[racket] Artefact when cropping and scaling an image

Version 6.0 is the next one and we're pretty late in the release cycle,
yep. You can follow along on the dev@ mailing list.

Robby


On Mon, Nov 18, 2013 at 6:45 PM, Daniel Prager <daniel.a.prager at gmail.com>wrote:

> Thanks for checking it out -- sounds like it may be fixed / one for the
> test suite.
>
> Will 5.3.7 be coming soon?
>
> Dan
>
>
> On Tue, Nov 19, 2013 at 11:40 AM, Robby Findler <
> robby at eecs.northwestern.edu> wrote:
>
>> Ah. I'm not sure which change affected this, but in the git version from
>> last night I see a solid red square (and I do see the same thing as you in
>> 5.3.6).
>>
>> Robby
>>
>>
>> On Mon, Nov 18, 2013 at 6:36 PM, Daniel Prager <daniel.a.prager at gmail.com
>> > wrote:
>>
>>> Image attached.
>>>
>>> System: Mac, OS X 10.8.5, Racket 5.3.6.
>>>
>>> Dan
>>>
>>>
>>> On Tue, Nov 19, 2013 at 11:28 AM, Robby Findler <
>>> robby at eecs.northwestern.edu> wrote:
>>>
>>>> I'm not seeing what you're seeing, I think. Can you send a screenshot
>>>> (or a pointer to it)?
>>>>
>>>> Robby
>>>>
>>>>
>>>> On Mon, Nov 18, 2013 at 5:59 PM, Daniel Prager <
>>>> daniel.a.prager at gmail.com> wrote:
>>>>
>>>>> Why does the following code generate visual artefacts along the right
>>>>> and bottom
>>>>> edges of the image?  How do I eliminate it?
>>>>>
>>>>> #lang racket
>>>>> (require 2htdp/image)
>>>>>
>>>>> (define (crop-to-aspect-ratio im final-width final-height)
>>>>>   (let* ([W (image-width im)]
>>>>>          [H (image-height im)]
>>>>>          [wh-ratio (/ final-width final-height)]
>>>>>          [w (* wh-ratio H)]
>>>>>          [h (/ W wh-ratio)]
>>>>>          [image (if (<= W w)
>>>>>                     (crop 0 (/ (- H h) 2) W h im)
>>>>>                     (crop (/ (- W w) 2) 0 w H im))])
>>>>>     (freeze (scale (/ final-width (image-width image))
>>>>>                    image))))
>>>>>
>>>>> (scale 5
>>>>>        (crop-to-aspect-ratio
>>>>>         (freeze (rectangle 259 356 'solid 'red))
>>>>>         40 56))
>>>>>
>>>>>
>>>>> Note that the two freeze instructions are essential -- the one in the
>>>>> crop routine
>>>>>  forces pixelation, which I want -- and the one in the calling code
>>>>> simulates starting with a bitmap.
>>>>>
>>>>> Thanks
>>>>>
>>>>> Dan
>>>>>
>>>>> ____________________
>>>>>   Racket Users list:
>>>>>   http://lists.racket-lang.org/users
>>>>>
>>>>>
>>>>
>>>
>>>
>>> --
>>> *Daniel Prager*
>>> Agile/Lean Coaching, Software Development and Leadership
>>> Twitter: @agilejitsu <https://twitter.com/agilejitsu>
>>> Blog: agile-jitsu.blogspot.com
>>>
>>
>>
>
>
> --
> *Daniel Prager*
> Agile/Lean Coaching, Software Development and Leadership
> Twitter: @agilejitsu <https://twitter.com/agilejitsu>
> Blog: agile-jitsu.blogspot.com
>
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