place. You only need to do this about 6 - 8 times to seriously damage the image. See the two examples below of a JPEG image before and the same image saved 8 times with very minor editing. You may not be able to see the editing but you can see the artifacts on the instrument and music.

Before



After

__________________
Regards Dave

http://www.image001.co.uk
Dave Canon is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 20-01-2008, 01:03   #13 (permalink)
Forum Regular
 
Willow5075's Avatar
 
Join Date: Oct 2007
Location: Adelaide, South Australia- best place in the world
Posts: 1,379
Willow5075 will become famous soon enoughWillow5075 will become famous soon enoughWillow5075 will become famous soon enoughWillow5075 will become famous soon enoughWillow5075 will become famous soon enoughWillow5075 will become famous soon enoughWillow5075 will become famous soon enoughWillow5075 will become famous soon enough

Image editing O.K.
User's Gallery
Users Camera Equipment List
Re: Cropping without affecting quality?

Quote:
Originally Posted by silkstone View Post
Yes, I find that 5 is a good default. 25 is far too high - anything over 15 can produce noticeable artifacts.
Thanks fpr that tip I'll keep mine at 5 now that I know.
Willow5075 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Old 20-01-2008, 02:09   #14 (permalink)
Loves the place
 
silkstone's Avatar
 
Join Date: Jan 2005
Location: Silkstone Common, Yorkshire, UK
Posts: 5,719
silkstone is a glorious beacon of lightsilkstone is a glorious beacon of light
silkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of lightsilkstone is a glorious beacon of light

Image editing O.K.
User's Gallery
Users Camera Equipment List
Re: Cropping without affecting quality?

Quote:
Originally Posted by Dave Canon View Post
Silkstone, your test will not really reveal the problem with resaving JPEGs. If you open then save the same unedited image any deterioration will be minor. However, if you edit the picture (even minor editing) then the input to the JPEG algorithm is different and a different set of approximations takes place. You only need to do this about 6 - 8 times to seriously damage the image....
Very good point, Dave. But it does depend on the compression settings and also the algorithm that the software uses. At the risk of going slight OT, I'm happy to do a RAW conversion straight to (low compression) JPEG, using Bibble + plugins which does not require second-stage editing for most pics, and go back to the original later for any tweaks. I'm happy to work on the JPEG for resizing etc, provided I don't resave more than once. What I try to avoid like the plague is a load of TIFFs - especially 16 bit - that just chew up disk space.

P.S. The ideal solution would be PNG which is compressed but lossless, except that it loses the EXIF data.
silkstone is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Photoshop Cropping chrisa Photo Manipulation 4 02-11-2007 18:34
Basic Cropping rivanprincess Photo Manipulation 5 18-08-2007 17:48
Quicktime exploit affecting MySpace users Steve Computer hardware, software, networking and internet 0 23-03-2007 10:35
Composition/ Cropping Advice.... InaGlo Photo Critique 7 01-03-2006 21:44
cropping and how much... barrymoir General photography questions and answers 17 26-02-2006 22:30


All times are GMT +1. The time now is 20:29.


vBulletin Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
ReviewPost & PhotoPost vB3 Enhanced, Copyright 2003-2014 All Enthusiast, Inc.
SEO by vBSEO 3.3.0
Copyright © 2006 - 2017 Pixalo.com

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197